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HomeMy WebLinkAbout14-275FOR OFFICE USE ONLY CASE NO.: \ 4 -2. -vs CITY or C oILEGE STATION Home o/TtxaJ A&M Univmity• DATE SUBMITTED: \ I I \2/14 TIME: \o·.oo SITE PLAN APPLICATION GENERAL STAFF: _,_/\-:1"""'-------- MINIMUM SUBMITTAL REQUIREMENTS: ~, ~932 Site Plan Application Fee. ~ ·$35d' Non-Residential Architectural Standards I Northgate Building Review Application Fee (if applicable). ~ $600 (minimum) Development Permit Application I Public Infrastructure Review and Inspection Fee. Fee is 1 % of acceptable Engineer's Estimate for public infrastructure, $600 minimum (if fee is > $600, the balance is due prior to the issuance of any plans or development permit). ~ Application completed in full. This application form provided by the City of College Station must be used and may not be adjusted or altered. ~ Six (6) folded copies of site plan. ~ One (1) folded copy of the landscape plan. ~ One (1) copy of the following for Non-Residential Architectural Standards building review or Northgate Building Review (if applicable). ~ Building elevations to scale for all buildings. ~ A list of building materials for all facade and screening. ~ Color samples for all buildings or list colors to be used from the approved color palette. ~ Electronic copy of Site Plan e-mailed to csuelectdesign@cstx.gov. ~ Two (2) copies of the grading, drainage, and erosion control plans with supporting drainage report. ~ Two (2) copies of the Public infrastructure plans and supporting documents (if applicable). D Traffic Impact Analysis or calculations of projected vehicle trips showing that a TIA is not necessary for the proposed request (if applicable). ~ The attached Site Plan Non-Residential Architectural Standards Building Review and Northgate Building Review checklists (as applicable) with all items checked off or a brief explanation as to why they are not check off. Date of Optional Preapplication or Stormwater Management Conference NAME OF PROJECT Brazos Valley Floor and Design ADDRESS 12900 Old Wellborn Road LEGAL DESCRIPTION (Lot, Block, Subdivision) Lot 10, Block 1, Rock Prairie West Business Park APPLICANT/PROJECT MANAGER'S INFORMATION (Primary contact for the project): Name Jeremy Peters -Gessner Engineering E-mail jpeters@gessnerengineering.com Street Address 2501 Ashford Drive, Suite 102 City College Station State TX Zip Code 77840 ------- Phone Number (979) 680-8840 Fax Number (979) 680-8841 ---------------~ PROPERTY OWNER'S INFORMATION: Name Moreau Family Investments -Chuck Moreau E-mail chuck@bvcarpetoutlet.com Street Address 1834 Ha"is Drive City College Station State TX Zip Code 77845 -------~ ------~ Phone Number (979) 218-8835 Fax Number ---------------~ Revised 4/14 Page 1 of 11 ARCHITECT OR ENGINEER'S 11\IFORMATION: Name Jeremy Peters -Gessner Engineering E-mai 1 jpeters@gessnerengineering.com Street Address 2501 Ashford Drive, Suite 102 City College Station State TX Zip Code _7_78_4_0 ____ _ Phone Number (979) 680-8840 Fax Number (979) 680-8841 ----------------- 0 THE R CONTACTS (Please specify type of contact): Name Street Address City _________ Zip Code Phone Number Fax Number ----------------- Current zoning POD -------------------------------------- Present use of property Granite Sales ____ ...;...__ ____________________________ _ Proposed use of property Granite Sales ---------------------------------- Number of parking spaces required 44 Number of parking spaces proposed 44 -------- Is there Special Flood Hazard Area (Zone A or Zone AE on FEMA FIRM panels) on the property? I Yes IX No This information is necessary to help staff identify the appropriate standards to review the application and will be used to help determine if the application qualifies for vesting to a previous ordinance. Notwithstanding any assertion made, vesting is limited to that which is provided in Chapter 245 of the Texas Local Government Code or other applicable law. Is this application a continuation of a project that has received prior City platting approval(s) and you are requesting the application be reviewed under previous ordinance as applicable? I Yes I No If yes, provide information regarding the first approved application and any related subsequent applications (provide additional sheets if necessary): Project Name: City Project Number (in known): Date I Timeframe when submitted: Revised 4/14 Page 2 of 11 MULTl-FAMIL Y RESIDENTIAL Total Acreage Floodplain Acreage ____ _ Housing Units ___ #of 1 Bedroom Units ___ #of 2 Bedroom Units # of 3 Bedroom Units --- #of 4 Bedroom Units --- FOR 2 BEDROOM UNITS ONLY #Bedrooms= 132 sq. ft. --- #Bedrooms< 132 sq. ft. --- PARKLAND DEDICATION (Fees due prior to the issuance of a Building Permit) #of Multi-Family Dwelling Units x $1636 = $ # of acres in floodplain #of acres in detention #of acres in greenways Date dedication approved by Parks & ____ Recreation Advisory Board , COMMERCIAL Total Acreage Building Square Feet ___ _ Floodplain Acreage ____ _ * Projects that were vested prior to January 1, 2008, per Chapter 245 of the Texas Local Government Code may be assessed a different amount. Please contact city staff for additional information. repared this application and certifies that the facts stated herein and exhibits attached hereto are true /! /;z.-(14- Date Revised 4/14 Page 3 of 11 CERTIFICATIONS REQUIRED FOR ALL DEVELOPMENT Owner Certification: 1. No work of any kind may start until a permit is issued. 2. The permit may be revoked if any false statements are made herein. 3. If revoked, all work must cease until permit is re-issued. 4. Development shall not be used or occupied until a Certificate of Occupancy is issued. 5. The permit will expire if no significant work is progressing within 24 months of issuance. 6. Other permits may be required to fulfill local, state, and federal requirements. Owner will obtain or show compliance with all necessary State and Federal Permits prior to construction including NOi and SWPPP. 7. If required, Elevation Certificates will be provided with elevations certified during construction (forms at slab pre- pour) and post construction. 8. Owner hereby gives consent to City representatives to make reasonable inspections required to verify compliance. 9. If, stormwater mitigation is required, including detention ponds proposed as part of this project, it shall be designed and constructed first in the construction sequence of the project. 10. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that all debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply. 11 . The information and conclusions contained in the attached plans and supporting documents will comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines Technical Specifications, and Standard Details. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 12. Release of plans to (name or firm) is authorized for bidding purposes only. I understand that final approval and release of plans and development for construction is contingent on contractor signature on approved Development Permit. 13. I, THE OWNE GREE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR THE D P NT PERMIT APPLICATION , ARE, TO THE BEST OF MY KNOWLEDGE, TRUE, AND X ACC d-zcUef-_ Property Owner(s) Date Engineer Certification: 1. The project has been designed to ensure that stormwater mitigation, including detention ponds, proposed as part of the project will be constructed first in the construction sequence. 2. I will obtain or can show compliance with all necessary Local, State and Federal Permits prior to construction including NOi and SWPPP. Design will not preclude compliance with TPDES: i.e., projects over 10 acres may require a sedimentation basin. 3. The information and conclusions contained in the attached plans and supporting documents comply with the current requirements of the City of College Station , Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 4. I, THE ENGINEER, AGREE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR THE DEVELOR ENT PERMIT APPLICATION, ARE, TO THE BEST OF MY KNOWLEDGE, TRUE, AND ACCURATE. /1//1 //'1 Date Revised 4/14 Page 4of 11 CITY OF C OLLEGE STATION Home of Texas A&M Univmity" SITE PLAN MINIMUM REQUIREMENTS (ALL CITY ORDINANCES MUST BE MET) INCLUDING BUT NOT LIMITED TO THE FOLLOWING: [8] Sheet size -24" x 36" (minimum). [8] A key map (not necessarily to scale). [8] Title block to include: [8] Name, address, location, and legal description [8] Name, address, and telephone number of applicant [8] Name, address, and telephone number of developer/owner (if differs from applicant) [8] Name, address, and telephone number of architect/engineer (if differs from applicant) [8] Date of submittal [8] Total site area [8] North arrow. [8] Scale should be largest standard engineering scale possible on sheet. [8] Ownership and current zoning of parcel and all abutting parcels. [8] The total number of multi-family buildings and units to be constructed on the proposed project site. [8] The density of dwelling units per acre of the proposed project. [8] The gross square footage of all buildings and structures and the proposed use of each . If different uses are to be located in a single building, show the location and size of the uses within the building. Building separation is a minimum of 15 feet w/o additional fire protection. Locations of the following on or adjacent to the subject site: Designate between existing and proposed [8] The density of dwelling units per acre of the proposed project. [8] Phasing. Each phase must be able to stand alone to meet ordinance requirements. [8] Buildings (Existing and Proposed). [8] Setbacks according to UDO, Article 5. Geography [8] Water courses. [8] 100 yr. floodplain and floodway (if applicable) on or adjacent to the proposed project site. Please note if there is none on the site with confirming FEMA/FIRM map number. [8] Existing topography (2' max or spot elevations) and other pertinent drainage information. (If plan has too much information, show drainage on separate sheet.) [8] Proposed grading (1 ' max for proposed or spot elevations) and other pertinent drainage information. (If plan has too much information, show drainage on separate sheet.) Revised 4/14 Page 7 of 11 Streets, Parking, and Sidewa."s [8.J Existing streets and sidewalks (R.O.W.). [8.J Existing Driveways, both opposite and adjacent to the site according to UDO, Article 7. [8.J Proposed drives. Minimum drive aisle width according to UDO, Article 7 [8.J Indicate proposed driveway throat length according to UDO, Article 7 ~ Proposed curb cuts. [8.J For each proposed curb cut (including driveways, streets, alleys, etc.) locate existing curb cuts on the same and opposite side of the street to determine separation distances between existing and proposed curb cuts. [8.J Proposed curb and pavement detail. [8.J A 6" raised curb is required around all edges of all parts of all paved areas without exception. (To include island, planting areas, access ways, dumpster locations, utility pads, etc.) No exception will be made for areas designated as "reserved for future parking". [R] Proposed medians. [8.J Proposed sidewalks (both public and private). [R] Proposed pedestrian/bike circulation and facilities for non-residential buildings (UDO, Article 7). [R] Off-Street parking areas with parking spaces drawn, tabulated, and dimensioned. [R] Designate number of parking spaces required by ordinance and provided by proposal. [R] Handicap parking spaces. [R] Parking Islands drawn and dimensioned with square footage calculated according to UDO, Section 7.2 or 7.9 fornon- residential buildings. [R] Parking setback from R.O.W. to curb of parking lot as required. !RI Wheelstops may be required when cars overhang onto property not owned by the applicant or where there may be conflict with pedestrian or bike facilities, handicap accessible routes or above ground utilities, signs or other conflicts. [8.J Security gates, showing swing path and design specs with colors. [R] Guardrails. Include design and colors. [R] Traffic Impact Analysis for non-residential development (UDO, Article 7). [R] Please note if none is required. [R] Will there be access from a TxDOT R.O.W.? O Yes [Rj No If yes, then TxDOT permit must be submitted with this application. Easements and Utilities [R] Easements -clearly designate as existing or proposed and type (utility, access, etc.) [R] Utilities (noting size and designate as existing or proposed) within or adjacent to the proposed site, including building transformer locations, above ground and underground service connections to buildings, and drainage inlets. [R] Sewer Design Report (if applicable). [R] Water Design Report and/or Fire Flow Report (if applicable). [R] Drainage Report with a Technical Design Summary. [R] Meter locations, existing and proposed (must be located in public R.O.W. or public utility easement). [R] Provide a water and sanitary sewer legend to include [R] Minimum water demands [R] Maximum water demands [R] Average water demands in gallons per minute, and [8.J Maximum sewer loadings in gallons per day [8.J Will there be access from a TxDOT R.O.W.? O Yes [8.J No If yes, then TxDOT permit must be submitted with this application. Revised 4/14 Page 8of11 Fire Protection lg] Show fire lanes. Fire lanes with a minimum of 20 feet in width with a minimum height clearance of 14 feet must be established if any portion of the proposed structure is more than 150 feet from the curb line or pavement edge of a public street or highway. [8] Show proposed and existing fire hydrants. Fire hydrants must be located on the same side of a major street as a project, and shall be in a location approved by the City Engineer. Any structure in any zoning district other than R-1 , R-1A. or R-2 must be within 300 feet of a fire hydrant as measured along a public street, highway or designated fire lane. NOTE: Fire hydrants must be operable and accepted by the City, and drives must have an all weather surface before a building permit can be issued. lg] Will building be sprinkled? lg] Yes O No If the decision to sprinkle is made after the site plan has been approved, then the plan must be resubmitted . If Yes, [8] Show fire department connections. FDC's should be within 100' of the fire hydrant. They shall be accessible from the parking lot without being blocked by parked cars or a structure. Landscaping [8] Landscape plans as required in Article 7 of the Unified Development Ordinance. The landscaping plan can be shown on a separate sheet if too much information is on the original site plan. If requesting protected tree points, then those trees need to be shown appropriately barricaded on the landscape plan. Attempt to reduce or eliminate plantings in easements. Include information on the plans such as: [RI required point calculations [8] additional streetscape points required. Streetscape compliance is required on all streets. 1v1 calculations for # of street trees required and proposed (proposed street tree points will accrue toward total ~ landscaping points.) [8] proposed new plantings with points earned [8] proposed locations of new plantings [8] screening of parking lots, 50% of all shrubs used for screening shall be evergreen. 1v1 screening of dumpsters, concrete retaining walls, off street loading areas, utility connection points, or other ~ areas potentially visually offensive. [8] existing landscaping to remain 1v1 show existing trees to be barricaded and barricade plan. Protected points will only be awarded if barricades are ~ up before the first development permit is issued. [81 Buffer as required in Article 7 of the Unified Development Ordinance. lg] Show irrigation system plan. (or provide note on how irrigation system requirement will be met prior to issuance of C. O.) All plans must include irrigation systems for landscaping. Irrigation meters are separate from the regular water systems for buildings and will be sized by city according to irrigation demand submitted by applicant and must include backflow prevention protection. [8] Is there any landscaping in TxDOT R.O.W.? D Yes [8] No If yes, then TxDOT permit must be submitted at the time of application. Other [8] Common open spaces sites [8] Loading docks [8] Detention ponds lg] Retaining walls lg] Sites for solid waste containers with screening .. Locations ~f d~mpste:s are a.c~essible but not visible.from streets or residential areas. Gates are discouraged and visual screening 1s required. (Minimum 12 x 12 pad required.) [8] Are there impact fees associated with this development? D Yes [81 No NOTE: Signs are to be permitted separately. Revised 4/14 Page 9of11 CITY 01' COLLEGE STATION Homt of Texas A&M Univmity• NRA BUILDING REVIEW MINIMUM REQUIREMENTS (ALL CITY ORDINANCES MUST BE MET) INCLUDING BUT NOT LIMITED TO THE FOLLOWING: Refer to UDO Section 7.9 Non-Residential Architectural Standards, as appropriate. ~ Sheet size -24" x 36" (minimum). ~ Title block to include: ~ Name, address, location, and legal description ~ Name, address, and telephone number of applicant ~ Name, address, and telephone number of developer/owner (if differs from applicant) ~ Name, address, and telephone number of architect/engineer (if differs from applicant) ~ Date of submittal ~ Scale should be largest standard scale possible on sheet. ~ List of colors from the City of College Station color palette to be utilized or proposed equivalents. ~ Color samples. ~ List of materials to be utilized. ~ Elevations of each non-residential building and screening structure. Show placement of materials and colors on the facades according to UDO Section 5.6.B or 7.9. ~ Include the following dimensions: ~ Total vertical square footage minus openings (for each fa9ade separately) ~ Total vertical square footage of transparency (for each fa9ade separately in Northgate) ~ Total vertical square footage of each building material (for each fa9ade separately) ~ Total vertical square footage of each color (for each fa9ade separately) ~ Graphic representation and/or description of existing buildings in building plot to show material, color, and architectural harmony. Revised 4/14 Page 10 of 11 CITY OF COLLEGE STATION Home a/Texas A&M University" FOR OFFICE USE ONLY CASE NO.: DATE SUBMITTED: _____ _ TIME: STAFF: PLANNING & DEVELOPMENT SERVICES TRANSMITTAL LETTER Please check one of the options below to clearly define the purpose of your submittal. [g] New Project Submittal D Incomplete Project Submittal -documents needed to complete an application . Case No.: D Existing Project Submittal. Case No.: Project Name Brazos Valley Carpet Outlet Contact Name Jeremy Peters ---------------~ Phone Number (979) 680-8840 We are transmitting the following for Planning & Development Services to review and comment (check all that apply): D Comprehensive Plan Amendment D Rezoning Application D Conditional Use Permit D Preliminary Plan D Final Plat D Development Plat [g] Site Plan D Special District Site Plan D Special District Building I Sign [g] Landscape Plan D Non-Residential Architectural Standards D Irrigation Plan D Variance Request [g] Development Permit D Development Exaction Appeal D FEMA CLOMA/CLOMR/LOMA/LOMR [g] Grading Plan D Other -Please specify below INFRASTRUCTURE AND ENGINEERING DOCUMENTS All infrastructure documents must be submitted as a complete set. The following are included in the complete set: D Comprehensive Plan Amendment [g] Waterline Construction Documents D TxDOT Driveway Permit D Sewerline Construction Documents D TxDOT Utility Permit D Street Construction Documents [g] Drainage Letter or Report D Easement Application D Fire Flow Analysis D Other -Please specify Special Instructions: 10/10 Print Form May 29, 2014 Gessner Engineering Job No. 11-0355 Prepared for: Moreau Family Investments, Ltd. Mr. Chuck Moreau In Accordance with: Unified Stormwater Design Guidelines City of Bryan/City of College Station Prepared by: GESSNER ENGINEERING, LLC College Station, Texas DRAINAGE DESIGN REPORT Brazos Valley Floor and Design College Station, Texas G May 29, 2014 Mr. Alan Gibbs, P.E. City Engineer City of College Station 1101 Texas Avenue College Station, TX 77840 Re: Storm Water Drainage Study Brazos Valley Floor and Design 12900 Old Wellborn Road College Station, Texas Gessner Engineering Job No.: 11-0355 Dear Mr. Gibbs, 2 This report conveys the results of the storm water drainage study conducted by Gessner Engineering for the proposed redevelopment of Brazos Valley Floor and Design, College Station, Texas. Gessner Engineering believes that all information contained in this report is valid . Please contact us if you have any questions or if we can be of further assistance. This report for the drainage design for Brazos Valley Floor and Design was prepared by Gessner Engineering in accordance with provisions of the Bryan/College Station Unified Stormwater Design Guidelines for the owner of the property. Sincerely, GESSNER ENGINEERING LLC, F-7451 Melissa P. Thomas, P.E. Joshua B. Van Wie, E.l.T., M .S. !ft> ........... ~' ---~OFT \\ ,,. ..._~'\ .......... f.t:., ,, -~~ ... · * ·· ... ., .. f :..( ............ ~f ?::~l'Jf l MELISSA P. THOMAS Z r··························· .. ·~ I. ..i·. 98398 .. ~J f ttO).,· .. ~fCEM~~···~ J' ,, ~.,~········~ -\\,. 10HA\. _..:"' '''"' ... - 3 TABLE OF CONTENTS EXECUTIVE SUMMARY ........................................................................................................................... 4 INTRODUCTION ...................................................................................................................................... 4 CALCULATIONS ....................................................................................................................................... 5 Time of Concentration ................................................................................................................. 5 Unit Hydrograph .......................................................................................................................... 6 Reach Routing .............................................................................................................................. 6 Peak Runoff Flow ......................................................................................................................... 6 Peak Post-Developed Runoff Flow ............................................................................................... 7 CONCLUSION .......................................................................................................................................... 7 APPENDIX Appendix A: General Location Map Appendix 8: FEMA 100 Year Floodplain Map Appendix C: Drainage Area Map and Calculations Appendix D: Hydrographs Appendix E: HEC-HMS Calculations Appendix F: Technical Design Summary Gessner Engineering G - 4 EXECUTIVE SUMMARY This storm water drainage report is submitted to the City of College Station, Texas for review on April 2, 2014 by Melissa P. Thomas, P.E. of Gessner Engineering, located at 2501 Ashford Drive, Suite 102, College Station, Texas 77840. The proposed project consists of the demolition of the asphalt pavement serving the current building and construction of a 15,000 square foot (SF) warehouse and associated new concrete parking. The site will be served by two detention ponds in series. The total area of construction is approximately 2.38 acres. The subject site currently contains a 2,434 SF retail building to remain, a 1,963 sf metal canopy, a 1,112 sf metal awning, and a 24,631 SF of existing parking lot and hardscape all to be removed. The site is located directly northwest of the intersection of Old Wellborn Road and N. Graham Road. The site is located in the Hopes Creek watershed. The site is not located in the FEMA 100 year flood plain, as shown by FIRM number 48041C0310E. This firmette is included as Appendix B. Runoff from the overall drainage area generally flows south until reaching N. Graham Road. Water then flows southwest through a small drainage ditch along N. Graham Road until reaching a tributary of Hopes Creek. Runoff from the subject site reaches N. Graham Road by sheet flow and shallow concentrated flow through a small channel in the center of the property. Runoff from the Carpet Outlet site is stored in a detention pond in the southern corner of the property and discharged to flow across the property to the southwest of both lots until reaching N. Graham Road. Under existing conditions, the total flow exiting the lot and reaching the drainage ditch on N. Graham Road is 16.3 cubic feet per second (cfs) at the peak of the 100 year, Type Ill, 24 hour storm event. After development, runoff will be stored in a series of two detention ponds on the subject property and discharged at the southern corner of the property directly into the ditch along N. Graham Road . Under proposed conditions the flow into the drainage ditch is 15.7 cfs, at the same storm event. Additionally, a small portion of the two driveways along the north property line discharges 0.2 cfs onto the existing Brazos Valley Floor and Design site at the same storm event. The total peak flow of the subject tract under the proposed conditions is 15.9 cfs . The post-developed peak flow is below the pre-developed peak at the 100 year storm event and does not create any issues for downstream properties. INTRODUCTION This storm water drainage report is intended to determine the required detention to match pre- developed storm runoff conditions for the proposed Brazos Valley Floor and Design. The entire Gessner Engineering G 5 drainage area contributes to the drainage ditch along N. Graham Road. The point of contribution to the ditch was used for both pre-developed and post-developed conditions analysis. Drainage Calculations for this site were prepared according to the National Resource Conservation Method as detailed in Technical Release SS (TR-SS} published in June of 1986. Proposed improvements include a lS,000 SF building and S0,130 SF concrete pavement and approximately 8,140 SF of detention area. Curve numbers from TR-SS were used based on developed uses as described above. Pre-developed flows were calculated based on the existing development for the subject site and based on undeveloped conditions for the Carpet Outlet tract. The calculated pre- developed and developed flows include the two (2}, five (S}, ten (10}, twenty-five (2S), fifty (SO) and one-hundred (100) year storms in accordance with the Bryan/College Station Unified Stormwater Design Guidelines. CALCULATIONS Calculations were performed according to the USDA TR-SS and with the aid of HEC-HMS 3.S by the U.S. Army Corps of Engineers. The output data from HEC-HMS has been provided as Appendix E. Time of Concentration The time of concentration (travel time) for each drainage area was estimated by summing the flow time for each segment of travel. For sheet flow, travel time was estimated by Manning's Kinematic equation: 0.007 x (nL )0·8 t =-----/ So.4 ,JP; Where: tt = travel time (hours) n = manning's roughness coefficient L = flow length (feet) s = slope (ft/ft) P2 = 2-year, 24 hour rainfall (inches) For shallow concentrated flow, the travel time was calculated from the flow velocity based on the slope in the direction of flow. These velocities were taken from Table C-4 of the Bryan College Station Unified Stormwater Design Guidelines. Gessner Engineering G • 6 The computed times of concentration for each drainage area are included in Appendix E. Computed values were increased to a minimum time of six (6} minutes as required, based on Chapter 3 of TR-55 which limits the minimum Time of Concentration to 0.1 hour or six (6} minutes. Unit Hydrograph A generic unit hydrograph was computed by distributing the rainfall depths (Table 1} according to the distribution factors for the NCRS Type Ill 24 hour storm. This hydrograph was then applied to each subarea based on the curve number and time of concentration of that area. Reach Routing Hydrographs were routed from subareas to the outflow through the kinematic wave method. This method allows for hydrographs to be translating with time, but not attenuating. The effects of backwater flow and pressure flow in channels were neglected. Peak Runoff Flow Peak Runoff Flow from the site was determined based on the Type Ill 24 hour storm applied to each drainage area. The depth-duration-intervals for each frequency are included in Table 1 below, and were obtained from Table C-6 in the Unified Stormwater Design Guidelines. Curve Number values (CN} were determined from Table C-7, Appendix C of the Unified Stormwater Design Guidelines. Peak pre-developed flows for the subject site adjacent to N. Graham Road are included in Table 1. Drainage areas and calculations are included on sheet CS.O and CS .1, which are attached in Appendix C. Rainfall Depth (in), 24-hr Pre-Developed Peak Flow Frequency duration (ds) 2 year 4.50 5.6 10 year 7.40 10.4 25 year 8.40 12.5 50 yea r 9.80 14.1 100 year 11.00 16.3 Table 1: Rainfall Depths and Resulting Flows Peak Post-Developed Runoff Flow The post-developed peak flows compared to the pre-developed peak flows are shown in Table 2 below for each storm event. Hydrographs for each storm event are included as Appendix D. Gessner Engineering G - 7 Pre-Developed Post-Developed Post-Develop ed Total Post- Storm Peak Flow at Peak Flow at Peak Flow a t Developed Flow Event Southwest Outlet Southwest Outlet North Outle t (cfs) (cfs) (cfs) (cfs) 2 year 5.6 5.5 0.1 5.6 10 year 10.4 10.2 0.1 10.3 25 year 12.5 12.1 0.1 12.2 SO year 14.1 13.7 0.2 13.9 100 year 16.3 15.7 0.2 15.9 Table 2: Pre-Developed and Post-Developed Site Outflow s CONCLUSION Based on visual evidence, engineering drainage calculations and s Gessner Engineering believes that the post-development flows are (10}, twenty-five (25}, fifty (SO}, and one hundred (100} year design and do not create adverse impacts to downstream properties. Work Certification ound engineering judgment, reduced for the two (2}, ten storms for this development, sign was prepared by me in Drainage Guidelines for the "This report for the drainage design of the Brazos Valley Floor & De accordance with the provisions of the Bryan/College Station Unified owners of the property. All licenses and permits required by an regulatory agencies for the proposed drainage improvements have be y and all state and federal en issued." Licensed Professio State of Texas No. nal Engineer 98398 Gessner Engineering ~ 8 APPENDIX A: General Location Map Gessner Engineering 9 Gessner Engineering - 10 APPENDIX B: FEMA 100 Year Floodplain Map Gessner Engineering - 95000 FT BRAZOS COUNTY UN IN CORPORA TED AREAS ributary 10. 481195 Hopes Creek Tributary JO 30° 33' 45" 00 0 MAP SCALE 1" = 1000' 1000 PANEL0310E FLOOD INSURANCE RATE MAP BRAZOS COUNTY, TEXAS AND INCORPORATED AREAS PANEL 310 OF 475 (SEE MAP INDEX FOR FIRM PANEL LAYOUT) ~ ~ BRAZOS COUNTY COLLEGE STATION, CnYOF .a11gs <80083 0310 0310 NoUce to User: The Map Number shown below should be used when placing map orders; the Community Number shown above should be used on Insurance applications for the subject community. MAP NUMBER 48041C0310E MAP REVISED MAY 16, 2012 Federal Emergency Mimagcment Agency This Is an ofllclal copy of a portion of the abolle referenced nooct map. It was extracted using F-MIT On-Line. This map does not renect changes or amendments which may h8"" been made subsequent to the date on the title block. For the latest product information about National Flood Insurance ------------------------------------------------Program nood maps check the FEMA Flood Map Store at www.msc.fema.gov 11 APPENDIXC: Drainage Area Maps and Calculations Gessner Engineering 12 APPEND/XO: Hydrographs - G Subbasin 'PRE -AREA 1" Results for Run "PRE - 2 YEAR" 0.00 0.01 0.02 ~ 0.03 t 0.04 Q) 0 0.05 0.06 I -f--i-----·-+------- ~ ~ 0 w:: 0.07 0.08 6 5 4 3 2 0 00:00 I I I -j I I I I i I I I I 03:00 06:00 Legend (Compute Time: 07Apr2014, 15:22:31) ---- ---~ ! -- I =--;r v I I 09:00 12:00 01Jan2013 15:00 --------------- I I 18:00 13 _j_ I --· ~ I ' I 21 :OO 00:0( I -Run:PRE -2 YEAR Element:PRE -AREA 1 Result:Precipnation -Run: PRE -2 YEAR Element: PRE -AREA 1 Result:Precipnation loss --Run:PRE -2 YEAR Element:PRE -AREA 1 Result:Outflow - - -Run: PRE - 2 YEAR Element: PRE -AREA 1 Result:Baseflow Gessner Engineering G Subbasin "PRE -AREA 1' Results for Run "PRE -10 YEAR" 000 0.02 0.04 '2 c t 0.06 Q) a 0.08 0.10 0.12 12 10 I -, -L • -t _j __ _ .L --_l 8 ------- ~ I ;--i--I --, ~ 6 I ~ ~ 0 u: 4 I 2 -r -+ !- 0 00:00 03:00 06:00 09:00 I L~ (Compute Tl111t!: 07Apr2014, 15:.22:30) -Run:PRE -10 YEAR Element:PRE-AREA 1 Resul:Preclpltation --Run:PRE -10 YEAR Element:PRE -AREA 1 Result:Outflow r - 12:00 01Jan2013 15:00 18:00 21 :00 -Run:PRE -10 YEAR Elemenl:PRE -AREA 1 Resut:Precipltalion Loss - - -Run:PRE -10 YEAR Elemenl:PRE -AREA 1 Resut:Baseflow 00:0( I 14 Gessner Engineering 15 Subbasin "PRE -AREA 1" Results for Run "PRE -25 YEAR" 000 0.02 0.04 ~ 0.06 :5 c. Q) 0.08 0 0.10 0.12 I I -1 -r I ----I I r I I I J -·--1--· 14 12 10 8 ~ ~ 6 0 LL: ------... _J L __ J_ -----<-----:---[ 1_ - . I I I ,__ ---· I 1- I I 4 2 I I I 0 I I I I I I I 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21 :00 00:0( I 01Jan2013 I Legend (Compute Ttme: 07Apr2014, 15:22:31) -Run:PRE -25 YEAR Element:PRE -AREA 1 Result:Precip~mion -Run:PRE -25 YEAR Element:PRE -AREA 1 RestJl:Precipiteilion Loss --Run:PRE -25 YEAR Element:PRE -AREA 1 Result:Outflow - --Run:PRE -25 YEAR Element: PRE -AREA 1 RestJl:Baseflow G Gessner Engineering G la 16 Subbasin "PRE -AREA 1" Results for Run "PRE -50 YEAR" 0.001 ----:-----;-----...... ~ ~~: ---~---_ j I --~-i ----t ________ I -I --t r -~i t-___ - -!---l------+-l --•1_.1__.j_-· ->----II '2 0.06 = ~ 0.08 Q) 0 0.10 0.12 0.14 0.16 16 14 12 10 ~ 8 ~ 0 u: 6 4 2 ____ L _____ J_ [ _J I I I I -1-1 _ _l~ I I -, 01------.-~~===,::::::::::==::::::::::::::==---~---l--=====:=:======±:=========!l 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21:00 00:0( I I Legend {ConµJte Time: 07Apr2014, 15:22:31) -Run:PRE -50 YEAR Element: PRE -AREA 1 Result: Precipitation -Run: PRE -50 YEAR Elemert:PRE -AREA 1 ResUl:Precipltation Loss --Run:PRE -50 YEAR Element:PRE -AREA 1 Resul:Outflow ---Run:PRE -50 YEAR Elemert:PRE -AREA 1 ReslJl:Baseflow Gessner Engineering G 17 Sub basin "PRE -AREA 1" Results for Run "PRE -1 DO YEAR" 0.00 0.02 0.04 0.06 '2 ""'0.08 .s:::: I ~--r t-l T_ --_J -I --·\-------~-!- -+-------;-----------·-g. 0.10 0 0.12 0.14 ···--·----r 0.16 0.18 18 16 14 12 10 E ~ 8 0 u:: 6 !- _ _J_ __ I _J_ ;-----·-. -.J -~ I -_-J _,-_ ------~----,. _----r --· 4 -----+-=-;----! ___ ----·-·--,-~-- -·---1 01-----:...~====::;======:::::C=----l----L----=====:::::====:::±=======:!l 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :00 OO:OC I I Legend {Compure Tllllt!!: 07Apr2014, 15:22:30) -Rt.nPRE -100 YEAR Elemenl:PRE -AREA 1 Result:Precipilation -Rl.11'.PRE -100 YEAR Element: PRE -ARE.A 1 Result: Precipitation loss --Rt.r1:PRE -100 YEAR Element:PRE -AREA 1 Result:Outflow ---Rl.11'.PRE -1 00 YEAR Element: PRE -AREA 1 Result:Baseflow Gessner Engineering G Junction "SOUTWEST OUTLET" Results for Run "POST -2 YEAR" , ,. •' ,. ,, 2 -i--r------·-·iu~\ i' I I ~~ ' ~ 11 ~ -<--+---+--1 1 ---+-~--·-j7_,.__~ ------~~,---, ----+----• •ll "' I .1,r.. t\'\ I fl\\\.\ . I 0 1--~~L-~...-...l=--~~;;;;.~~-~--~·~~j/l~\~.-~~~~~~~-~--~-J~--=~=~~---~~~ .......... ~-~~~~--~--~-~~;;;;;;;~ 18 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :00 OO:OC I I LI!~ (Compute Timi!: l'll\pr2014, 14:36: 29) --Run: POST -2 YEAR Bement:SOUTVl/EST OUTLET Result: Outflow - --Run: POST -2 YEAR Elemenl:REACH-2 Result: Outflow ---- --Run:POST - 2 YEAR Bement: POST -AREA 3 Result: Outflow ---· Run:POST - 2 YEAR Bemenl:REACH-1 Result:Oulflow - ---Run:POST -2 YEAR Bement: POST -AREA 4 Resuft:Out11ow Gessner Engineering G 19 Junction "SOUTWEST OUTLET" Results for Run "POST -10 YEAR" 10 __ 1 -J I -I I I I I B ---· ~-·-~------, I ~ 6 _,__ __ -L ~ ~ 0 u: I " I 4 " ~, !-l~ :: ' . I I . ' I 2 I ol-~~------==~;;:;;;;;;~~~~~~~~~;;;;;~~;;;;:;:;;;t;;;~~~ 00:00 03:00 06:00 09:00 I Leiiend (Compute Time: 1'1Apr2014, 14:36:26) --Run:POST -10 YEAR Element:SOUTV\IEST OUTLET Result:Outflow --- ---Run: POST -10 YEAR Element: POST -AREA 3 RestJt:Outflow ----Run:POST -10 YEAR Element:POST -AREA 4 RestJt:Outflow 12:00 01Jan2013 15:00 1 B:OO 21 :00 ---Rt.n:POST -10 YEAR Elemert:REACH-2 Resut:Outflow ----Run:POST -10 YEAR Elemert:REACH-1 Resut:Outflow 00:0( I Gessner Engineering G Junction "SOUTWEST OUTLET" Results for Run "POST -25 YEAR" 14 ' 12 ' 10 l I 8 I ---j I - J __ --------·---1 ---- I I 4 2 -I I 00:00 03:00 06:00 I Legend (Compute Time: 14Apr2014, 14:36:28) I I I I I I I I I I I I I I _J -------- I I I I " " .. r ~ .. . .. ·~· 1rf \~ 1J '1\ lj •' I )~ ---(_ _ ----f ~ ----------~-~ ----~ ----I : I .~ I :r ~' I ., ' ., \ I :I .\ 1: .. " ..... I .·./'.-'. • ,· •. _ -..... ~-b=:'_--~·~-:-/I '·· -~~:::_~~~~-~- I 09:00 I 12:00 01Jan2013 I I 15:00 18:00 20 I ------- I I I -f-----.. I I I I 21 :OO 00:0( I --Run:POST -25 YEAR Element:SOUlV\IEST OUTLET Resutt:Outflow • -----Run: POST -25 YEAR Element: POST • AREA 3 Resutt:Outflow - --Run: POST -25 YEAR Element:REACH-2 Resutt:Outflow ---· Run:POST -25 YEAR Element:REACH-1 Resutt:Outflow -• --Run: POST -25 YEAR Element: POST -AREA 4 Resutt:Outflow Gessner Engineering G 21 Junction "SOUTWEST OUTLET" Results for Run "POST -50 YEAR" ' I ! I 12----------r ---j ' I ' ' I i ! I i I I 00:00 03:00 06:00 09:00 I Legend (Compute 1ime: 14Apr2014, 14:36:31) --Rm:POST -50 YEAR Element:SOUTVllEST OUTLET Result:Outflow ------Rm: POST -50 YEAR Element: POST -AREA 3 Result: Outflow ----Rm: POST -50 YEAR Element: POST -AREA 4 Result:Outflow 12:00 01Jan2013 I I 15:00 18:00 _,__ ____ - I 21 :OD OO:OC I ---Rm: POST -50 YEAR Element:REACH-2 Result: Outflow ---· Rm:POST -50 YEAR Element:REACH-1 Result:Outflow Gessner Engineering G 14 12-i------+ 10 --- Junction "SOUTWEST OUTLET" Results for Run "POST - 1 DD YEAR" I I -t-- --~ ~ 94-----~----->-------1------1 ~ 6 4 24----. --- 22 J_ -+-- I --r-· I I o J_~--...,.....m=-~~~~~~~:2.J~;;;;_~~~~~~~~;;;;;;;:;;;;;;;::;:;:~ 00:00 03:00 06:00 09:00 I Legend (Compute Trnt!!: 14Apr2014, 14:36:25) --Run:POST -100 YEAR Elemert:SOUl\lllEST OUTLET Resul:Outflow ---- --Run: POST -100 YEAR Elemert:POST -AREA 3 Resuft:Outflow ----Run:POST -100 YEAR Elemert:POST -AREA 4 Result:Outflow 12:00 01Jan2013 15:00 19:00 21 :00 ---Run: POST -100 YEAR Element:REACH-2 Resul:O\iflow - - -· Run: POST -100 YEAR Element:REACH-1 Resut:O\iflow 00:0( I Gessner Engineering 23 APPENDIX E: HEC-HMS Calculations G • PRE-AREA1 Pre-Developed HEC-HMS Model Project: 11-0355 Simulation Run: PRE -2 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Time: 18Mar2014, 11:31:25 Basin Model: 11-0355 PRE Meteorologic Model: 2 YR Control Specifications: Control l Show Elements: [All Elements • j Volume Units: @ IN ()AC-FT Sorting: [Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2,) (CFS) (IN) PRE-AREA 1 0.0037 5.6 01Jan20l3, 12:16 3.19 Project: 11-0355 Simulation Run: PRE-10 YEAR Start of Run: 01Jan20l3, 00:00 End of Run: 03Jan20l3, 00:00 Compute Time: 18Mar2014, 11:32:38 Basin Model: 11-0355 PRE Meteorologic Model: 10 YR Control Specifications: Control 1 Show Elements: [All Elements .... j Volume Units: @ IN 0 AC-FT Sorting: !Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) (CFS) (lN) PRE -AREA 1 0.0037 10.4 01Jan2013, 12: 16 6.07 Project: 11-0355 Simulation Run: PRE -25 YEAR Start of Run: 01Jan20l3, 00:00 End of Run: 03Jan20l3,. 00:00 Compute Time: 18Mar2014, 11:32:58 Basin Model: 11-0355 PRE Meteorologic Model: 25 YR Control Specifications: Control 1 Sho1N Elements: [All .Elements ... 1 Volume Units: @ IN 0 AC-FT Sorting: [Hydrologic ... J Hydrologic Drainage Area Peak .Discharge Time of Peak Volume Bement (MI2) (CFS} (IN) PRE -AREA 1 0.0037 12.5 01Jan2013, 12:16 7.34 24 Gessner Engineering G Project:. 11-0355 Simulation Run: PRE -50 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:.00 Compute Time : 18Mar2014, 11:34:27 Basin Model: 11-0355 PRE Meteorologic Model: SO YR Control Specifications: Control 1 Show Elements: !Aii Elements .... J Volume Units: @ IN C) AC-FT Sorting: [Hydrologic ... J Hydrologic Element PRE -AREA 1 Drainage Area (MI2) 0.0037 Project: 11-0355 Peak Discharge Ttme of Peak (CFS) 14.1 01Jan2013 12:16 Simulation Run: PRE -100 YEAR. Volume (IN) 8.32 Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Ttme: 18Mar2014, 11:34:45 Basin Model:. 11-0355 PRE Meteorologic Model: 100 YR Control Specifications: Control 1 Show Elements: [All Elements .... J Volume Units: ~ IN 0 AC-FT Sorting: [Hydrologic .... J Hydrologic Element PRE-AREA 1 Drainage Area (MI2) 0.0037 Peak Discharge Time of Peak Volume (CFS) (IN) 16.3 01Jan2013, 12:16 9.70 --~-----1 25 Gessner Engineering 26 I POST -AREA 1 G, POST-AREA 2 G, POST -AREA 5 Q I POST -AREA 4 Post-Developed HEC-HMS Model G Gessner Engineering G Project: 11-0355 Simulation Run: POST -2 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute lime: 14Apr2014, 14:36:29 Basin Model: 11-035 5 POST Meteorologic Model: 2 YR Control Specifications: Control 1 Show 8ements: I All Elements .... j Volume Units: ~ IN ()AC-FT Sorting: [ Hydrologic .... J Hydrologic Drainage Area Peak Discharge lime of Peak Volume Bement (MI2) {CFS) (IN) POST-AREA 5 0.0010470 2.2 01Jan2013, 12:08 3.52 POND2 0.0010470 1.0 01Jan2013, 12:24 3.52 Reach-2 0.0010470 1.0 01Jan2013, 12:24 3.52 POST-AREA 3 0.0013750 2.4 01Jan2013, 12: 13 3.51 POST-AREA 6 .000953 2.1 01Jan2013, 12:09 3.91 POND 1 .000953 1.7 01Jan2013, 12:14 3.91 Reach-1 .000953 1.7 01Jan2013, 12: 15 3.91 POST -AREA 4 .000328 0.6 01Jan2013, 12:08 2 .. 95 SOLJTWEST Ol.JTLET 0.0037030 5.5 01Jan2013, 12:14 3.57 POST-AREA 2 .00001733 0.0 01Jan2013, 12:07 4.26 POST -AREA 1 .00001679 0.0 01Jan2013, 12:07 4.26 NORlH Ol.JTLET .00003412 0.1 01Jan2013, 12:07 4.26 Project: 11-0355 Simulation Run: POST -10 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute lime: 14Apr2014, 14:36:26 Basin Model: 11-0355 POST Meteorologic Model: 10 YR Control Specifications: Control 1 Show 8ements: [All Elements .... J Volume Units: i IN ~ AC-FT Sorting: [Hydrologic .... ] Hydrologic Element POST-AREAS POND2 Reach-2 POST-AREA3 POST -AREA. 6 POND 1 Reach-1 POST-AREA4 SOUTVIEST Ol.JTLET POST-AREA 2 POST-AREA 1 NORlH Ol.JTLET Drainage Area (MI2} 0.0010470 0.0010470 0.0010470 0.0013750 .000953 .000953 .000953 .000328 0.0037030 .00001733 .00001679 .00003412 Peak Discharge lime of Peak Volume (CFS) (IN) 3.9 01Jan2013, 12:08 6.46 1.9 01Jan2013, 12:22 6.46 1.9 01Jan2013, 12:22 6.46 4.3 O 1Jan2013, 12: 13 6.44 3.5 01Jan2013, 12:09 6.88 3.2 01Jan2013, 12:13 6.88 3.2 01Jan2013, 12:14 6.88 1.2 01Jan2013, 12:07 5.78 10.2 01Jan2013, 12:13 6.50 0.1 01Jan2013, 12:07 7.25 0.1 01Jan2013, 12:07 7.25 0.1 01Jan2013, 12:07 7.25 27 Gessner Engineering G Project: 11-0355' Simulation Run : POST -25 YEAR Start of Run: 01Jan2013 00:00 End of Run: 02Jan2013, 00:02 Compute lime: 14Apr2014, 14:36:28 Basin Model: 1Hl355 POST Meteorologic Model: 25 YR Control Specifications: Control ! 28 Show Elements,: I All Elements .... J Volume Units: @ IN () AC~ Sorting: [ Hydrologic ... J Hydrologic Drainage Area Peak Discharge lime of Peak Volume Element (Ml2) {CFS) (IN) POST-AREA 5 0.0010470 4.6 01Jan20H, 12:08 7.74 POND 2 0.0010470 .2.3 01Jan2013, 12:21 7.74 Reach-2 0.0010470 2.3 01Jan2013, 12:21 7.74 POST-AREA 3 0.0013750 -5.1 01Jan2013, 12:13 7.72 POST-AREA6 .000953 4.2 01Jan2013, 12:09 8.18 POND 1 .000953 3.8 01Jan2013, 12:12 8.18 Reach-1 .000953 3.8 01Jan2013, 12:13 8.17 POST -AREA 4 .0003.28 1.4 01Jan201J., 12:07 7.04 SOLJTVIJEST OUTLET 0.0037030 12.1 01Jan20 n , 12: 13 7.78 POST-AREA 2 .00001733 0.1 01Jan2013, 12:07 8.55 POST-AREA 1 .00001679 0.1 01Jan201J., 12:07 8.55 NORTH OUTLET .00003412 0.2 01Jan201J., 12:07 8.55 Project: 11-0355 Simulation Run: POST -50 YEAR Start ofRun: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute lime: 14Apr2014, 14:36:31 Basin Model: 11-0355 POST Meteorologic Model: 50 YR Control Specifications: Control 1 Show Elements: I All Elements ..,., ] Volume Units: @ IN (:J AC~ Hydrologic Element Drainage Area Peak Discharge lime of Peak (MI2) (CFS) POST -AREA 5 0.0010470 5.2 01Jan2013, 12:08 POND 2 0.0010470 2.6 01Jan2013, 12:21 Reach-2 0.0010470 2.6 01Jan2013, 12:21 POST -AREA 3 0.0013750 5.8 01Jan2013, 12:13 POST-AREA 6 .000953 4.6 01Jan2013, 12:09 POND 1 .000953 4.3 01Jan2013, 12:12 Reach-1 .000953 4.3 01Jan2013, 12: 13 POST-AREA 4 .0003.28 l .6 01Jan2013, 12:07 SOlfTWEST OUTLET 0.0037030 13.7 01Jan2013, 12:13 POST-AREA 2 .00001733 0.1 01Jan2013, 12:07 POST -AREA 1 .00001679 0.1 01Jan2013, 12:07 NORTH OUTLET .00003412 0.2 01Jan2013, 12:07 Volume (IN) 8.73 8.73 8.71 9.17 9.17 9.17 8.01 8.77 9.55 9.55 9.55 Gessner Engineering G Project: 11-0355 Simulation Run: POST -100 YEAR Start of Run: 01Jan2013, 00 :00 End of Run: 02Jan2013, 00:02 Compute lime: 14Apr2014, .14:36:25 Basin Model: 11-0355 POST Meteorologic Model: 100 YR Control Specifications: Control 1 29 Show Elements: I All Elements ... j Volume Units: @ IN O AC-FT Sorting: ! Hydrologic ... ] Hydrologic Drainage Area Element (MI2) POST -.AREA 5 0.0010470 POND2 0.0010470 Reach-2 0.0010470 POST-AREA3 0.0013750 POST-AREA6 .000953 POND 1 .000953 Reach-1 .000953 POST -AREA4 .000328 SOUT\~JEST OUTLET 0.0037030 POST-AREA2 .00001733 POST-AREA 1 .00001679 NOR1H OLJTlET .00003412 Peak Discharge Time of Peak (CFS) 6.0 01Jan2013, 12:08 3.0 01Jan2013, 12:21 3.0 01Jan2013, .12:21 6.6 01Jan2013, .12:13 5.3 01Jan2013, .12:09 4. 9 O 1Jan2013, .12: 12 4. 9 01Jan2013, .12: 13 1.8 01Jan2013, .12:07 15.7 01Jan2013, .12: 13 0.1 01Jan2013, .12:07 0.1 01Jan2013, 12:07 0.2 01Jan2013, 12:07 Volum.e (IN) 10.12 l0.12 10.12 10.10 l0.57 l0.57 10.56 9.38 10.16 10.95 10.95 l0.95 Gessner Engineering 30 APPENDIX F: Technical Design Summary Gessner Engineering SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) Engineering and Design Professionals Information Engineering Firm Name and Address: Jurisdiction Gessner Engineering City: Bryan 2501 Ashford Drive Suite 102 x College Station College Station, TX 77840 Date of Submittal: Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: Jeremy N. Peters, 979 -680 -8840, jpeters@gessnerengineering.com Supporting Engineering I Consulting Firm(s): Other contacts: Developer I Owner I Applicant Information Developer I Applicant Name and Address: Phone and e-mail: Chuck Moreau -Moreau Family Investments, Ltd. 764-4084 1834 Harris Drive chuck@bvcarpetoutlet.com College Station, TX 77845 Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: Project Identification Development Name: Brazos Valley Floor and Design Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? Site Project If multi-phase, subject property is phase of Legal description of subject property (phase) or Project Area: (see Section II , Paragraph B-3a) Lot 10, Block 1, Rock Prairie West Business Park If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. General Location of Project Area, or subject property (phase): Rock Prairie & Wellborn In City Limits? Bryan: acres. College Station: 2.38 acres. STORMWATER DESIGN GUIDELINES Effective February 2007 Extraterritorial Jurisdiction (acreage): Bryan: College Station: Acreage Outside ET J: Page 3 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: N. Graham Rd ., Old Wellborn Rd. Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): Plat Information For Project or Subject Property (or Phase) Preliminary Plat File#: Final Plat File #: Date: Name: Status and Vol/Pg: If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: PPD KX~)iAIJ or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Preliminary Report Required? No Submittal Date Review Date Review Comments Addressed? Yes --No --In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordination Dept. Contact: Date: Subject: With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? Yes No X -- Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No x -- -- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): T AMUS Needed? Yes No x ---- Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective in spaces below. Entity Permitted or Approved? US Army Crops of Engineers No x Yes --- US Environmental Protection Agency No x Yes --- Texas Commission on Environmental Quality No x Yes ---- Brazos River Authority No x Yes --- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 Status of Actions (include dates) APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Site _X_ Redevelopment of one platted lot, or two or more adjoining platted lots. Development __ Building on a sing le platted lot of undeveloped land. Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ Construction of streets and utilities to serve one or more platted lots. Development __ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of Construction of new parking lot for existing building and construction of new Pro~osed 12,000 SF warehouse Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No Yes ---- FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I No _X __ Yes __ (Section 11, Paragraph B 1) or a tributary thereof? Is any part of subject property in floodplain I No _X_ Yes Rate Map area of a FEMA-regulated watercourse? -- Encroachment( s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No x -- Yes -- If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro1:1ert~ Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (&date) here, and attach copy if not already in City files. -- Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi-phase project, describe stormwater management x plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? _X __ No --Yes Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? _X_ No --Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) _X __ Detention is required. --Need must be evaluated. __ Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? x No Yes If yes, --describe splits below. In Part 4 describe desiqn concept for handlinq this. Watershed or Basin Larger acreage Lesser acreage Above-Project Areas(Section II , Paragraph 83-a) Does Project Area (project or phase) receive runoff from upland areas? _X_ No --Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? --No --Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? x No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Property Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage easements exist for any part of pathway(s)? X No Yes If yes, for what part of length? % Created by? __ plat, or instrument. If instrument(s), describe their provisions. Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Pathway Areas Nearby Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Detention pond on adjacent property. Drainage 1--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-1 Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? _x_ No __ Yes If yes, explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features wi ll be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No Yes Separate Instrument? x No Yes ---- Per Guidelines reference above, how will __ Establishing Easements (Scenario 1) runoff be discharged to neighboring _x_ Pre-development Release (Scenario 2) property(ies )? Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# ) Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) detention Com bi nation: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? No --Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters J Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result in shifting runoff between Basins or Identify gaining Basins or Watersheds and acres shifting: !----------------------------~ between Watersheds? X No Yes What design and mitigation is used to compensate for increased runoff from gaining basin or watershed? How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 1. __ With facility(ies) involving other development projects. 2. _x __ Establishing features to serve overall Project Area. 3. __ On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit# ) Two detention ponds; one located to the southwest of the proposed building and one to the northwest of the building. 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? _x___ No project(s)? __ Yes In which phase(s) or Are other Best Management Practices for reducing stormwater pollutants proposed? _x_ No __ Yes Summarize type of BMP and extent of use: If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. Detention elements Conduit elements Channel features __ Swales __ Ditches __ Inlets __ Valley gutters __ Outfalls Other __ Culvert features __ Bridges -------- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No _X __ Yes Identify type and general size and In which phase(s). Culvert under drives at NW and SW of the Proposed Building. If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): Property is served by two detention ponds ; one to the NW and one to the SW of the proposed building. Both ponds discharge to SW of site. Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? __ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? I Surfaces? C'-· l:l (lJ (/) Steepest side slopes: Usual front slopes: Usual back slopes: (/) ::J (lJ (/) >- (lJ I ..c Flow line slopes: least Typical distance from travelway: ~ l:l typical (Attached Exhibit# ) (lJ 0 greatest :Q (/) z 1 x I Are longitudinal culvert ends in compliance with B-CS Standard Specifications? ~ Yes No, then explain: -< (/) At intersections or otherwise, do valley gutters cross arterial or collector streets? .0 (lJ No Yes If yes explain: ~ C'-· >--- Ul:l I ..c (lJ ..... (/) ·-::J s: ~ Are valley gutters proposed to cross any street away from an intersection? (/) (lJ a;~ 0 No Yes Explain: (number of locations?) ~ OlZ ---- 1n l:l I (lJ c ~ co -< x STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? --Yes --No If "no", identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? --Yes --No If no, explain where and why not. C'-· "O Q) (/) Will inlet size and placement prevent exceeding allowable water spread for 10-year ~ L.. design storm throughout site (or phase)? Yes No If no, explain. 2 -----~ Ol -o-c "O ro Q) Sag curves: Are inlets placed at low points? Yes No Are inlets and .0 ~ ---- L.. ·-conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? ~-0 c Yes No Explain "no" answers. ..c. 8 ---- :t= -~ B Q) Q) L.. -(/) Q) Will 100-yr stormflow be contained in combination of ROW and buried conduit on L.. <( whole length of all streets? Yes No If no, describe where and why. ---- Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes --No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? __ No --Yes Identify length(s) and where used. C'-· "O Pipe runs between system I Typical Q) (/) Longest (/) Q) access points (feet): ~ >- ii Are junction boxes used at each bend? --Yes --No If not, explain where and why. (/) c ·-0 ~z i xl Are downstream soffits at or below upstream soffits? Least amount that hydraulic (/) grade line is below gutter line .!!l. Yes No __ If not, explain where and why: --(system-wide): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) -(/) (!l (..) c co 1ii c (!l L... -o ~ E ::::i L... .~ .2 c . 0 .2 ~-~ E <llE (!l ..... co (/) (/) ~(!l c :2 ·-> ~ e 1:J a. § 05 .8 ~ Cf) (/) (!l (ii L... co a. (!l (/) Describe watercourse(s), or system(s) receiving system discharge(s) below (include design discharge velocity, and angle between converging flow lines). 1) Watercourse (or system), velocity, and angle? 2) Watercourse (or system), velocity, and angle? 3) Watercourse (or system), velocity, and angle? For each outfall above, what measures are taken to prevent erosion or scour of receiving and all facilities at juncture? 1) 2) c ~ 3) Are swale(s) situated along property lines between properties? __ No __ Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): Flow line slopes (minimum and maximum): Outfall characteristics for each (velocity, convergent angle, & end treatment). Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? __ Yes __ No If "no" explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters / Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? _x_ No __ Yes If so, provide the following: en Q) Is 25-year flow contained with 6 inches offreeboard throughout? __ Yes No ..c -- .B Are top of banks separated from road shoulders 2 feet or more? __ Yes No 0 -- Q) Are all ditch sections trapezoidal and at least 1.5 feet deep? --Yes --No :Q For any "no" answers provide location(s) and explain: en -0 cu 0 0::: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: en Q) Is 100-year design flow contained in conduit/swale combination? >-Yes No ---- lw If "no" explain: c Space for 100-year storm flow? ROW Easement Width 0 cu z (i) Swale Surface type, minimum Conduit Type and size, minimum and maximum 1 ~ and maximum slopes: slopes, design storm: 0 C'· ~ El -0 Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Q) cu c >-c cu c ..c cu 0 L... c .2 Q) c Access Describe how maintenance access is provided (to swale, into conduit): Cl.. 0 0 :;:; -cu 0 E ::::J L... .~ 0 -c c Instance 2 Describe general location, approximate length: Q) -0 E Q) cu en en ::::J en Q) Is 100-year design flow contained in conduit/swale combination? Yes No c -0 ·;;: ----0 If "no" explain: ~ 0 L... c Cl.. :.0 Q) Space for 100-year storm flow? ROW Easement Width E Q) 0 ..c 0 en Swale Surface type, minimum Conduit Type and size, minimum and maximum ..... Q) ::::J ..... and maximum slopes: slopes, design storm: cu -0 L... c cu 0 Cl.. 0 Q) Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): --en Q) co c ~ _£_ en Q) Access Describe how maintenance access is provided (to swale, into conduit): L... <{ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Si te) (continued) If "yes" provide the following information for each instance: Instance 1 Descri be general location, approximate length, surfacing: c "Cu E a. x 0 w L.. '+- :i:: ui Is 100-year design flow contained in swale? --Yes --No Is swale wholly 0 Q) within drainage ROW? Yes No Explain "no" answers: c ,_I ::::J -- -- L.. Q) > 'iii Access Describe how mai nte nance access is provide: (.) Q) L.. 0 ..... z ::::J -0 I c 0 (.) Instance 2 Describe general location, approximate length, surfacing: -0 Q) ·;:: C'-· ::::J (/) ..c c :5 Q) 0 E £ Q) (/) Is 100-year design flow contained in swale? Yes No Is swale wholl y -~ ro ----Q) within drainage ROW? __ Yes No Explain "no" answers: (/) L.. --Q) 0 co 5: 3: (/) 0 ~ a: Access Describe how maintenance access is provided: (.) -..c ::::J a. Instance 3, 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, wid ened, or straightened) or otherwi se altered? --No --Yes If only slightly shaped, see "Swales" in this Part . If creating side banks, provide inform ation below. C'-· -0 c Will design repl icate natural channel? Yes No If "no", for each instance Q) ----(/) ro describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year 0 a. a. x design flow, and amount of freeboard : 0 w L.. a. Instance 1: (/) (/) c Q) Q) >- E I Q) > Instance 2: 0 L.. a. E 0 ·-z (ii xi c Instance 3: c ro ..c u STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? x No Yes ----If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? _x_ Yes No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow . ........ -0 Cl) :::J c ~ Watercourses (and tributaries): Aside from fringe changes, are Regulatory 0 Watercourses proposed to be altered? _x_ No __ Yes Explain below. ~ (/) c Submit full report describing proposed changes to Regulatory Watercourses. Address Cl) existing and proposed section size and shape, surfaces, alignment, flow line changes, E Cl) length affected, and capacity, and provide full documentation of analysis procedures > 0 and data . Is full report submitted? Yes No If "no" explain: .... --a. E - Qi c c ro All Proposed Channel Work: For all proposed channel work, provide information .s:: u requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? --Yes --No If not, identify location and explain: Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? 2 For each provide info. below. For each dry-type facilitiy: Facility 1 POND 1 Facility 2PQND 2 Acres served & design volume + 10% 0.61 ac 0.061 ac-ft 0.67 ac 0.165 ac-ft 100-yr volume: free flow & plugged 0.028ac-ft 0.055 ac-ft 0.61 0.15 ac-ft Design discharge (10 yr & 25 yr) 3.2 cfs 3.8 cfs 1.9 cfs 2.3 cfs Spillway crest at 100-yr WSE? _x_yes --no _x _yes --no Berms 6 inches above plugged WSE? _x_yes --no _x __ yes --no Explain any "no" answers: en Q) >- 1 For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: 3.8 cfs 0 z Facility 2: 2.3 cfs I Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: _x_Yes No Facility 2: x Yes No -- ----C'-· If "no" explain: -0 Q) en 0 a. 0 L.. 0.... For each, what is velocity of 25-yr design discharge at outlet? & at spillway? en Q) Facility 1: & 4.75 ft/sec Facility 2: 13.22 ft/sec & 4.38 ft/sec ~ -Are energy dissipation measures used? No -2L.. Yes Describe type and "[) cu -- LL location: c Riprap at discharge points 0 ~ Q) -Q) 0 Q) For each, is spillway surface treatment other than concrete? Yes or no, and describe: L.. <( Facility 1: no, concrete weir Facility 2: no, concrete weir For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Riprap Facility 2: Riprap If berms are used give heights, slopes and surface treatments of sides. Facility 1: Pond 1: no berms, grass side slopes 10%-25% Pond 2: berm on plan north and west sides, 1.2' max. berm height, Facility 2: grass side slopes 16%-23% STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": en Facility 1; yes <ll ~ == £" ~ <ll Facility 2: yes LL ::J c c:;:::: 0 c ~ 0 c (.) <ll~ Q) For additional facilities provide all same information on a separate sheet. 0 Are parking areas to be used for detention? _x_ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? No x Yes If "yes", provide information in next two boxes. -- -- Will 25-yr. flow pass without flowing over driveway in all cases? x Yes No ---- Without causing flowing or standing water on public roadway? x Yes No ---- Designs & materials comply with B-CS Technical Specifications? _X_ Yes --No Explain any "no" answers: C'-· en Ol c en Are culverts parallel to public roadway alignment? x Yes No Explain: en 0 -- --..... en (.) <ll 2 >-.~ I o..x Creeks at Private Drives: Do private driveways, drives, or streets cross drainage -ways that serve Above-Project areas or are in public easements/ ROW? cu "tJ 0 x No Yes If "yes" provide information below. <ll z ----en I ::J How many instances? Describe location and provide information below. en t <ll Location 1: 2= ::J (.) <ll Location 2: ..... <( Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulato!)l Watercourses (&Tributaries}: Are culv erts proposed on these facilities? x No __ Yes, then provide full report documenting assumptions, --criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: -Arterial or Major Collector Streets: Will culverts serve these types of roadways? Ci) Q) x No Yes How many instances? For each identify the .i= (/) ---- Q) location and provide the information below. (/) -ro Instance 1: Q) '->-~ I ~ Instance 2: Instance 3: c 0 o~ Yes or No for the 100-year design flow: 1 2 3 z E xi! Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E C-· C1l Is velocity limited per conditions (Table C-11 )? (/) (/) g>-a Explain any "no" answer(s): ·-c ~ C1l 0 c '-0 (.) ·->--ro C1l (.) :;:: .2 -a Q) C1l .0 Minor Collector or Local Streets: Will culverts serve these types of streets? 0 ·-'-'- (.) (.) x No Yes How many instances? for each identify the ·-(/) -Q) -- ---§l -a location and provide the information below: o._ Q) _o.. C1l .;::-Instance 1: -a >. Instance 2: Q) c ~ C1l '+-Instance 3: (/) 0 t (/) Q) Q) For each instance enter value, or "yes" I "no" for: ~ (.) 1 2 3 :J c (.) C1l Design yr. headwater WSE 1 ft. below curb top? Q) U5 '-c <( ·-100-yr. max. depth at street crown 2 feet or less? Q) '-0 Prod uct of velocity (fps) & depth at crown (ft) = ? E '-g Is velocity limited per conditions (Table C-11 )? Limit of down stream analysis (feet)? Explai n any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4-Drainage Conce~t and Design Parameters I Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? Yes No If not, ----identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? --No --Yes If yes, identify location(s) and provide justification: ~ Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? "O No Yes If "yes" identify location(s), describe outfall design treatment(s): (I) ----::::l c ~ 0 ~ CJ) t: (I) Is scour/erosion protection provided to ensure long term stability of culvert structural .2: ::::l components, and surfacing at culvert ends? Yes No If "no" Identify u ----locations and provide justification(s): Will 100-yrflow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? __ Yes --No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? _x_ No --Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? ~ en Q) Ol "O ·;::: co A full report supporting all aspects of the proposed bridge(s) (structural , geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: £ Pollution Prevention construction entrance, erosion control silt fence, hay bales at co Plan (SW3P) pond discharge points ::::J a established for .... project construction? aJ cu x :s: No Yes ---- Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? x No Yes If "yes" list general type and location below. ---- Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? STORMWATER DESIGN GUIDELINES Effective February 2007 Yes -- -- Page 22 of 26 No If "no" explain : APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 • SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4-Drainage Conce~t and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements Channel features ---- Culvert features Swales Ditches Inlets Outfalls ---------- __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology Yes No Is a map(s) showing all Design Drainage Areas provided? _x __ -- Briefly summarize the range of applications made of the Rational Formula: N/A. Rational Method can not be used for detention design per BCS Std. Design Guidelines. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? acres STORMWATER DESIGN GUIDELINES Effective February 2007 Location (or identifier): Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceRt and Design Parameters I Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? 100 No x Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? __ X_ No __ Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall 2, 10, 25, 50, & 100 100 Detention facilities: outlet and conveyance structure(s) 2, 10, 25, 50, & 100 2,10,25,50,&100 Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Roughness coefficients used: For conduit type(s) STORMWATER DESIGN GUIDELINES Effective February 2007 Gutters Conduit Culverts Swales Channels Provide the summary information outlined below: For street gutters: Page 24 of 26 Coefficients: APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? No Yes Head and friction losses No Yes -------- Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? --Yes --No Are elevation drops provided at inlets, manholes, and junction boxes? --Yes --No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? --Yes --No For 100-year flow conditions? --Yes --No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? __ Yes __ No If "no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Effective February 2007 Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher Part 5 -Plans and S~ecifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signing and sealing below. "This report (plan) for the drainage design of the development named in Part B was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued or fall under applicable general permi~"""'''''' --Of ·TE~ \\ ~ (AffixSealJ /~'\,~*· .. :f.r 11 . ~ ~~··· ···.• ., _i I •. * l' I•: ....... : .... 1. l « • •·••••·•••• QM~S \l Licensed Professional Engineer State of Texas PE No. 98398 STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of 26 -. ····· f.••• ••• 'SSA P 'TH • .... "/.· l MEL\ •••• ; •••••••••• : l ~····~:··"gs398 l•I ' ~· ~ •• ..,, ti' t,_ ~· .. ~!CEtl~·~:~ ;'_ \ '\\\~SIOM~\.:·~\ \ \ APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 May 29, 2014 Gessner Engineering Job No. 11-0355 Prepared for: Moreau Family Investments, Ltd. Mr. Chuck Moreau In Accordance with: Unified Stormwater Design Guidelines City of Bryan/City of College Station Prepared by: GESSNER ENGINEERING, LLC College Station, Texas DRAINAGE DESIGN REPORT Brazos Valley Floor and Design College Station, Texas G May 29, 2014 Mr. Alan Gibbs, P.E. City Engineer City of College Station 1101 Texas Avenue College Station, TX 77840 Re: Storm Water Drainage Study Brazos Valley Floor and Design 12900 Old Wellborn Road College Station, Texas Gessner Engineering Job No.: 11-0355 Dear Mr. Gibbs, 2 This report conveys the results of the storm water drainage study conducted by Gessner Engineering for the proposed redevelopment of Brazos Valley Floor and Design, College Station, Texas . Gessner Engineering believes that all information contained in this report is valid. Please contact us if you have any questions or if we can be of further assistance. This report for the drainage design for Brazos Valley Floor and Design was prepared by Gessner Engineering in accordance with provisions of the Bryan/College Station Unified Stormwater Design Guidelines for the owner of the property. Sincerely, GESSNER ENGINEERING LLC, F-7451 Melissa P. Thomas, P.E. Joshua B. Van Wie, E.l.T., M.S. ,...,...,.,,,"' --tOF r~ \\ ..:-~ ~··········:::t~ " .;" ~ ... * ·~.,. .. t;t ............ ~f i:~('Jf l M6LISsA P. THOMAS -, ~·······························.,, I. \ 98398 .~J 'i?><i;;-.. ~fCEM$t.~.··~J' ,, ~.,,, ........ ~ - \\ .. 10ff A\. _..:-' ,,, ...... G 3 TABLE OF CONTENTS EXECUTIVE SUMMARY ........................................................................................................................... 4 INTRODUCTION ...................................................................................................................................... 4 CALCULATIONS ....................................................................................................................................... 5 Time of Concentration ................................................................................................................. 5 Unit Hydrograph .......................................................................................................................... 6 Reach Routing .............................................................................................................................. 6 Peak Runoff Flow ......................................................................................................................... 6 Peak Post-Developed Runoff Flow ............................................................................................... 7 CONCLUSION .......................................................................................................................................... 7 APPENDIX Appendix A: General Location Map Appendix B: FEMA 100 Year Floodplain Map Appendix C: Drainage Area Map and Calculations Appendix D: Hydrographs Appendix E: HEC-HMS Calculations Appendix F: Technical Design Summary Gessner Engineering G • 4 EXECUTIVE SUMMARY This storm water drainage report is submitted to the City of College Station, Texas for review on April 2, 2014 by Melissa P. Thomas, P.E. of Gessner Engineering, located at 2501 Ashford Drive, Suite 102, College Station, Texas 77840. The proposed project consists of the demolition of the asphalt pavement serving the current building and construction of a 15,000 square foot (SF} warehouse and associated new concrete parking. The site will be served by two detention ponds in series. The total area of construction is approximately 2.38 acres. The subject site currently contains a 2,434 SF retail building to remain, a 1,963 sf metal canopy, a 1,112 sf metal awning, and a 24,631 SF of existing parking lot and hardscape all to be removed. The site is located directly northwest of the intersection of Old Wellborn Road and N. Graham Road . The site is located in the Hopes Creek watershed. The site is not located in the FEMA 100 year flood plain, as shown by FIRM number 48041C0310E. This firmette is included as Appendix B. Runoff from the overall drainage area generally flows south until reaching N. Graham Road. Water then flows southwest through a small drainage ditch along N. Graham Road until reaching a tributary of Hopes Creek. Runoff from the subject site reaches N. Graham Road by sheet flow and shallow concentrated flow through a small channel in the center of the property. Runoff from the Carpet Outlet site is stored in a detention pond in the southern corner of the property and discharged to flow across the property to the southwest of both lots until reaching N. Graham Road. Under existing conditions, the total flow exiting the lot and reaching the drainage ditch on N. Graham Road is 16.3 cubic feet per second (cfs) at the peak of the 100 year, Type Ill, 24 hour storm event. After development, runoff will be stored in a series of two detention ponds on the subject property and discharged at the southern corner of the property directly into the ditch along N. Graham Road . Under proposed conditions the flow into the drainage ditch is 15.7 cfs, at the same storm event. Additionally, a small portion of the two driveways along the north property line discharges 0.2 cfs onto the existing Brazos Valley Floor and Design site at the same storm event. The total peak flow of the subject tract under the proposed conditions is 15.9 cfs. The post-developed peak flow is below the pre-developed peak at the 100 year storm event and does not create any issues for downstream properties. INTRODUCTION This storm water drainage report is intended to determine the required detention to match pre- developed storm runoff conditions for the proposed Brazos Valley Floor and Design. The entire Gessner Engineering G 5 drainage area contributes to the drainage ditch along N. Graham Road. The point of contribution to the ditch was used for both pre-developed and post-developed conditions analysis. Drainage Calculations for this site were prepared according to the National Resource Conservation Method as detailed in Technical Release SS (TR-SS) published in June of 1986. Proposed improvements include a 1S,OOO SF building and S0,130 SF concrete pavement and approximately 8,140 SF of detention area. Curve numbers from TR -SS were used based on developed uses as described above. Pre -developed flows were calcu lated based on the existing development for the subject site and based on undeveloped conditions for the Carpet Outlet tract. The calculated pre- developed and developed flows include the two (2), five (S), ten (10), twenty-five (2S), fifty (SO) and one-hundred (100) year storms in accordance with the Bryan/College Station Unified Stormwater Design Guidelines. CALCULATIONS Calculations were performed according to the USDA TR-SS and with the aid of HEC-HMS 3.5 by the U.S. Army Corps of Engineers. The output data from HEC-HMS has been provided as Appendix E. Time of Concentration The time of concentration (travel time) for each drainage area was estimated by summing the flow time for each segment of travel. For sheet flow, travel time was estimated by Manning's Kinematic equation: 0.007 x (nL )°"8 t =-----{ so.4 JP; Where: tt = travel time (hours) n = manning's roughness coefficient L = flow length (feet) s = slope (ft/ft) P2 = 2-year, 24 hour rainfall (inches) For shallow concentrated flow, the travel time was calculated from the flow ve locity based on the slope in the direction of flow. These velocities were taken from Table C-4 of the Bryan College Station Unified Stormwater Design Guidelines. Gessner Engineering G 6 The computed times of concentration for each drainage area are included in Appendix E. Computed values were increased to a minimum time of six (6} minutes as required, based on Chapter 3 of TR-SS which limits the minimum Time of Concentration to 0.1 hour or six (6} minutes. Unit Hydrograph A generic unit hydrograph was computed by distributing the rainfall depths (Table 1} according to the distribution factors for the NCRS Type Ill 24 hour storm. This hydrograph was then applied to each subarea based on the curve number and time of concentration of that area. Reach Routing Hydrographs were routed from subareas to the outflow through the kinematic wave method. This method allows for hydrographs to be translating with time, but not attenuating. The effects of backwater flow and pressure flow in channels were neglected. Peak Runoff Flow Peak Runoff Flow from the site was determined based on the Type Ill 24 hour storm applied to each drainage area. The depth-duration-intervals for each frequency are included in Table 1 below, and were obtained from Table C-6 in the Unified Stormwater Design Guidelines. Curve Number values (CN} were determined from Table C-7, Appendix C of the Unified Stormwater Design Guidelines. Peak pre-developed flows for the subject site adjacent to N. Graham Road are included in Table 1. Drainage areas and calculations are included on sheet CS.O and CS.1, which are attached in Appendix C. Rainfall Depth (in), 24-hr Pre-Developed Peak Flow Frequency duration (cfs) 2 year 4.50 5.6 10 year 7.40 10.4 25 year 8.40 12.5 50 year 9.80 14.1 100 year 11.00 16.3 Table 1: Rainfall Depths and Resulting Flows Peak Post-Developed Runoff Flow The post-developed peak flows compared to the pre-developed peak flows are shown in Table 2 below for each storm event. Hydrographs for each storm event are included as Appendix D. Gessner Engineering G 7 Pre-Developed Post-Developed Post-Developed Total Post- Storm Peak Flow at Peak Flow at Peak Flow at Developed Flow Event Southwest Outlet Southwest Outlet North Outlet (cfs) (cfs) (cfs) (cfs) 2 year 5.6 5.5 0.1 5.6 10 year 10.4 10.2 0.1 10.3 25 year 12.5 12.1 0.1 12.2 SO year 14.1 13.7 0.2 13.9 100 year 16.3 15.7 0.2 15.9 Table 2: Pre-Developed and Post-Developed Site Outflows CONCLUSION Based on visual evidence, engineering drainage calculations and sound engineering judgment, Gessner Engineering believes that the post-development flows are reduced for the two (2}, ten (10}, twenty-five (25), fifty (SO}, and one hundred (100) year design storms for this development, and do not create adverse impacts to downstream properties. Work Certification "This report for the drainage design of the Brazos Valley Floor & Design was prepared by me in accordance with the provisions of the Bryan/College Station Unified Drainage Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued." _,,,,,,, --~OFT \\ .,::. .... '\ .......... f.t~ ,, --, ..... ~··· . _, ~...-~~ ·· .. ~ ' f ;.t ............ ;?1?.~~r t.~~~~~~.~· .. !~?.~~.j r. • • ' ,, ~\ 9839-8 .. ·~" t · ... '-IC ~ ••• ,,f t, ·~· .. EM~~~ .... ' "'""& ••• ••••• l:.~~ _, ,,,10N~\. ---,,,,,-.; Licensed Professional Engineer State of Texas No. 98398 Gessner Engineering 8 APPENDIX A: General location Map Gessner Engineering 9 Gessner Engineering 10 APPENDIX B: FEMA 100 Year Floodplain Map 95000 FT ibutary 10. 30° 33' 45" .t: dlf 0 BRAZOS COUNTY UNINCORPORATED AREAS 481195 00 0 MAP SCALE 1" = 1000' 1000 PANEL 0310E FLOOD INSURANCE RATE MAP BRAZOS COUNTY, TEXAS AND INCORPORATED AREAS PANEL 310 OF 475 (SEE MAP INDEX FOR FIRM PANEL LAYOUD ~ COMMUNITY BRAZOS COUNTY CCU.EGE STATION, CITY OF 48111:>5 <80063 0'.!10 0310 Notice to User: The Map Number shown below should be used when placing map orders; the Community Number shown above should be used on Insurance applications for the subject community. MAP NUMBER 48041C0310E MAP REVISED MAY 16, 2012 Federal Eme~ency Munagement Agency This Is an o!!iclal copy of a portion of the abow referenced flood map. It was extracted using F-MIT On-Line. This map does not reflect changes or amendments which may haw been made sub6equent to the date on the title block. For the latest product information about National Flood Insurance Program flood maps check the FEMA Flood Map Store at www.msc.fema.gov 11 APPENDIXC: Drainage Area Maps and Calculations 12 APPENDIX D: Hydrographs G 13 Subbasin 'PRE -AREA 1" Results for Run "PRE - 2 YEAR" o .oo r---Tl---:-,--~l-- 0.01 I i ! 0.02 1-I '2 0.03 l = ~ 0.04 w 0 0.05 0.06 ------t 0.07 o.oa...L----------------------'--------'------'--------''------~ 5-r-------,---------,------------.,..-------,-----,-----1 - , I I 4 ·i 2 oL-~~-.-~~--+~===:::::;::::::::::_~--.-~~-l-~-====t=====::;:=====~ 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :OD 00:0( I I Legend {Compub!! Ti~: 07Apr2014, 15:22:31) -Run: PRE - 2 YEAR Element: PRE -AREA 1 Result:Precipftation -Run: PRE -2 YEAR Element: PRE -AREA 1 Result:Precipftation Loss --Run:PRE - 2 YEAR Element:PRE -AREA 1 Result:Outflow - - -Run: PRE - 2 YEAR Element: PRE -AREA 1 Result:Baseflow Gessner Engineering G • 0.02 0.04 ~ 0.06 Q) 0 0.08 _,_ __ 0.10 Subbasin "PRE -AREA 1' Results for Run "PRE -10 YEAR" l ----! ---L I ___ J_ __ I r- 0.1 2-'------'-------'------------'-----------------------" ::~----------------+----------~j,..--------,.--------------, 8 -- 4 2 I f ol--~~~~~~====:::::::::::::::::::::;:::__~~~~~--l-~--====~=======;::========;I 00:00 03:00 06:00 09:00 I Legend (Compute Time: 07Apr2014, 15: 2.2:30) -Run:PRE -10 YEAR Bement:PRE -AREA 1 Result:Precipltation --Run: PRE -10 YEAR Bement: PRE -AREA 1 Result: Outflow 12:00 01Jan201 3 15:00 18:00 21:00 -Run: PRE -10 YEAR Element: PRE -AREA 1 Result: Precipitation Loss - --Run: PRE -10 YEAR Element: PRE -AREA 1 Resl.dt:Baseflow OO:OC I 14 Gessner Engineering G 15 Subbasin "PRE -AREA 1' Results for Run "PRE -25 YEAR" 0.00 0.02 ---1· 0.04 :§: 0.06 .<:: "E. Q) 0.08 0 0.10 0.12 _L. ·-----·- 14 12 10 8 ~ ~ :;: 6 0 i:L 4 ---- 2 --- 0 00:00 03:00 06:00 09:00 I Legend (Compute Time: 07Apr2014, 15:22:31) -Run:PRE -25 YEAR Element: PRE -AREA 1 Result:Precip~lllion --Run:PRE -25 YEAR Element:PRE -AREA 1 Result:Outflow I -1 12:00 f ! -----t--- J --~=-~---~-~ =-~--- I j. L ----4 ~----- __ J __ ~-- ----1------1---·------'I 1 15:00 18:00 21 :OD 00:0( 01Jan2013 I -Run:PRE -25 YEAR Element:PRE -AREA 1 Result:Precipillllion Loss - --Run:PRE -25 YEAR Element:PRE -AREA 1 Result:Baseflow Gessner Engineering G Subbasin "PRE -AREA 1" Results for Run "PRE -50 YEAR" 0.00 1 --1 1-------!lll, -- 0.02 I 0.04 '2 0.06 +- j l = '§. 0.08 a> 0 0.10-<---- 0.12 ~ 0.14-<---i -1- 0.16-'---------------------------------~----~----~ 15....----------------------------..,------..,.--------,---------,, 14 12 10 --+- 8 6 f- 4 2 I t i --r -f- 01-~~-.-~===;::=====:::::::::==~~~~~~-=====:======::;:=====d 16 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :00 00:0( I I Legend {Compute T1me: 07Ap.-2014, 15:22:31) -Run: PRE -50 YEAR Element: PRE -AREA 1 Result:Precipttation -Run: PRE -50 YEAR Elemert:PRE -AREA 1 Reslit:Precipttation Loss --Run:PRE -50 YEAR Element: PRE -AREA 1 Result:Outflow - - -Run: PRE -50 YEAR Elemert:PRE -AREA 1 Reslit:Baseflow Gessner Engineering G 17 Subbasin "PRE -AREA 1" Results for Run "PRE - 1 DD YEAR" 0.00 0.02 t- 0.04 0.06 c: "" 0.08 £;. ~ 0.10 0 0.12 0.14 0.16 -------- 0.18 18 16 14 12 i 10 :S "' 8 0 ;:;:: 6 4 2 0 00:00 03:00 06:00 09:00 I Legend (Compute Time: 07Apr2014, 15:22:30} -Rlll:PRE -100 YEAR Element: PRE -AREA 1 Result: Precipitation --Rt.r1:PRE -100 YEAR Element: PRE -AREA 1 Result: Outflow -l· - 12:00 01Jan2013 T I l 1 -+- 15:00 --+----- 18:00 21 :OO -Rt.n:PRE -100 YEAR Element:PRE -AREA 1 Result:Precipttation loss - --Rt.n:PRE -100 YEAR Element: PRE -AREA 1 Result:Baseflow 00:0( I Gessner Engineering G 18 Junction "SOUTWEST OUTLET" Results for Run "POST -2 YEAR" 5 i :§' 3-<-----···--~ 2 ---------1-----~ - - 06:00 09:00 --Run:POST -2 YEAR Bement:SOUTWEST OUTLET Result:Outflow ----- -Run:POST -2 YEAR Bement:POST -AREA 3 Result: Outflow ----Run:POST - 2 YEAR Bement:POST -AREA 4 Result: Outflow 12:00 01Jan2013 15:00 1 B:OO _[_] I 21 :OO OO:OC I ---Run: POST - 2 YEAR Element:REACH-2 Result:Outflow ---· Run: POST -2 YEAR Element:REACH-1 Result: Outflow Gessner Engineering G Junction "SOUTWEST OUTLET" Results for Run "POST -10 YEAR" 12~---------,-------1 -------,------,--/ ----,-------,, 10 ___ _J I : B -----l----~ --- I g 6-i------..,..-------. ----_! ________ - I I ;-----~- ~ LL. 4 2 I I o L-~~-----~~;;;:;;;;;;~~~~~~~~~;;;;~~;;;;:;;~~~~ 19 00:00 03:00 06:00 12:00 01Jan2013 15:00 1 B:OO 21 :OD DO:OC I I Legend (Compute1ime: 14Apr201'1, 14:36:26) --Run:POST -10 YEAR Element:SOUlV\JEST OUTLET Result:Outflow ---Run: POST -10 YEAR Elemenl:REACH-2 Resul:Outflow ----- -Run: POST -1 0 YEAR Element: POST -AREA 3 Result: Outflow ---· Run: POST -1 0 YEAR Elemenl:REACH-1 Resul: Outflow ----Run: POST -10 YEAR Element: POST -AREA 4 Result: Outflow Gessner Engineering G 20 Junction "SOUTWEST OUTLET" Results for Run "POST -25 YEAR" 14~-----------------------------,-------------------.,, _,l g ~ 12 10 8 - - -.... ;;: 6 ---~ +--[ [ I 4 -1---+-----~ - --- i-+- I 2 --,_ 00:00 03:00 06:00 09:00 I Legend (Compute Time: 14Apr2014, 14:36:28) --Run:POST -25 YEAR Element:SOUTl/\IEST OUTLET Result:Outllow ------Run: POST -25 YEAR Element: POST -AREA 3 Result:Outllow --- -Run: POST -25 YEAR Element: POST -AREA 4 Result:Outllow 12:00 01Jan2013 -- f 15:00 I 18:00 21 :00 - - -Run: POST -25 YEAR Element:REACH-2 Result:Outllow Run:POST -25 YEAR Element:REACH-1 Result:Outllow 00:0( I Gessner Engineering G 21 Junction "SOUTWEST OUTLET" Results for Run 'POST -50 YEAR" 12 10 -,~ 8 ---- ~ ~ ~ 0 Li: 6 -+ l-I 4 ·-----+------J------+ --,--__ j_ 00:00 03:00 06:00 09:00 I Legend (Compute 1ime: 14Apr2014, 14:36:31) --RL11:POST -50 YEAR Element:SOUlWEST OUTLET Resutt:Outflow ------Rl.11:POST -50 YEAR Element: POST -AREA 3 Result: Outflow ----Rl.11:POST -50 YEAR Element: POST -AREA 4 Resutt:Outflow ----. - --+------i ------<-------11 12:00 01Jan2013 15:00 -1-- 18:00 21 :00 ---Rl.11:POST -50 YEAR Element:REACH-2 Resutt:Outflow ---· RL11:POST -50 YEAR Element:REACH-1 Resutt:Outflow 00:0( I Gessner Engineering G 22 Junction "SOUTWEST OUTLET" Results for Run "POST -100 YEAR" 14 ------+ --r 12 L 10 t----- 6 4 2 06:00 09:00 --Run: POST -100 YEAR Element:SOUlVVEST OUTLET Resul:Outflow ------Run: POST -100 YEAR Element: POST -AREA 3 Result: Outflow -- --Run: POST -100 YEAR Element: POST -AREA 4 Result: Outflow 12:00 01Jan2013 . ----+. --- ---i------ 15:00 18:00 t-·-· -- --r---- J 21 :00 ---Run: POST -100 YEAR Element:REACH-2 Result: Outflow ---· Run:POST-100 YEAR Element:REACH-1 Result:Olillow 00:0( I Gessner Engineering 23 APPENDIX E: HEC-HMS Calculations G ~PRE-AREA 1 Pre-Developed HEC-HMS Model Project: 11-0355 Simulation Run: PRE -2 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Time: 18Mar2014, 11:31:25 Basin Model: 11-03SS PRE Meteorologic Model: 2 YR Control Specifications: Control 1 Show Sements: [All Elements .. j Volume Units: @ IN (j ACfl Sorting: I Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2} (CFS) (IN) PRE-AREA 1 0.0037 5.6 01Jan2013, 12:16 3.19 Project: 11-03.SS Simulation Run: PRE -10 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Time: 18Mar2014, 11:32:38 Basin Model: 11-0355 PRE Meteorologic Model: 10 YR Control Specifications: Control 1 Show Elements: [All Elements ... ] Volume Units: @ IN 0 ACfl Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) (CFS} (IN) PRE -AREA 1 0.0037 10.4 01Jan2013, 12: 16 6.07 Project: 11-0355 Simulation Run: PRE-25YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:.00 Compute Time: 18Mar2014 11:32:58 Basin Model: 11-0355 PRE Meteorologic Model: 25 YR Control Specifications: Control 1 Show Elements: [All Sements ,.. j Volume Units: @ IN () ACfl Sorting: [Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI4) (CFS) (IN) PRE-AREA 1 0.0037 12.5 01Jan2013, 12:16 7.34 24 Gessner Engineering G • Project:. ll-0355 Simulation Run: PRE -50 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Time : 18Mar2014, 11:34:27 Basin Model:: 11-0355 PRE Meteorologic Model: 50 YR Control Specifications: Control 1 Show Elements: !All Elements ,. j Volume Units: @ IN C) AC~ Sorting: [Hydrologic ,. j Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) (CFS) (IN) PRE-AREA 1 0.0037 14.1 01Jan2013, 12:16 8.32 Project: 11-0355 Simulation Run: PRE -100 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Time: 18Mar2014, 11:34:45 Basin Model: 11-0355 PRE Meteorologic Model: 100 YR Control Specifications: Control 1 Show Elements: I All Elements .,. j Volume Units: G IN 0 AC~ Sorting: f Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI~) (CFS) (IN) PRE -AREA 1 0.0037 16.3 01Jan2013, 12: 16 9.70 25 Gessner Engineering 26 POST -AREA2 ~POST -AREA 1 ~POST -AREA 6 °'I POST -AREA 5 G POST -AREA 3 Post-Developed HEC-HMS Model Gessner Engineering G Project: H-0355 Simulation Run: POST -2 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute Time: 14Apr2014, 14:36:29 Basin Model: 11-0355POST Meteorologic Model: 2 YR Control Specifications: Control 1 Show Elements: I All Elements .... 1 Volume Units: @ IN '.)AC-FT Sorting: [ Hydrologic .... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) (CFS) (IN) POST-AREA 5 0.0010470 2.2 01Jan2013, 12:08 3.52 POND2 0.0010470 1.0 01Jan2013, 12:24 3.52 Reach-2 0.0010470 1.0 01Jan2013, 12:24 3.52 POST-AREA 3 0.0013750 2.4 01Jan2013, 12: 13 3.51 POST-AREA.6 .000953 2.1 01Jan2013, 12:09 3.91 POND 1 .000953 1.7 01Jan2013, 12: 14 3.91 Reach-1 .000953 1.7 01Jan2013, 12: 15 3.91 POST -AREA. 4 .000328 0.6 01Jan2013, 12:08 2.95 SOLJTWEST OUTLET 0.0037030 5.5 01Jan2013, 12:14 3.57 POST-AREA.2 .00001733 0.0 01Jan2013, 12:07 4.26 POST-AREA 1 .00001679 0.0 01Jan2013, 12:07 4 .. 26 NORTH OUTLET .00003412 0.1 01Jan2013, 12:.07 4.26 Project:. 11-0355 Simulation Run: POST -10 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute Time: 14Apr2014, 14:36:26 Basin Model: 11-0355 POST Meteorologic Model: W YR Control Specifications: Control 1 Show Elements: I All 8ements .... ] Volume Units: O IN C) AC-FT Sorting: [.Hydrologic .... J Hydrologic Element POST-AREA 5 POND2 Reach-2 POST-AREA3 POST-AREA.6 POND 1 Reach-1 POST-AREA 4 SOU"nNEST OUTLET POST-AREA 2 POST-AREA 1 NORTH OUTLET Drainage Area (MI2) 0.0010470 0.0010470 0.0010470 0.0013750 .000953 .000953 .000953 .000328 0.0037030 .00001733 .00001679 .00003412 Peak Discharge Time of Peak Volume (CFS) (IN) 3.9 01Jan2013, 12:08 6."16 1.9 01Jan20131 12:22 6. "16 1.9 01Jan2013, 12:22 6. "16 4.3 01Jan2013, 12:13 6.44 3.5 01Jan2013, 12:09 6.88 3.2 01Jan2013, 12:13 6.88 3.2 01Jan2013, 12:14 6.88 1.2 01Jan2013, 12:07 5.78 10.2 01Jan2013, 12: 13 6.50 0.1 01Jan2013, 12:07 7.25 0.1 01Jan2013, 12:07 7.25 0.1 01Jan2013, 12:07 7.25 27 Gessner Engineering G Project: 11-0355 Simulation Run: POST -25 YEAR Start of Run: 01Jan2013 00:00 End of Run: 02Jan20:l3, 00:02 Compute Time: 14Apr2014, 14:36:28 Basin Model: 11-0355 POST Meteorologic Model: 25 YR Control Specifications.: Control 1 Show Bements: [All Bements .... j Volume Units: t!} IN 0 ACB Sorting: [ Hydrologic ... j Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) {CFS) (IN) POST-AREA 5 0.0010470 4.6 01Jan2013, 12:08 7.74 POND2 0.0010470 2.3 01Jan2013, 12:21 7.74 Reach-2 0.0010470 2.3 01Jan2013, 12:21 7.74 POST -AREA 3 0.0013750 5.1 01Jan2013, 12: 13 7.72 POST -AREA 6 .000953 4.2 01Jan2013, 12:09 8.18 POND 1 .000953 3.8 01Jan2013, 1.2: 12 8.18 Reach-1 .000953 3.8 01Jan2013, 12: 13 8.17 POST -AREA4 .000328 1.4 01Jan2013, 12:07 7.04 SOLJTWEST OUTLET 0.0037030 1.2.1 01Jan2013, 12:13 7.78 POST-AREA 2 .00001733 0.1 O 1Jan2013, 12: 07 8.55 POST-AREA 1 .00001679 0.1 01Jan2013, 12:07 8.55 NORTH OUTLET .00003412 0.2 01Jan2013, 12:07 8.55 Project: 11-0355 Simulation Run: POST -SO YEAR Start of Run: 01Jan201.3, 00:00 End of Run: 02Jan2013, 00:02 Compute Time: 14Apr2014, 14:36:31 Basin Model: 11-0355 POST Meteorologic Model: SO YR Control Specifications: Control 1 Show Elements: I All Be:ments .... J Volume Units: @ IN () AC-FT Sorting: [ Hydrologic ... J Hydro logic Element POST-AREA 5 POND2 Reach-2 POST-AREA 3 POST -AREA 6 POND 1 Reach-1 POST -AREA 4 SOLJTWEST OUTLET POST -AREA 2 POST -AREA 1 NORTH OUTLET Drainage Area (MI2) 0.0010470 0.0010470 0.0010470 0.00:13750 .000953 .000953 .000953 .000328 0.0037030 .00001733 .00001679 .00003412 Peak Discharge (CFS) 5.2 2.6 2.6 5.8 4.6 4.3 4.3 1.6 13.7 0.1 0.1 0.2 Time of Peak 01Jan2013, 12:08 01Jan2013, 12:21 01Jan2013, 12:21 01Jan2013, 12: 13 01Jan2013, 12:09 01Jan2013, 12:12 01Jan2013, 12:13 01Jan2013, 12:07 01Jan2013, 12:13 01Jan2013, 12:07 01Jan2013, 12:07 01Jan2013, 12:07 Volume (IN) 8.73 8.73 8.73 8.71 9.17 9.17 9.17 8.01 8.77 9.5.S 9.5.S 9.55 28 Gessner Engineering G Project: 11-0355 Simulation Run: POST-100 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 02Jan2013, 00:02 Compute Time: 14Apr2014, 14:36:25 Basin Model: 11-0355 POST Meteorologic Model: 100 YR Control Specifications: Control 1 29 Show Elements: [All Elements ... j Volume Units: (!)IN Q ACB Sorting: [ Hydrologic ... J Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) {CFS) (IN) POST -AREA 5 0.0010470 6.0 01Jan2013, 12:08 10.12 POND2 0.0010470 3.0 01Jan2013, 12:21 10.12 Reach-2 0.0010470 3.0 01Jan2013, 12:21 10.12 POST -AREA 3 0.0013750 6.6 01Jan2013, 12:13 10.10 POST -AREA 6 .000953 5.3 01Jan2013, 12:09 10.57 POND 1 .000953 4.9 01Jan2013, 12:12 10.57 Reach-1 .000953 4.9 01Jan2013, 12:13 10.56 POST-AREA4 .000328 1.8 01Jan2013, 12:07 9.38 SOUTWEST OlJTlET 0.0037030 15.7 01Jan2013, 12:13 10.16 POST -AREA 2 .00001733 0.1 01Jan2013, 12:07 10.95 POST -AREA 1 .00001679 0.1 01Jan2013, 12:07 10.95 NORTH OlJTlET .00003412 0.2 01Jan20131 12:07 10.95 Gessner Engineering 30 APPENDIX F: Technical Design Summary G--------------------------~~n~~~neeri~ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) Engineering and Design Professionals Information Engineering Firm Name and Address: Jurisdiction Gessner Engineering City: Bryan 2501 Ashford Drive Suite 102 x College Station College Station, TX 77840 Date of Submittal: Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: Jeremy N. Peters, 979-680-8840, jpeters@gessnerengineering.com Supporting Engineering I Consulting Firm(s): Other contacts: Developer I Owner I Applicant Information Developer I Applicant Name and Address: Phone and e-mail: Chuck Moreau -Moreau Family Investments, Ltd. 764-4084 1834 Harris Drive chuck@bvcarpetoutlet.com College Station, TX 77845 Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: Project Identification Development Name: Brazos Valley Floor and Design Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? Site Project If multi-phase, subject property is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) Lot 10, Block 1, Rock Prairie West Business Park If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. General Location of Project Area, or subject property (phase): Rock Prairie & Wellborn In City Limits? Extraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: 2.38 acres. Acreage Outside ET J: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: N. Graham Rd., Old Wellborn Rd. Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: Final Plat File #: Date: Name: Status and Vol/Pg: If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: PPD fX~:iiR~ or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Preliminary Report Required? No Submittal Date Review Date Review Comments Addressed? Yes --No --In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of storrnwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coo rd i nation Dept. Contact: Date: Subject: With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? Yes No X ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): TAMUS Needed? Yes No x ---- Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective in spaces below. Entity Permitted or Status of Actions (include dates) Approved? US Army Crops of Engineers No x Yes --- US Environmental Protection Agency No x Yes --- Texas Commission on Environmental Quality No x Yes ---- Brazos River Authority No x Yes --- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Progert~ Characteristics I Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Site _X_ Redevelopment of one platted lot, or two or more adjoining platted lots. Development __ Building on a single platted lot of undeveloped land. Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ Construction of streets and utilities to serve one or more platted lots. Development __ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of Construction of new parking lot for existing building and construction of new Pro Rosed 12,000 SF warehouse Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No Yes ---- FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I No _X __ Yes __ (Section II, Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain I No _X_ Yes Rate Map area of a FEMA-regulated watercourse? -- Encroachment(s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No x -- Yes -- If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Progert)l Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (&date) here, and attach copy if not already in City files. -- Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi-phase project, describe stormwater management x plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? _X __ No --Yes Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? _X_ No --Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) _X __ Detention is required. --Need must be evaluated. __ Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -ProQert~ Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? x No Yes If yes, --describe splits below. In Part 4 describe desiqn concept for handlinq this. Watershed or Basin Larger acreage Lesser acreage Above-Project Areas(Section II , Paragraph 83-a) Does Project Area (project or phase) receive runoff from upland areas? _X_ No --Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? --No --Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? x No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Property Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage If yes, for what part of length? % Created by? __ plat, or easements __ instrument. If instrument(s), describe their provisions. exist for any part of pathway(s)? X No Pathway Areas Nearby Yes Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Detention pond on adjacent property. Drainage 1--~~~~~~~~~~~~~-,-~~~~~~~~~~~~~~~~_, Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? _x_ No __ Yes If yes, explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section , or discharge point. Discharge(s) To Lower Property(ies) (Section II , Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No Yes Separate Instrument? x No Yes ---- Per Guidelines reference above, how will __ Establishing Easements (Scenario 1) runoff be discharged to neighboring _x_ Pre-development Release (Scenario 2) property(ies )? Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# ) Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) detention Com bi nation: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? No --Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters / Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or >---~~~~~~~~~~~~~~~~~~~~~~~~~~~ between Watersheds? What design and mitigation is used to compensate for increased runoff from gaining basin or watershed? X No Yes How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 1. __ With facility(ies) involving other development projects. 2. _x __ Establishing features to serve overall Project Area. 3. __ On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit# ) Two detention ponds; one located to the southwest of the proposed building and one to the northwest of the building. 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. C-· -0 Q) (/) Are aquatic echosystems proposed? _x__ No __ Yes In which phase(s) or project(s)? c Q) ~ >-Are other Best Management Practices for reducing stormwater pollutants proposed? 0::: _x_ No __ Yes Summarize type of BMP and extent of use: (/) c .Ql (/) Q) 0 Oz co ! xi Q) ~ If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. __ Detention elements __ Conduit elements __ Channel features __ Swales __ Ditches __ Inlets __ Valley gutters __ Outfalls __ Culvert features __ Bridges Other STORMWATER DESIGN GUIDELINES . Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No _X __ Yes Identify type and general size and In which phase(s). Culvert under drives at NW and SW of the Proposed Building. If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): Property is served by two detention ponds; one to the NW and one to the SW of the proposed building. Both ponds discharge to SW of site. Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? __ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. C'-· l:J Cll en en :::i Cll en >- CD I ~ .B '6 Typical shape? I Surfaces? Steepest side slopes: Usual front slopes: Usual back slopes: Flow line slopes: least. ____ _ Typical distance from travelway: typical ___ _ greatest. ___ _ (Attached Exhibit# ) Are longitudinal culvert ends in compliance with B-CS Standard Specifications? ___ Yes No, then explain: At intersections or otherwise, do valley gutters cross arterial or collector streets? ___ No __ Yes If yes explain: Are valley gutters proposed to cross any street away from an intersection? __ No __ Yes Explain: (number of locations?) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? --Yes --No If "no", identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? --Yes --No If no, explain where and why not. C'-· "O Q) en Will inlet size and placement prevent exceeding allowable water spread for 10-year ::l .._ 2 design storm throughout site (or phase)? --Yes --No If no, explain. "5 Ol -o~ c "O C1J Q) Sag cuNes: Are inlets placed at low points? Yes No Are inlets and ..0 ~ -- --.._ ·-conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? ::l ...... u c Yes No Explain "no" answers. ..c 8 -- --~-3: en ...... Q) Q) .._ Ui Q) Will 100-yr stormflow be contained in combination of ROW and buried conduit on .._ <!: whole length of all streets? Yes No If no, describe where and why. ---- Do designs for curb, gutter, and inlets comply with 8-CS Technical Specifications? Yes --No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? __ No --Yes Identify length(s) and where used. C'-· "O Pipe runs between system I Typical a> en Longest en a> access points (feet): ::l >- Ii Are junction boxes used at each bend? --Yes --No If not, explain where and why. en c ·-0 ~z i xl Are downstream soffits at or below upstream soffits? Least amount that hydraulic en grade line is below gutter line .!!J. Yes No __ If not, explain where and why: --(system-wide): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) -Describe watercourse(s), or system(s) receiving system discharge(s) below en (include design discharge velocity, and angle between converging flow lines). Cl) (.) c 1) Watercourse (or system), velocity, and angle? co Ui c ·- Cl) L.. -o ~ E 2) Watercourse (or system), velocity, and angle? :J L.. c 0 ·-..,_ c . o~ (.) c -·--E w ~ w E co 3) Watercourse (or system), velocity, and angle? ..... co ~en ..,_ en aJ :J c :Q 0 ·-> ~ e -0 Q_ E ..... For each outfall above, what measures are taken to prevent erosion or scour of L.. Cl) 0 Cl) receiving and all facilities at juncture? ..... ..c CfJ en Cl) 1) -ro L.. co 2) Q_ Cl) en c 3) ~ Are swale(s) situated along property lines between properties? --No --Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): C'-· en Qi ~ en ..... Q) Flow line slopes (minimum and maximum): en >-c ! I ~ 0 en Z :J Outfall characteristics for each (velocity, convergent angle, & end treatment). i xl en Q) L.. Will 100-year design storm runoff be contained within easement(s) or platted drainage <( ROW in all instances? --Yes --No If "no" explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) en Q) .c g 0 Q) :Q en -0 co 0 0:: en Q) >- lw c 0 co z Ui 1 ~ 0 C'-· :E -0 en -0 Qi co c >. c co c .c co (.) .... c .E Q) c 0.. 0 0 ~ -0 E :::J .... .!!! 0 -c c Q) -0 E Q) co en en :::J en Q) c -0 0 ·;;: ~ 0 .... c 0.. :0 (ii E Q) 0 .c (.) en ...... Q) :::J ro -0 .... c co 0 0.. (.) Q) --en Q) rn c 3: ~ en Q) .... <( Are roadside ditches used? _X_ No __ Yes If so, provide the following: Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes __ No Are top of banks separated from road shoulders 2 feet or more? __ Yes Are all ditch sections trapezoidal and at least 1.5 feet deep? __ Yes No No For any "no" answers provide location(s) and explain: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: Is 100-year design flow contained in conduit/swale combination? If "no" explain: Space for 100-year storm flow? ROW Easement Yes Width Swale Surface type, minimum and maximum slopes: Conduit Type and size, minimum and maximum slopes, design storm: Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Access Describe how maintenance access is provided (to swale, into conduit): Instance 2 Describe general location, approximate length: Is 100-year design flow contained in conduit/swale combination? If "no" explain: Space for 100-year storm flow? ROW Easement Yes Width Swale Surface type, minimum and maximum slopes: Conduit Type and size, minimum and maximum slopes, design storm : Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Access Describe how maintenance access is provided (to swale, into conduit): No No STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 .. SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters J Continued (Page 4.7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: c ·ro E a. x 0 w L... ..... ~ ui Is 100-year design flow contained in swale? --Yes --No Is swale wholly 0 Cl) within drainage ROW? Yes No Explain "no" answers: c >-I :::l ---- L... Cl) > ·a; Access Describe how maintenance access is provide: (.) Cl) L... 0 ...... z :::l l:l 1 c 0 (.) Instance 2 Describe general location, approximate length, surfacing: l:l Cl) ·;:: C'· :::l en .0 ...... c :J Cl) 0 E £ Cl) en Is 100-year design flow contained in swale? Yes No Is swale wholly ·~ Cll ----Cl) within drainage ROW? __ Yes No Explain "no" answers: en L... Cl) 0 --co 5: ~ en 0 ~ 0::: Access Describe how maintenance access is provided: .~ :0 :::l Q_ Instance 3, 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? No Yes If only slightly ----shaped, see "Swales" in this Part. If creating side banks, provide information below. C'· l:l .s Will design replicate natural channel? Yes No If "no", for each instance Cl) -----en ~ describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year 0 Q_ Q_ x design flow, and amount of freeboard: 0 w L... Q_ Instance 1: en en c Cl) Cl) >- E I Cl) > Instance 2: 0 L... Q_ E 0 ·-z Q) xi c Instance 3: c Cll ..c u STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters J Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? x No Yes ----If "ves" provide the information below. Will small creeks and their floodplains remain undisturbed? _x_ Yes No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. ~ "O Q) :::i c ~ Watercourses (and tributaries): Aside from fringe changes, are Regulatory 0 Watercourses proposed to be altered? _x_ No __ Yes Explain below. ~ (/) c Submit full report describing proposed changes to Regulatory Watercourses. Address Q) existing and proposed section size and shape, surfaces, alignment, flow line changes, E Q) length affected, and capacity, and provide full documentation of analysis procedures > 0 and data. Is full report submitted? Yes No If "no" explain: L.. o_ -- E - Q) c c co All Proposed Channel Work: For all proposed channel work, provide information ..c u requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? --Yes --No If not, identify location and explain: . Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4-Drainage Conce~t and Design Parameters I Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? 2 For each provide info. below. For each dry-type facilitiy: Facility 1 POND 1 Facility 2POND 2 Acres served & design volume+ 10% 0.61 ac 0.061 ac-ft 0.67 ac 0.165 ac-ft 100-yr volume: free flow & plugged 0.028ac-ft 0.055 ac-ft 0.61 0.15 ac-ft Design discharge (10 yr & 25 yr) 3.2 cfs 3.8 cfs 1.9 cfs 2.3 cfs Spillway crest at 100-yr WSE? _x_yes --no _x _yes --no Berms 6 inches above plugged WSE? _x_yes --no _x __ yes --no Explain any "no" answers: C/l (!) >- 1 For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: 3.8 cfs 0 z Facility 2: 2.3 cfs I Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: _x_ Yes No Facility 2: x Yes No -- ----C-· If "no" explain: -a (!) C/l 0 ()_ 0 L.. a.. For each, what is velocity of 25-yr design discharge at outlet? & at spillway? C/l 4.75 ft/sec 13.22 ft/sec & 4.38 ft/sec (!) Facility 1: & Facility 2: :e ·c::; Are energy dissipation measures used? No __x_ Yes Describe type and ro -- LL location: c Riprap at discharge points 0 ~ (!) -(!) 0 (!) For each, is spillway surface treatment other than concrete? Yes or no, and describe: L.. <( Facility 1: no, concrete weir Facility 2: no, concrete weir For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Riprap Facility 2: Riprap If berms are used give heights, slopes and surface treatments of sides. Facility 1: Pond 1: no berms, grass side slopes 10%-25% Pond 2: berm on plan north and west sides, 1.2' max. berm height, Facility 2: grass side slopes 16%-23% STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with 8-CS Specifications? Yes or no, and explain if "no": (fJ Facility 1; yes (!) :;:; :: -"(3 "O ct! (!) Facility 2: yes LL ::::i c c:.;::; 0 c :;:; 0 c (.) ai--For additional facilities provide all same information on a separate sheet. (!) 0 Are parking areas to be used for detention? _X_ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? No x Yes If "yes", provide information in next two boxes. ---- Will 25-yr. flow pass without flowing over driveway in all cases? x Yes No ---- Without causing flowing or standing water on public roadway? x Yes No ---- Designs & materials comply with 8-CS Technical Specifications? _X_ Yes --No Explain any "no" answers: C'-· (fJ Ol c (fJ Are culverts parallel to public roadway alignment? _X_ Yes No Explain: (fJ 0 --'-(fJ (.) (!) 2 >--~ I a_x Creeks at Private Drives: Do private driveways, drives, or streets cross drainage -ways that serve Above-Project areas or are in public easements/ ROW? ct! "O 0 x No Yes If "yes" provide information below. (!) z -- --(fJ I ::::i How many instances? Describe location and provide information below. (fJ t (!) Location 1: ..2: ::::i (.) (!) Location 2: '-<( Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 - SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulato!'.Y Watercourses (&Tributaries): Are culverts proposed on these facilities? x No __ Yes, then provide full report documenting assumptions, --criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: -Arterial or Major Collector Streets: Will culverts serve these types of roadways? Qi Q) x No Yes How many instances? For each identify the ..r:::. Cll -- Q) location and provide the information below. Cll ro Instance 1: Q) .... >-~ I ~ Instance 2: Instance 3: c 0 o~ Yes or No for the 100-year design flow: 1 2 3 ZE xii Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E C'-· co Is velocity limited per conditions (Table C-11 )? Cll Cll g1-o Explain any "no" answer(s): ·-c ~co 0 c .... 0 (.) ·->-ro co (.) 3: ..Q "O Q) co ..Cl Minor Collector or Local Streets: Will culverts serve these types of streets? 0 ·-........ (.) (.) x No Yes How many instances? for each identify the ·-Cll -Q) ----.g "O location and provide the information below: a. Q) ..... a. Instance 1: co~ "O >. Instance 2: Q) c Cll co :::i '+-Instance 3: Cll 0 t:: Cll Q) Q) For each instance enter value, or "yes" I "no" for: 1 ~ (.) 2 3 :::i c (.) co Design yr. headwater WSE 1 ft. below curb top? Q) Ui .... c <( ·-100-yr. max. depth at street crown 2 feet or less? Q) .... 0 Product of velocity (fps) & depth at crown (ft) =? E .... g Is velocity limited per conditions (Table C-11 )? Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? Yes ----No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? __ No __ Yes If yes, identify location(s) and provide justification : -Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? "O No Yes If "yes" identify location(s), describe outfall design treatment(s): Cll ----:::J c :.-:::; c 0 ~ (/) t Cll Is scour/erosion protection provided to ensure long term stability of culvert structural ~ :::J components, and surfacing at culvert ends? __ Yes __ No If "no" Identify () locations and provide justification(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? __ Yes --No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? _x_ No --Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? -(/) Q) Ol -0 ·;::: en A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: £ Pollution Prevention construction entrance, erosion control silt fence, hay bales at (ij Plan (SW3P) pond discharge points ::I a established for L.. project construction? Q) -co x ~ No Yes -- -- Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? x No Yes If "yes" list general type and location below. ---- Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? STORMWATER DESIGN GUIDELINES Effective February 2007 Yes ---- Page 22 of 26 No If "no" explain: APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concegt and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements --Channel features -- Culvert features Swales Ditches Inlets Outfalls ---------- __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology Is a map(s) showing all Design Drainage Areas provided? _x __ Yes --No Briefly summarize the range of applications made of the Rational Formula: N/A. Rational Method can not be used for detention design per BCS Std. Design Guidelines. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? acres Location (or identifier): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? 100 No x Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? __ X_ No __ Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall 2, 10, 25, 50, & 100 100 Detention facilities: outlet and conveyance structure(s) 2, 10, 25, 50, & 100 2, 10,25,50,& 100 Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: For conduit type(s) Coefficients: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.1 6) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? No Yes Head and friction losses No Yes -- ------ Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? --Yes --No Are elevation drops provided at inlets, manholes, and junction boxes? --Yes --No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? --Yes --No For 100-year flow conditions? --Yes --No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? __ Yes __ No If "no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Effective February 2007 Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher Part 5 -Plans and S~ecifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical DesiQn Summary DrainaQe Report by siQninQ and sealino below. ''This report (plan) for the drainage design of the development named in Part B was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued or fall under applicable general per:~':"'''' --of TE~ \ (Affix se£'\'············~8 '' ~~ 'A..':···~ ...••• "'_,.. • •• • I , • • •.• 'I . ........, I! • • ••• • ; ·········· ~"s 1. l.. . ······ 1'~0 .•. "I. Licensed Professional Engineer State of Texas PE No. 98398 STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of 26 l . ... p •••• l .,,_...... ·ss" . ······· : l t-AE\.~········3 9 8 I fl J ,,. ... ~·· . 98 ~ :g; ii .. ~ ··if~ ··-~·· LICE"~ • ..:;.f1 -' ... ... ·-:. .... • - '\\ ?"ESSIOM~---~ APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 FOR OFFICE USE ONLY CASE NO.: l t_\ -T) $ CITY OP COllEGE STATION Home o/Teras A&M Univmity0 DATE SUBMITTED: \ \ ( tZ..I (<-\ TIME: lO=o o SITE PLAN APPLICATION GENERAL STAFF: {)\~ -'-'-------- MINIMUM SUBMITTAL REQUIREMENTS: fRl $932 Site Plan Application Fee. fRl fRl $350 Non-Residential Architectural Standards I Northgate Building Review Application Fee (if applicable). $600 (minimum) Development Permit Application I Public Infrastructure Review and Inspection Fee. Fee is 1 % of ~cceptabl.e Engineer's Estimate for public infrastructure, $600 minimum (if fee is > $600, the balance is due prior to the issuance of any plans or development permit). fRl Application completed in full. This application form provided by the City of College Station must be used and may not be adjusted or altered. fRl Six (6) folded copies of site plan. fRl One (1) folded copy of the landscape plan. fRl One (1) copy of the following for Non-Residential Architectural Standards building review or Northgate Building Review (if applicable). 18] [g] fRl Building elevations to scale for all buildings. fRl A list of building materials for all facade and screening. fRl Color samples for all buildings or lis t colors to be used from the approved color palette. [BJ lectronic copy of Site Plan e-mailed to csuelectdesign@cstx.gov. Two (2) copies of the grading, drainage, and erosion control plans with supporting drainage report. Two (2) copies of the Public infrastructure plans and supporting documents (if applicable). 0 Traffic Impact Analysis or calculations of projected vehicle trips showing that a TIA is not necessary for the proposed request (if applicable). lg] The attached Site Plan Non-Residential Architectural Standards Building Review and Northgate Building Review checklists (as applicable) with all items checked off or a brief explanation as to why they are not check off. Date of Optional Preapplication or Stormwater Management Conference ----------------- NAME OF PROJECT Brazos Valley Floor and Design ADDRESS 12900 Old Wellborn Road LEGAL DESCRIPTION (Lot, Block, Subdivision) Lot 10, Block 1, Rock Prairie West Business Park APPLICANT/PROJECT MANAGER'S INFORMATION (Primary contact for the project): . . Jeremy Peters -Gessner Engineering E-mail jpeters@gessnerengmeenng.com Name Street Address 2501 Ashford Drive, Suite 102 C II St t. State TX Zip Code 77840 City o ege a ion ------- Phone Number .:....(9_7..:.9)~6_8_0_-8_8_4_0 __________ Fax Number (979) 680-8841 PROPERTY OWNER'S INFORMATION: N Moreau Family Investments -Chuck Moreau E-mail chuck@bvcarpetoutlet.com ame .:.::..::..:...:...:::.:.....:_:___::_ ____________ _ Street Address 1834 Harris Drive St t TX Zip Code 77845 City College Station a e ________ _ _____ _ Phone Number .:_(9_7_9:....~ _2_1 a_-_B_B3_5 ___________ Fax Number Revised 4/14 Page 1 of 11 FOR OFFICE USE ONLY 'CASE NO.: l t..\ -7) s DATE SUBMITTED: \ \ ! 1'2.--) (L\. TIME: \O:oo CrTY or Coll.EGE STATION Home a/Texas A&M Univmity" SITE PLAN APPLICATION GENERAL STAFF: A~ ------~~~~~~~~ MINIMUM SUBMITTAL REQUIREMENTS: ~ $932 Site Plan Application Fee. ~ $350 Non-Residential Architectural Standards I Northgate Building Review Application Fee (if applicable). [8] $600 (minimum) Development Permit Application I Public Infrastructure Review and Inspection Fee. Fee is 1 % of acceptable Engineer's Estimate for public infrastructure, $600 minimum (if fee is > $600, the balance is due prior to the issuance of any plans or development permit). lg] Application completed in full. This application form provided by the City of College Station must be used and may not be adjusted or altered. ~ Six (6) folded copies of site plan. lg] One (1) folded copy of the landscape plan . lg] One (1) copy of the following for Non-Residential Architectural Standards building review or Northgate Building Review (if applicable). lg] Building elevations to scale for all buildings. lg] A list of building materials for all facade and screening. lg] Color samples for all buildings or list colors to be used from the approved color palette. lg] Electronic copy of Site Plan e-mailed to csuelectdesign@cstx.gov. lg] Two (2) copies of the grading, drainage, and erosion control plans with supporting drainage report. lg] Two (2) copies of the Public infrastructure plans and supporting documents (if applicable). 0 Traffic Impact Analysis or calculations of projected vehicle trips showing that a TIA is not necessary for the proposed request (if applicable). lg] The attached Site Plan Non-Residential Architectural Stanf:iards Building Review and Northgate Building Review checklists (as applicable) with all items checked off or a brief explanation as to why they are not check off. Date of Optional Preapplication or Stormwater Management Conference ~~~~~~~~~~~~~~~~- NAME OF PROJECT Brazos Valley Floor and Design ADDRESS 12900 Old Wellborn Road LEGAL DESCRIPTION (Lot, Block, Subdivision) Lot 10, Block 1, Rock Prairie West Business Park APPLICANT/PROJECT MANAGER'S INFORMATION (Primary contact for the project): Name Jeremy Peters -Gessner Engineering E-mail jpeters@gessnerengineering.com Street Address 2501 Ashford Drive, Suite 102 City College Station State TX Zip Code _7_78_4_0 ____ _ Phone Number (979) 680-8840 Fax Number (979) 680-8841 ~~~~~~~~~~~~~~~- PROPERTY OWNER'S INFORMATION: Name Moreau Family Investments -Chuck Moreau E-mail chuck@bvcarpetoutlet.com Street Address 1834 Harris Drive City College Station State TX Zip Code 77845 ~~~~~~~~--~~~~~~- Phone Number (979) 218-8835 Fax Number ~~~~~~~~~~~~~~~~ Revised 4/14 Page 1 of 11 _,>... ~ARCHITECT OR ENGINEER'S INFORMATION: Name Jeremy Peters -Gessner Engineering E-mai 1 jpeters@gessnerengineering.com Street Address 2501 Ashford Drive, Suite 102 City College Station State TX Zip Code _7_78_4_0 ____ _ Phone Number (979) 680-8840 Fax Number (979) 680-8841 ----------------- 0 THE R CONTACTS (Please specify type of contact): Name Street Address City State ---------Zip Code Fax Number -----------------Phone Number Current zoning POD -------------------------------------- Present use of property Granite Sales ---------------------------------~ Proposed use of property Granite Sales ---------------------------------- Number of parking spaces required 44 Number of parking spaces proposed 44 -------- Is there Special Flood Hazard Area (Zone A or Zone AE on FEMA FIRM panels) on the property? I Yes IX No This information is necessary to help staff identify the appropriate standards to review the application and will be used to help determine if the application qualifies for vesting to a previous ordinance. Notwithstanding any assertion made, vesting is limited to that which is provided in Chapter 245 of the Texas Local Government Code or other applicable law. Is this application a continuation of a project that has received prior City platting approval(s) and you are requesting the application be reviewed under previous ordinance as applicable? I Yes r No If yes, provide information regarding the first approved application and any related subsequent applications (provide additional sheets if necessary): Project Name: City Project Number (in known): Date I Timeframe when submitted: Revised 4/14 Page 2 of 11 .._' MUL Tl-FAMILY RESIDENTIAL Total Acreage Floodplain Acreage ____ _ Housing Units # of 1 Bedroom Units --- ___ #of 2 Bedroom Units ___ # of 3 Bedroom Units #of 4 Bedroom Units --- FOR 2 BEDROOM UNITS ONLY #Bedrooms= 132 sq . ft. --- #Bedrooms< 132 sq . ft. --- PARKLAND DEDICATION (Fees due prior to the issuance of a Building Permit) #of Multi-Family Dwelling Units X$1636=$ # of acres in floodplain # of acres in detention #of acres in greenways Date dedication approved by Parks & ____ Recreation Advisory Board COMMERCIAL Total Acreage Building Square Feet ___ _ Floodplain Acreage ____ _ * Projects that were vested prior to January 1, 2008, per Chapter 245 of the Texas Local Government Code may be assessed a different amount. Please contact city staff for additional information. repared this application and certifies that the facts stated herein and exhibits attached hereto are true /I l1z-f1+- Date Revised 4/14 Page 3of11 CERTIFICATIONS REQUIRED FOR ALL DEVELOPMENT Owner Certification: 1. No work of any kind may start until a permit is issued. 2. The permit may be revoked if any false statements are made herein. 3. If revoked, all work must cease until permit is re-issued. 4. Development shall not be used or occupied until a Certificate of Occupancy is issued. 5. The permit will expire if no significant work is progressing within 24 months of issuance. 6. Other permits may be required to fulfill local, state, and federal requirements. Owner will obtain or show compliance with all necessary State and Federal Permits prior to construction including NOi and SWPPP. 7. If required, Elevation Certificates will be provided with elevations certified during construction (forms at slab pre- pour) and post construction. 8. Owner hereby gives consent to City representatives to make reasonable inspections required to verify compliance. 9. If, stormwater mitigation is required, including detention ponds proposed as part of this project, it shall be designed and constructed first in the construction sequence of the project. 10. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that all debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply. 11 . The information and conclusions contained in the attached plans and supporting documents will comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines Technical Specifications, and Standard Details. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 12. Release of plans to (name or firm) is authorized for bidding purposes only. I understand that final approval and release of plans and development for construction is contingent on contractor signature on approved Development Permit. 13. I, THE OWNE GREE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR THE D P NT PERMIT APPLICATION, ARE, TO THE BEST OF MY KNOWLEDGE, TRUE, AND X ACC lfjZ-1/4- Property Owner(s) Date Engineer Certification: 1. The project has been designed to ensure that stormwater mitigation, including detention ponds, proposed as part of the project will be constructed first in the construction sequence. 2. I will obtain or can show compliance with all necessary Local, State and Federal Permits prior to construction including NOi and SWPPP. Design will not preclude compliance with TPDES: i.e., projects over 10 acres may require a sedimentation basin. 3. The information and conclusions contained in the attached plans and supporting documents comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 4. I, THE ENGINEER, AGREE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR THE DEVELOR ENT PERMIT APPLICATION , ARE, TO THE BEST OF MY KNOWLEDGE, TRUE, AND ACCURATE. /1//1 //'1 Date Revised 4/14 Page 4 of 11 CITY or Coll.EGE STATION Home o/Ttxas A&M University" SITE PLAN MINIMUM REQUIREMENTS (ALL CITY ORDINANCES MUST BE MET) INCLUDING BUT NOT LIMITED TO THE FOLLOWING: lg] Sheet size -24" x 36" (minimum). lg] A key map (not necessarily to scale). lg] Title block to include: [g] Name, address, location, and legal description [g] Name, address, and telephone number of applicant [g] Name, address, and telephone number of developer/owner (if differs from applicant) [g] Name, address, and telephone number of architect/engineer (if differs from applicant) [g] Date of submittal [g] Total site area lg] North arrow. lg] Scale should be largest standard engineering scale possible on sheet. lg] Ownership and current zoning of parcel and all abutting parcels. lg] The total number of multi-family buildings and units to be constructed on the proposed project site. lg] The density of dwelling units per acre of the proposed project. lg] The gross square footage of all buildings and structures and the proposed use of each. If different uses are to be located in a single building, show the location and size of the uses within the building. Building separation is a minimum of 15 feet w/o additional fire protection. Locations of the following on or adjacent to the subject site: Designate between existing and proposed lg] The density of dwelling units per acre of the proposed project. lg] Phasing. Each phase must be able to stand alone to meet ordinance requirements. lg] Buildings (Existing and Proposed). ~ Setbacks according to UDO, Article 5. Geography lg] Water courses. lg] 100 yr. floodplain and floodway (if applicable) on or adjacent to the proposed project site. Please note if there is none on the site with confirming FEMA/FIRM map number. lg] Existing topography (2' max or spot elevations) and other pertinent drainage information. (If plan has too much information, show drainage on separate sheet.) lg] Proposed grading (1 ' max for proposed or spot elevations) and other pertinent drainage information. (If plan has too much information, show drainage on separate sheet.) Revised 4/14 Page 7 of 11 Streets, Parking, and Sidewalks l8] Existing streets and sidewalks (R.O.W.). fg] Existing Driveways, both opposite and adjacent to the site according to UDO, Article 7. fg] Proposed drives. Minimum drive aisle width according to UDO, Article 7 18] Indicate proposed driveway throat length according to UDO, Article 7 ~ Proposed curb cuts. 18] For each proposed curb cut (including driveways, streets, alleys, etc.) locate existing curb cuts on the same and opposite side of the street to determine separation distances between existing and proposed curb cuts. 18] Proposed curb and pavement detail. 18] A 6" raised curb is required around all edges of all parts of all paved areas without exception. (To include island, planting areas, access ways, dumpster locations, utility pads, etc.) No exception will be made for areas designated as "reserved for future parking". [8J Proposed medians. 18] Proposed sidewalks (both public and private). 18] Proposed pedestrian/bike circulation and facilities for non-residential buildings (UDO, Article 7). 18] Off-Street parking areas with parking spaces drawn, tabulated, and dimensioned. [8J Designate number of parking spaces required by ordinance and provided by proposal. 18] Handicap parking spaces. 18] Parking Islands drawn and dimensioned with square footage calculated according to UDO, Section 7.2 or 7.9 fornon- residential buildings. 18] Parking setback from R.O.W. to curb of parking lot as required. 18] Wheelstops may be required when cars overhang onto property not awned by the applicant or where there may be conflict with pedestrian or bike facilities, handicap accessible routes or above ground utilities, signs or other conflicts. [8J Security gates, showing swing path and design specs with colors. 18] Guardrails. Include design and colors. [8J Traffic Impact Analysis for non-residential development (UDO, Article 7). [8J Please note if none is required. 18] Will there be access from a TxDOT R.O.W.? D Yes 18] No If yes, then TxDOT permit must be submitted with this application. Easements and Utilities [8J Easements -clearly designate as existing or proposed and type (utility, access, etc.) [8J Utilities (noting size and designate as existing or proposed) within or adjacent to the proposed site, including building transformer locations, above ground and underground service connections to buildings, and drainage inlets. 18] Sewer Design Report (if applicable). [8J Water Design Report and/or Fire Flow Report (if applicable). 18] Drainage Report with a Technical Design Summary. 18] Meter locations, existing and proposed (must be located in public R.O.W. or public utility easement). [8J Provide a water and sanitary sewer legend to include [8J Minimum water demands [8J Maximum water demands 18] Average water demands in gallons per minute, and 18] Maximum sewer loadings in gallons per day 18] Will there be access from a TxDOT R.O.W.? D Yes 18] No If yes, then TxDOT permit must be submitted with this application. Revised 4/14 Page 8 of 11 · · Fire Protection ~ Show fire lanes. Fire lanes with a minimum of 20 feet in width with a minimum height clearance of 14 feet must be established if any portion of the proposed structure is more than 150 feet from the curb line or pavement edge of a public street or highway. ~ Show proposed and existing fire hydrants. Fire hydrants must be located on the same side of a major street as a project, and shall be in a location approved by the City Engineer. Any structure in any zoning district other than R-1, R-1A, or R-2 must be within 300 feet of a fire hydrant as measured along a public street, highway or designated fire lane. NOTE: Fire hydrants must be operable and accepted by the City, and drives must have an all weather surface before a building permit can be issued. ~ Will building be sprinkled? ~ Yes O No If the decision to sprinkle is made after the site plan has been approved, then the plan must be resubmitted . If Yes , ~ Show fire department connections. FDC's should be within 100' of the fire hydrant. They shall be accessible from the parking lot without being blocked by parked cars or a structure. Landscaping ~ Landscape plans as required in Article 7 of the Unified Development Ordinance. The landscaping plan can be shown on a separate sheet if too much information is on the original site plan. If requesting protected tree points, then those trees need to be shown appropriately barricaded on the landscape plan. Attempt to reduce or eliminate plantings in easements. Include information on the plans such as: [8J required point calculations [8J additional streetscape points required . Streetscape compliance is required on all streets. [8J calculations for # of street trees required and proposed (proposed street tree points will accrue toward total landscaping points.) [8J proposed new plantings with points earned [8J proposed locations of new plantings [8J screening of parking lots, 50% of all shrubs used for screening shall be evergreen. 1v1 screening of dumpsters, concrete retaining walls, off street loading areas, utility connection points, or other ~ areas potentially visually offensive. [8J existing landscaping to remain 1v1 show existing trees to be barricaded and barricade plan. Protected points will only be awarded if barricades are ~ up before the first development permit is issued. [8J Buffer as required in Article 7 of the Unified Development Ordinance. [8J Show irrigation system plan. (or provide note on how irrigation system requirement will be met prior to issuance of C. 0.) All plans must include irrigation systems for landscaping. Irrigation meters are separate from the regular water systems for buildings and will be sized by city according to irrigation demand submitted by applicant and must include backflow prevention protection. ~ Is there any landscaping in TxDOT R.O.W.? O Yes ~ No If yes, then TxDOT permit must be submitted at the time of application. Other ~ Common open spaces sites ~ Loading docks [gJ Detention ponds [gJ Retaining walls ~ Sites for solid waste containers with screening. Locations of dumpsters are accessible but not visible from streets or residential areas. Gates are discouraged and visual screening is required . (Minimum 12 x 12 pad required.) ~ Are there impact fees associated with this development? D Yes (8J No NOTE: Signs are to be permitted separately. Revised 4/14 Page 9of11 ···c.r-- C ITY or C oLLEGE STATION Home o/Texas A&M University' NRA BUILDING REVIEW MINIMUM REQUIREMENTS (ALL CITY ORDINANCES MUST BE MET) INCLUDING BUT NOT LIMITED TO THE FOLLOWING: Refer to UDO Section 7 .9 Non-Residential Architectural Standards, as appropriate. ~ Sheet size -24" x 36" (minimum). ~ Title block to include: ~ Name, address, location, and legal description ~ Name, address, and telephone number of applicant ~ Name, address, and telephone number of developer/owner (if differs from applicant) ~ Name, address, and telephone number of architect/engineer (if differs from applicant) ~ Date of submittal ~ Scale should be largest standard scale possible on sheet. lg] List of colors from the City of College Station color palette to be utilized or proposed equivalents. ~ Color samples. ~ List of materials to be utilized. ~ Elevations of each non-residential building and screening structure. Show placement of materials and colors on the facades according to UDO Section 5.6.B or 7.9. ~ Include the following dimensions: ~ Total vertical square footage minus openings (for each fagade separately) ~ Total vertical square footage of transparency (for each fagade separately in Northgate) lg] Total vertical square footage of each building material (for each fagade separately) ~ Total vertical square footage of each color (for each fagade separately) ~ Graphic representation and/or description of existing buildings in building plot to show material, color, and architectural harmony. Revised 4/14 Page 10 of 11 Engineer's Estimate of Infrastructure Construction Costs Brazos Valley Floor and Design November 12, 2014 Gessner Engineering, LLC GE Job #: 11-0355 WATER SYSTEM Item# Item Quanitiy I Units I Unit Cost Total 100 Demo, Remove, Replace Asphalt Pavement 120 I SF I$ 20.00 $ 2,400.00 Sub Total -Water System $2,400.00 Construction Cost $2,400.00 10% Contingency $240.00 Total Construction Cost $2,640.00 Engineer's Estimate of Infrastructure Construction Costs Brazos Valley Floor and Design November 12, 2014 Gessner Engineering, LLC GE Job #: 11-0355 WATER SYSTEM Item# Item Quanitiy I Units I Unit Cost Total 100 Demo, Remove, Replace Asphalt Pavement 120 I SF I$ 20.00 $ 2,400.00 Sub Total -Water System $2,400.00 Construction Cost $2,400.00 10% Contingency $240.00 Total Construction Cost $2,640.00 May 29, 2014 Mr. Alan Gibbs, P.E. City Engineer City of College Station 1101 Texas Avenue College Station, TX 77840 Re : Wastewater Design Report Brazos Valley Floor and Design 12900 Old Wellborn Road College Station, Texas Gessner Engineering Job No.: 11-0355 Dear Mr. Gibbs: The existing Brazos Valley Floor and Design building is served by an On-Site Sewage Facility (OSSF). The subject tract will also be serviced by an OSSF to be designed by others to support the adjacent existing facility as well. Please contact us if you have any questions or if we can be of further assistance. Sincerely, GESSNER ENGINEERING, LLC F-7451 Melissa P. Thomas, P.E. C)?~G Joshua B. Van Wie, E.l.T., M.S. G Gessner Engineering 250 I Ashford Drive Suite I 02 College Scarion, Texas 77840 P.O. Box 10763, 77842-0763 979.680.8840 FAX 979.680.8841 2204 S. Chappell Hill Sr. Brenham, Texas 77833 979.836.6855 FAX 979.836.6847 May 29, 2014 Mr. Alan Gibbs, P.E. City Engineer City of College Station 1101 Texas Avenue College Station, TX 77840 Re : Domestic Water Report Brazos Va lley Floor and Design 12900 Old Wellborn Road College Station, Texas Gessner Engineering Job No.: 11-0355 Dear Mr. Gibbs: The subject tract is served water by Wellborn Special Utility District and will not require service from College Station Util ities. Please contact us if you have any questions or if we can be of further assistance. Sincerely, GESSNER ENGINEERING, LLC F-7451 Melissa P. Thomas, P.E. C)?~G Joshua B. Van Wie, E.l.T., M.S. G Gessner Engineering 250 I Ashford Drive Suite 102 College Station, Texas 77840 P.O. Box 10763, 77842-0763 979.680.8840 FAX 979.680.884 L 2204 S. Chappell Hill St. Brenham, Texas 77833 979.836.6855 FAX 979.836.6847 .. COMMENT RESPONSES STAFF REVIEW COMMENTS NO. 1 Project: 12900 Old Wellborn Rd (SP) 14-00900275 PLANNING · 1) The parking calculation for the office use should be 1 /350 as defined by the ordinance guiding the POD . Please revise the calculations to reflect this requirement and adjust parking as needed . Site plan revised as noted. • 2) Please revise the building setback lines to show as follows: a) Side Street Setback ( N. Graham Rd.) 15 feet b) Rear Setback 20 feet Setbacks on Site Plan. (and other plans they are visible on) revised as noted · 3) Warehouse dimensions seem to be wrong when scaled out. Please revise the dimension labels, or change the total area label to reflect accurate dimensions. FYI... the parking calculation for the warehouse should also be updated with the revised total square footage. Also, the open covered storage area that is tied to the warehouse does not get factored into the parking calculation . Please revise the square footage calculation in the table to reflect this change as well. Site plan dimensions and sf calculation revised as noted as well as parking calculation. Parking lot revised removing parking spaces along Old Wellborn Road that were no longer required with the revised parking tabulation. · 4) Please show the location of the bicycle racks on the. Bicycle rack added and called out adjacent to parking facing Old Wellborn Road. · 5) Please provide the volume and page of the public utility easement existing on the property. Volume and Page or pue added to the site plan as noted. · 6) Please clearly identify paving areas, particularly within the proposed outdoor display area. It is hard to define where the pavement is ending on the plan. Hatch added on site plan to clarify the paving areas/ extents of outdoor display area. ' 7) On the side of the existing 2,255 sq. ft. building there is a 5 feet side walk and 18.5 feet long parking spaces. The minimum sidewalk width should be 6 feet in order to have 18.5 feet parking spaces. Please change the width of the sidewalk to be 6 feet in width. Please also note that this change will affect the parking spaces and drive aisle width. Sidewalk modified to 6' in width on all sheets as noted. · 8) The curb return radii measured at the entrance of N. Graham Rd. is labeled as 15 feet. The minimum radii for commercial driveways is 25 feet. Please revise to meet this requirement. Radii revised as noted on site plan and all sheets. • 9) Please label the existing sign on the property. Please also provide a general note stating that all proposed signage shall be permitted separately as required by the College Station Unified Development Ordinance. Existing sign labeled on the site plan along Old Wellborn Road and note added regarding proposed signage as note 7 on the site plan as noted. 10) Provide a general note on the site plan that states the following: Exterior building and site lighting will meet the standards of Section 7.11 of the Unified Development Ordinance. The light source shall not project below an opaque housing and no fixture shall directly project light horizontally. Fixtures will be mounted in such a manner that the projected cone of light does not cross any property line. Added as note 5 on the site plan 11) Please correct the street label to say N. Graham Road. Street label revised on site plan and all other sheets as noted. Please note that any changes made to the plans that have not been requested by the City of College Station must be explained in your next transmittal letter. Any additional changes on these plans that the City has not be made of aware of will constitute a completely new review. Noted Reviewed by: Mark Bombek Date: 12-02-2014 LANDSCAPING/STREETSCAPING/BUFFER 1) Please clearly identify the property line. Also note that it appears some of the plantings may ie:.~~ be located within the Right-of-way (ROW). Vegetation within the ROW does not count ~ towards the required points for the project. If you are proposing landscape improvements in the ROW you will need to file a PIP application with our department to approve that proposal. Property is now clearly seen and all plantings have been shifted to be included within the property. 2) Please remove existing buildings and paving details from the plan. All existing structures to be demolished have been removed from the plan. 3) Please provide a more clear plant schedule. Plant schedule has been clarified as noted. . 4) The landscape point calculations seem to be off. Please make the following revisions. a. For the Streetscape calculation, please separate the frontage calculation for North Graham Rd . and Wellborn. They should have their own subtotal and not lumped together as one frontage calculation. Frontage calculations for streetscape have been added on the far right of the sheet. b. The canopy tree calculation under streetscape points should be divided by 32 feet not 30 feet. Calculations revised as noted c. At the end of the calculation table please remove the note saying 'actual points (excluding streetscape & screening)'. This is not needed as streetscape points and site landscape points are totaled together to determine the required points for the entire site. Revised as noted 5) There shou ld also be a separate calculation identifying that 50% of the total required points are allotted to canopy trees. Separate calculation for canopy trees added as noted. . 6) Please provide a general note on the Landscape plan stating that 100% coverage of groundcover, decorative paving, decorative rock, or perennial grass is required in parking lot islands, swales, and drainage area, the parking lot setback, rights-of way, and adjacent property disturbed during construction. Note added below the calculations ' 7) Please correct the street label to show N. Graham Rd . Street Label revised as noted. Reviewed by: Mark Bombek Date: 12-02-2014 MISCELLANEOUS 1) Please provide the general note on the landscape plan that the Irrigation system must be protected by a Pressure Vacuum Breaker, a Reduced Pressure Principle Back Flow Device, or a Double-Check Back Flow Device, and installed as per City Ordinance 2394. .. - Note added below calculations 2) All Back Flow devices must be installed and tested upon installation as per City Ordinance 2394. Wording added to note above to clarify this requirement. ENGINEERING COMMENTS NO. 1 1. Check your Building Data Summary on coversheet, it doesn't correspond with the site plan and is not complete. Also provide the building type building type, utility demand. Building Data summary table updated on the site plan. 2. Please use revised Firm map dated 4/2/2014 when determining if the site is located in floodplain/floodway. Revised as noted on the site plan. 3. Please fix the scale bars on the sheets, some sheets have 2 scale bars .overlapping making it not possible to read what the scale is. Scale Bars revised as noted on applicable sheets 4. The minimum curb return radii for commercial driveway is 25 feet. Curb return radii revised as noted. 5. Please add a note stating that the site is in Steeplechase-Wellborn impact fee area. FYI the fee is $144.87 per LUE (Living Unit Equivalent) which is due during the building permit and is based on meter size. Note 33 added to the utility plan. 6. Please show existing location of septic tank and associated system on site plan . Site plan will not be approved without documentation from health department approving the system . Septic design is being re-designed (currently) with a drip irrigation disposal system. The area of the system and the disposal area are hatched on the site plan. We have worked with the septic designer to layout where this location will be in accordance with the health department rules and regulations 7. Provide a FDC for the proposed warehouse. FYI the FDC needs to be within 100 feet of a fire hydrant along the fire lane. FOG provided as noted. 8. Pullback the ripraps to the property line or include grouting or some other method to ensure that rip rap does not become an issue when maintaining the bar ditch. Riprap pulled back to the property line as noted. 9. Please provide erosion control in Graham Rd .'s ditch line Revised as noted. 1 a.According to GIS contours, it appears that the runoff on the adjacent property will flow through this property when driveway connections are made. This additional flow is not taken into account in the drainage report or the grading plan. Please address this issue. The driveways are graded to have a ridge to keep the adjacent flow from coming onto the property. Spot elevations have been provided along the ridge for clarity. 11 . Please provide a letter from Wellborn SUD that they are willing and have capacity to serve this development. I have been in contact with Stephen Cast with Wellborn SUD and he is in the process of getting us the capacity letter. 12. Provide detention storage calculations for plugged conditions and associated emergency overflows. Provided on page 18 of the Technical Design Summary and in the drainage report 13. Please make sure that the berm is at least 6 inches above the clogged 100- year water surface elevation, and that the top width correspondence with our guidelines. Information provided in the drainage report showing that these requirements are met. 14. Please provide the depth & velocity calculations for the swale adjacent to Detention pond 2. Also include a profile view for the proposed swale. How are you planning to red irect the runoff 90 degrees? FYI a berm may be required between the swale & the adjacent lot depending on the information provided. This swale has been deleted, pond 1 now flows into pond 2. 15. On the grading plan, provide adjacent grades of abutting properties. Grades at all tie in locations at existing are showing as well as the existing contours extend onto abutting properties. 16. Provide the culvert design criteria , and calculations that were used to determine the size of the culvert. Please complete the culvert section in Appendix D in the Technical Design summary. Also verify that the upstream headwater elevation is at least 1 foot below the lowest top of curb of the crossing. Culvert design criteria has been included in the Drainage report as appendix F and the culvert section has been filled out in the Technical Design Summary. 17. Please confirm that the elevation of the discharge allows daylighting and that it will not cause ponding in the ROW. A note should be added that the contractor ensures positive downstream grading due to the shallow grades along Graham Rd. Grading of discharge has been modified slightly to ensure daylighting and note added as note #14 as requested to sheet C4. 0. 18. Have there been correspondence with the engineer and architecture regarding the roof downspout's locations since placement could affect drainage basin areas. yes 19. FYI the following comments were provided by our Utilities Department. These may change after our scheduled meeting with Utility department, Planning & Development Services, and Fire Department scheduled for December 8, 2014. Noted Utilities' Comments 1) Label backflow prevent as "RPZ Assembly" Cl. 0 Revised as noted 2) Place RPZ closer to the tie-in location so that it will not allow any dead water back into our system. RPZ shifted as close to the tie in location as possible. There is not room to put it on the other side of the road right at the tie in. 3) Include a 24" gate valve on the northern leg of the proposed tie-in tee. C7. 0 Revised as noted 4) Provide a plan and profile of the proposed waterline. Profile added on C7. 0. 5) Prove steel encasement for waterline crossing of roadway. Steel encasement added to the profile as noted. 6) Please include executed agreement with College Station Utilities for maintenance of proposed lines/appurtenances as part of re-submittal package. I spoke with Stephen Maldonado on May 4 and he said that this was no longer required. 7) Include note that tie-in to take place on only Tuesday and Thursday between the hours of 9am -3pm and will require a 1 week advance notice. Note 14 added on C7.0. 8) Label waterline material as 6" PVC C-900 DR14 Waterline. Revised as noted on Cl. O 9) Verify that hydrant/main located in existing ROW/ proposed easements. There is a 20 ' PUE along Old Wellborn Road and a 1 O' PUE along the northwest property line in which the main and fire hydrant are situated. 1 O)FYI monthly flushing fees may be required and paid to utility department. Noted Reviewed by: Kevin Ferrer FIRE 1) Building will require Fire Sprinkler and Fire Alarm. Noted Date: December 2, 2014 2) Building will require a Fire Lane. If the building requires a Fire Lane longer than 100' a turn a- round will be needed. Response 3) If the eve of the building is over 29' an Aerial Access Easement will be required. If an AAE is required a turn-a-round will be needed because the entire side of the building will be covered by the AAE. The highest point on the building is 23'-3", so no AAE required. 4) A Knox Box will be needed. Get with the Fire Marshal's Office for an application. Noted Reviewed by: Steve Smith Date: 11/17/14 ELECTRICAL COMMENTS REQUIRING IMMEDIATE ATTENTION 1. This project location is outside of CSU certification area . CSU will not provide electric service to this project location. Noted GENERAL ELECTRICAL COMMENTS 1. To discuss any of the above electrical comments please contact Gilbert Martinez at 979.764.6255. Noted Reviewed by: Gilbert Martinez Date: 12/01/2014 SANITATION 1. Need to contact Sanitation on trash dumpster for new building. Noted Reviewed by: Wally Urrutia Date: November 18, 2014 _____ -4-1-.;_IL._.lfi=-OO=-OU> W£LL.t)C> ILN -------------------------1 8ET R MEMORANDUM DATE: December 3, 2014 TO: Jeremy Peters, via; jpeters@gessnerengineering.com FROM: Mark Bombek, Staff Planner SUBJECT: 12900 OLD WELLBORN RD (SP) Staff reviewed the above-mentioned site plan as requested. The following page is a list of staff review comments detailing items that need to be addressed. Please address the comments and submit the following information for further staff review: City of College Station Transmittal Letter; Memo providing written responses to all of staff's comments (identify the specific page that each comment was addressed on or the reason for not addressing the comment); One (1) complete sets of site civil construction documents for the proposed development with the revised site and landscaping plans attached (one set will be returned to you , please submit additional copies if you want more than one approved set); One (1) 24"x36" revised site plans; One (1) 24"x36" landscaping plan; Please note that this application will expire in 90 days from the date of this memo, if the applicant has not provided written response comments and revised documents to the Administrator that seek to address the staff review comments contained herein. If there are comments that you are not addressing with the revised site plan, please attach a letter explaining the details. If you have any questions or need additional information, please contact Mark Bombek at 979.764.3570. Attachments: Staff Review Comments PC: Moreau Family Investments, via; chuck@bvcarpetoutlet.com P&DS Project No. 14-00900275 Planning & Development Services P.O. BOX 9960 • 1101 TEXAS AVENUE · COLLEGE STATION · TEXAS · 77842 TEL 979.764.3570 ·FAX. 979.764.3496 cst><.gov/devservices STAFF REVIEW COMMENTS NO. 1 Project: 12900 Old Wellborn Rd (SP) 14-00900275 PLANNING ./ 1) The parking calculation for the office use should be 1 /350 as defined by the ordinance guiding the POD. Please revise the calculations to reflect this requirement and adjust parking as needed . ./ 2) Please revise the building setback lines to show as follows: a) Side Street Setback ( N. Graham Rd .) 15 feet b) Rear Setback 20 feet ~ Warehouse dimensions seem to be wrong when scaled out. Please revise the dimension labels, or change the total area label to reflect accurate dimensions. FYI... the parking calculation for the warehouse should also be updated with the revised total square footage. Also, the open covered storage area that is tied to the warehouse does not get factored into the parking calculation. Please revise the square footage calculation in the table to reflect this change as well. /4) Please show the location of the bicycle racks on the. /' 5) Please provide the volume and page of the public utility easement existing on the property. v 6) Please clearly identify paving areas, particularly within the proposed outdoor display area. It is hard to define where the pavement is ending on the plan. ~) On the side of the existing 2,255 sq. ft. building there is a 5 feet side walk and 18.5 feet long parking spaces. The minimum sidewalk width should be 6 feet in order to have 18.5 feet parking spaces. Please change the width of the sidewalk to be 6 feet in width. Please also note that this change will affect the parking spaces and drive aisle width. ~ The curb return radii measured at the entrance of N. Graham Rd . is labeled as 15 feet. The minimum radii for commercial driveways is 25 feet. Please revise to meet this requirement. ~) Please label the existing sign on the property. Please also provide a general note stating that all proposed signage shall be permitted separately as required by the College Station Unified Development Ordinance. 0) Provide a general note on the site plan that states the following: Exterior building and site lighting will meet the standards of Section 7.11 of the Unified Development Ordinance. The light source shall not project below an opaque housing and no fixture shall directly project light horizontally. Fixtures will be mounted in such a manner that the projected cone of light does not cross any property line. vf 1) Please correct the street label to say N. Graham Road. /f 2) Please note that any changes made to the plans that have not been requested by the City of College Station must be explained in your next transmittal letter. Any additional changes on these plans that the City has not be made of aware of will constitute a completely new review. Reviewed by: Mark Bombek Date: 12-02-2014 rl LANDSCAPING/STREETSCAPING/BUFFER ~1) Please clearly identify the property line. Also note that it appears some of the plantings may be located within the Right-of-way (ROW). Vegetation within the ROW does not count towards the required points for the project. If you are proposing landscape improvements in the ROW you will need to file a PIP application with our department to approve that proposal. 2) Please remove existing buildings and paving details from the plan. 3) Please provide a more clear plant schedule. 4) The landscape point calculations seem to be off. Please make the following revisions. v"'a) For the Streetscape calculation, please separate the frontage calculation for North Graham Rd . and Wellborn. They should have their own subtotal and not lumped / together as one frontage calculation. b) The canopy tree calculation under streetscape points should be divided by 32 feet not 30 feet. /c) At the end of the calculation table please remove the note saying 'actual points (excluding streetscape & screening)'. This is not needed as streetscape points and site landscape points are totaled together to determine the required points for the entire site . ./ d) There should also be a separate calculation identifying that 50% of the total required points are allotted to canopy trees. 5) Please provide a general note on the Landscape plan stating that 100% coverage of groundcover, decorative paving, decorative rock, or perennial grass is required in parking lot islands, swales, and drainage area, the parking lot setback, rights-of way, and adjacent property disturbed during construction . 6) Please correct the street label to show N. Graham Rd . Reviewed by: Mark Bombek Date: 12-02-2014 MISCELLANEOUS 1. Please provide the general note on the landscape plan that the Irrigation system must be protected by a Pressure Vacuum Breaker, a Reduced Pressure Principle Back Flow Device, or a Double-Check Back Flow Device, and installed as per City Ordinance 2394. 2. All Back Flow devices must be installed and tested upon installation as per City Ordinance 2394. ENGINEERING COMMENTS NO. 1 1. Check your Building Data Summary on coversheet, it doesn't correspond with the site plan and is not complete. Also provide the building type building type, utility demand. 2. Please use revised Firm map dated 4/2/2014 when determining if the site is located in floodplain/floodway. 3. Please fix the scale bars on the sheets, some sheets have 2 scale bars overlapping making it not possible to read what the scale is . 4. The minimum curb return radii for commercial driveway is 25 feet. 5. Please add a note stating that the site is in Steeplechase-Wellborn impact fee area . FYI the fee is $144.87 per LUE (Living Unit Equivalent) which is due during the building permit and is based on meter size. 6. Please show existing location of septic tank and associated system on site plan . Site plan will not be approved without documentation from health department approving the system. 7. Provide a FDC for the proposed warehouse . FYI the FDC needs to be within 100 feet of a fire hydrant along the fire lane. 8. Pullback the ripraps to the property line or include grouting or some other method to ensure that rip rap does not become an issue when maintaining the bar ditch. 9. Please provide erosion control in Graham Rd.'s ditch line. 10 . According to GIS contours, it appears that the runoff on the adjacent property will flow through this property when driveway connections are made. This additional flow is not taken into account in the drainage report or the grading plan. Please address this issue. 11 . Please provide a letter from Wellborn SUD that they are willing and have capacity to serve this development. 12. Provide detention storage calculations for plugged conditions and associated emergency overflows. 13. Please make sure that the berm is at least 6 inches above the clogged 100-year water surface elevation, and that the top width correspondence with our guidelines. 14. Please provide the depth & velocity calculations for the swale adjacent to Detention pond 2. Also include a profile view for the proposed swale. How are you planning to redirect the runoff 90 degrees? FYI a berm may be required between the swale & the adjacent lot depending on the information provided. 15. On the grading plan, provide adjacent grades of abutting properties. 16. Provide the culvert design criteria, and calculations that were used to determine the size of the culvert. Please complete the culvert section in Append ix D in the Technical Design summary. Also verify that the upstream headwater elevation is at least 1 foot below the lowest top of curb of the crossing . 17. Please confirm that the elevation of the discharge allows daylighting and that it will not cause ponding in the ROW. A note should be added that the contractor ensures positive downstream grading due to the shallow grades along Graham Rd . 18. Have there been correspondence with the engineer and architecture regarding the roof downspout's locations since placement could affect drainage basin areas. 19 . FYI the following comments were provided by our Utilities Department. These may change after our scheduled meeting with Utility department, Planning & Development Services, and Fire Department scheduled for December 8, 2014. Utilities' Comments 20 . Label backflow prevent as "RPZ Assembly" 21 . Place RPZ closer to the tie-in location so that it will not allow any dead water back into our system. 22. Include a 24" gate valve on the northern leg of the proposed tie-in tee. 23. Provide a plan and profile of the proposed waterline. 24 . Prove steel encasement for waterline crossing of roadway. 25 . Please include executed agreement with College Station Utilities for maintenance of proposed lines/appurtenances as part of re-submittal package. 26. Include note that tie-in to take place on only Tuesday and Thursday between the hours of 9am -3pm and will require a 1 week advance notice. 27. Label waterline material as 6" PVC C-900 DR 14 Waterline. 28. Verify that hydrant/main located in existing ROW/ proposed easements. 29. FYI monthly flushing fees may be required and paid to utility department. Reviewed by: Kevin Ferrer Date: December 2, 2014 FIRE 1) Building will require Fire Sprinkler and Fire Alarm. 2) Building will require a Fire Lane. If the building requires a Fire Lane longer than 100' a turn- a-round will be needed. 3) If the eve of the building is over 29' an Aerial Access Easement will be required. If an AAE is required a turn-a-round will be needed because the entire side of the building will be covered by the AAE. 4) A Knox Box will be needed. Get with the Fire Marshal's Office for an application. Reviewed by: Steve Smith Date: 11/17/14 ELECTRICAL COMMENTS REQUIRING IMMEDIATE ATTENTION 1. This project location is outside of CSU certification area. CSU will not provide electric service to this project location. GENERAL ELECTRICAL COMMENTS 1. To discuss any of the above electrical comments please contact Gilbert Martinez at 979.764.6255. Reviewed by: Gilbert Martinez Date: 12/01/2014 SANITATION 1. Need to contact Sanitation on trash dumpster for new building. Reviewed by: Wally Urrutia Date: November 18, 2014 """ilillli:""'""'""'""'""'""...,...,~~~~~~~~C:ITY~OF COLLEGE STATIONI -~~,.._._. ............................. ,., Home a/Texas A&M University• ; MEMORANDUM DATE: November 14, 2014 Jeremy Peters, via; jpeters@gessnerengineering.com / TO : FROM: Mark Bombek, Staff Planner SUBJECT: 12900 OLD WELLBORN RD (SP) Thank you for the submittal of your Site Plan -Commercial application. Jason Schubert, Principal Planner, Kevin Ferrer, Graduate Engineer I, and I have been assigned to review this project. It is anticipated that the review will be completed and any staff comments returned to you on or before Tuesday, December 2, 2014. If you have questions in the meantime, please feel free to contact us. PC: Moreau Family Investments, via; chuck@bvcarpetoutlet.com P&DS Project No. 14-00900275 Planning & Development Services / P.O. BOX 9960 • l l Ol TEXAS AVENUE ·COLLEGE STATION ·TEXAS • 77842 TEL. 979.764.3570 ·FAX. 979.764.3496 cstx.gov/devservices PROJECT: )'Z.qoo OIAJ vJ~ lf.D DATE: 1z../6/1'"t DESCRIPTION: Mt Sd?~ 1U CnYoF COLLEGE STATION w s-rO""e/l J A: i,Jpc..~r0 cuJ WATER SERVICES DEPARTMENT -. -·1 I j I i I I 'n-, · l -·1-1 I I l 1 ! I I f I-i ,,-....--+ +--! --J--i-----l-~-u • ~-+ 1 ! f + : --1-t t I ' JI!('':~~= :[: l t1 · __,_ .~ : _ :_I 1.~1 --4--1--- 1 . I . I ! t-i I i : I . I ; ; l I 1!1, UJ_! il I ! ! --r'--;..~~--j_-r-ri ! I ---~ +-i . 1· : _, 1-.. -I I I ·-!_-t-~ . i _ _.. --~ I r· + -I -t 1 -, i_ t -t-! t-1 4 -t --i-I I I i I I i I i I t I -! I I THE CITY OF COLLEGE STATION,1601 Graham Road College Station, Texas 77842 P 979-764-3660 F 979-764-3452 WWW.CSTX.GOV May 7, 2015 Gessner Engineering Job No. 11-0355 Prepared for: Moreau Family Investments, Ltd. Mr. Chuck Moreau In Accordance with: Unified Stormwater Design Guidelines City of Bryan/City of College Station Prepared by: GESSNER ENGINEERING, LLC College Station, Texas DRAINAGE DESIGN REPORT Brazos Valley Floor and Design College Station, Texas G May 7, 2015 Mr. Alan Gibbs, P.E. City Engineer City of College Station 1101 Texas Avenue College Station, TX 77840 Re : Storm Water Drainage Study Brazos Valley Floor and Design 12900 Old Wellborn Road College Station, Texas Gessner Engineering Job No.: 11-0355 Dear Mr. Gibbs, 2 This report conveys the results of the storm water drainage study conducted by Gessner Engineering for the proposed redevelopment of Brazos Valley Floor and Design, College Station, Texas. Gessner Engineering believes that all information contained in this report is valid. Please contact us if you have any questions or if we can be of further assistance. This report for the drainage design for Brazos Valley Floor and Design was prepared by Gessner Engineering in accordance with provisions of the Bryan/College Station Unified Stormwater Design Guidelines for the owner of the property. Sincerely, GESSNER ENGINEERING LLC, F-7451 Melissa P. Thomas, P.E. 3 TABLE OF CONTENTS EXECUTIVE SUMMARY ........................................................................................................................... 4 INTRODUCTION ...................................................................................................................................... 4 CA LC ULA TIONS ....................................................................................................................................... 5 Time of Concentration ................................................................................................................. 5 Unit Hydrograph .......................................................................................................................... 6 Reach Routing .............................................................................................................................. 6 Peak Runoff Flow ......................................................................................................................... 6 Peak Post-Developed Runoff Flow ............................................................................................... 7 CONCLUSION .......................................................................................................................................... 7 APPENDIX Appendix A: General Location Map Appendix 8: FEMA 100 Year Floodplain Map Appendix C: Drainage Area Map and Calculations Appendix D: Hydrographs Appendix E: HEC-HMS Calculations Appendix F: Driveway Culvert Calculations Appendix G: Technical Design Summary Gessner Engineering G 4 EXECUTIVE SUMMARY This storm water drainage report is submitted to the City of College Station, Texas for review on April 2, 2014 by Melissa P. Thomas, P.E. of Gessner Engineering, located at 2501 Ashford Drive, Suite 102, College Station, Texas 77840. The proposed project consists of the demolition of the asphalt pavement serving the current building and construction of a 15,000 square foot {SF) warehouse and associated new concrete parking. The site will be served by two detention ponds in series. The total area of construction is approximately 2.38 acres. The subject site currently contains a 2,434 SF retail building to remain, a 1,963 sf metal canopy, a 1,112 sf metal awning, and a 24,631 SF of existing parking lot and hardscape all to be removed. The site is located directly northwest of the intersection of Old Wellborn Road and N. Graham Road . The site is located in the Hopes Creek watershed. The site is not located in the FEMA 100 year flood plain, as shown by FIRM number 48041C0310E. This firmette is included as Appendix B. Runoff from the overall drainage area generally flows south until reaching N. Graham Road. Water then flows southwest through a small drainage ditch along N. Graham Road until reaching a tributary of Hopes Creek. Runoff from the subject site reaches N. Graham Road by sheet flow and shallow concentrated flow through a small channel in the center of the property. Runoff from the Carpet Outlet site is stored in a detention pond in the southern corner of the property and discharged to flow across the property to the southwest of both lots until reaching N. Graham Road . Under existing conditions, the total flow exiting the lot and reaching the drainage ditch on N. Graham Road is 16.3 cubic feet per second {cfs) at the peak of the 100 year, Type Ill, 24 hour storm event. After development, runoff will be stored in a series of two detention ponds on the subject property and discharged at the southern corner of the property directly into the ditch along N. Graham Road. Under proposed conditions the flow into the drainage ditch is 15.7 cfs, at the same storm event. Additionally, a small portion of the two driveways along the north property line discharges 0.2 cfs onto the existing Brazos Valley Floor and Design site at the same storm event. The total peak flow of the subject tract under the proposed conditions is 15.9 cfs. The post-developed peak flow is below the pre-developed peak at the 100 year storm event and does not create any issues for downstream properties. INTRODUCTION This storm water drainage report is intended to determine the required detention to match pre- developed storm runoff conditions for the proposed Brazos Valley Floor and Design. The entire Gessner Engineering G 5 drainage area contributes to the drainage ditch along N. Graham Road. The point of contribution to the ditch was used for both pre-developed and post-developed conditions analysis. Drainage Calculations for this site were prepared according to the National Resource Conservation Method as detailed in Technical Release 55 (TR-55) published in June of 1986. Proposed improvements include a 15,000 SF building and 50,130 SF concrete pavement and approximately 8,140 SF of detention area. Curve numbers from TR-55 were used based on developed uses as described above. Pre-developed flows were calcu lated based on the existing development for the subject site and based on undeveloped conditions for the Carpet Outlet tract. The calculated pre- developed and developed flows include the two (2), five (5), ten (10), twenty-five (25), fifty (SO) and one-hundred (100) year storms in accordance with the Bryan/College Station Unified Stormwater Design Guidelines. CALCULATIONS Calculations were performed according to the USDA TR-55 and with the aid of HEC-HMS 3.5 by the U.S. Army Corps of Engineers. The output data from HEC-HMS has been provided as Appendix E. Time of Concentration The time of concentration (travel time) for each drainage area was estimated by summing the flow time for each segment of travel. For sheet flow, travel time was estimated by Manning's Kinematic equation: 0.007 x (nL )°"8 t =--~=~ I S0.4 ,JP; Where: tt = travel time (hours) n = manning's roughness coefficient L = flow length (feet) s = slope (ft/ft) P2 = 2-year, 24 hour rainfall (inches) For shallow concentrated flow, the travel time was calculated from the flow velocity based on the slope in the direction of flow. These velocities were taken from Table C-4 of the Bryan College Station Unified Stormwater Design Guidelines. Gessner Engineering G 6 The computed times of concentration for each drainage area are included in Appendix E. Computed values were increased to a minimum time of six (6) minutes as required, based on Chapter 3 of TR-55 which limits the minimum Time of Concentration to 0.1 hour or six (6) minutes. Unit Hydrograph A generic unit hydrograph was computed by distributing the rainfall depths (Table 1) according to the distribution factors for the NCRS Type Ill 24 hour storm. This hydrograph was then applied to each subarea based on the curve number and time of concentration of that area. Reach Routing Hydrographs were routed from subareas to the outflow through the kinematic wave method. This method allows for hydrographs to be translating with time, but not attenuating. The effects of backwater flow and pressure flow in channels were neglected. Peak Runoff Flow Peak Runoff Flow from the site was determined based on the Type Ill 24 hour storm applied to each drainage area. The depth-duration-intervals for each frequency are included in Table 1 below, and were obtained from Table C-6 in the Unified Stormwater Design Guidelines. Curve Number values (CN) were determined from Table C-7, Appendix C of the Unified Stormwater Design Guidelines. Peak pre-developed flows for the subject site adjacent to N. Graham Road are included in Table 1. Drainage areas and calculations are included on sheet CS.O and CS.1, which are attached in Appendix C. Rainfall Depth (in), 24-hr Pre-Developed Peak Flow Frequency duration (cfs) 2 year 4.50 5.6 10 year 7.40 10.4 25 year 8.40 12.5 50 year 9.80 14.1 100 year 11.00 16.3 Table 1: Rainfall Depths and Resulting Flows Peak Post-Developed Runoff Flow The post-developed peak flows compared to the pre-developed peak flows are shown in Table 2 below for each storm event. Hydrographs for each storm event are included as Appendix D. Gessner Engineering G 7 Pre-Developed Post-Developed Post-Developed Total Post- Storm Peak Flow at Peak Flow at Peak Flow at Developed Flow Event Southwest Outlet Southwest Outlet North Outlet (cfs) (cfs) (cfs) (cfs) 2 year 5.6 5.4 0.1 5.5 10 year 10.4 9.5 0.1 9.6 25 year 12.5 11.3 0.1 11.4 50 year 14.1 12.8 0.2 13.0 100 year 16.3 14.7 0.2 14.9 Table 2: Pre-Developed and Post-Developed Site Outflows CONCLUSION Based on visual evidence, engineering drainage calculations and sound engineering judgment, Gessner Engineering believes that the post-development flows are reduced for the two {2}, ten {10), twenty-five {25), fifty {SO), and one hundred (100) year design storms for this development, and do not create adverse impacts to downstream properties. Work Certification "This report for the drainage design of the Brazos Valley Floor & Design was prepared by me in accordance with the provisions of the Bryan/College Station Unified Drainage Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued." Licensed Professional Engineer State of Texas No . 98398 Gessner Engineering 8 APPENDIX A: General Location Map G ----~-------------------GessnerEngineering 9 Gessner Engineering 10 APPENDIX 8: FEMA 100 Year Floodplain Map G ------------------~-----GessnerEngineering 95000 FT ributary 10. BRAZOS COUNTY UNINCORPORATED AREAS 481195 Hopes Creek Tributary JO 30° 33· 45" L~~-2~-----_.c:.~-----_&:~~--t~-~-_.ll'--1 96° 18' 45" 00 0 MAP SCALE 1" = 1000' 1000 PANEL 0310E FIRM FLOOD INSURANCE RATE MAP BRAZOS COUNTY, TEXAS AND INCORPORATED AREAS PANEL 310 OF 475 (SEE MAP INDEX FOR FIRM PANEL LAYOUl) ~ ~ BRAZOS COUNTY COLLEGE STATION CITY QI' 4'111~ 480003 0310 0310 Notice to User: The Map Number shown below should be used when placing map orders: the Community Number shown above should be used on Insurance applications for the subject community. MAP NUMBER 48041C0310E MAP REVISED MAY 16, 2012 Federal Emergency M1m11gemcnt Agency This Is an oflicial copy of a portion of the above referenced need map. It was extracted using F-MIT On-Line. This map does not renect changes or amendments which may have been made subsequent to the date on the title block. For the latest product information about National Flood Insurance Program need maps check the FEMA Flood Map Store at www.msc.fema.gov 11 APPENDIXC: Drainage Area Maps and Calculations Gessner Engineering 12 APPENDIX D: Hydrographs G Subbasln 'PRE -AREA 1" Results for Run "PRE -2 YEAR" 0.001---,---:----'!'lll-- I j I 0.01-<---~--l -t-I 0.02 -----·-j _ _ l-..... ~-----.J o.os~---~------------------~---~----~---~ s~~~~~~l ~~~~~I ~ 5 2 l i t I I I l I I t- I i. I --1 -1 r ol---~---.-~-====;::::::=__J_ __ -+----=====:j======±=====~ 13 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :00 00:0( I I Legend {Compu~TllllC: 07Apr2014, 15:22:31) -Run:PRE - 2 YEAR Element:PRE -AREA 1 Resull:Precipttation -Run:PRE -2 YEAR Element: PRE -AREA 1 Resuft:Precipttation Loss --Run: PRE - 2 YEAR Element: PRE -AREA 1 Resutt:OlAflow ---Run:PRE -2 YEAR Element:PRE -AREA 1 Resuft:Baseflow Gessner Engineering G Subbasin "PRE -AREA 1' Results for Run "PRE -10 YEAR" 0.00 1 ---1----""."'"----i ..... _ _L --·~-0.02 0.04 I I I -----!-------<• ! o.06-1----_ __, 1 ____ __,. ____ __,__ O.OB -+------,, _____ ----------•-----1------+------+------:t 0.10-<------'-----·,._-----+----·-----;-----1------1-------jj 0.12-'-------'--------------------'---------'-------------'------' 12~----~---------------------------------~ I I 10 8 6 4 2 06:00 09:00 -Run:PRE -10 YEAR Element: PRE -AREA 1 Result:Precipttalion --Run:PRE -10 YEAR Element: PRE -AREA 1 Result: Outflow 12:00 01Jan2013 15:00 18:00 21 :DO -Run:PRE -10 YEAR Element:PRE -AREA 1 ResiJt:Precipttalion Loss - --Run: PRE -10 YEAR Element: PRE -AREA 1 ResiJt:Baseflow 00:0( I 14 Gessner Engineering 15 Subbasin "PRE -AREA 1' Results for Run "PRE -25 YEAR" 0.00 I I 0.02 I 0.04 :§: 0.06 I s= I c. Q) O.OB -----r-0 0.10 0.12 I I -··---- t --1 __ _ I ___ i ___ _,. 14 I 12 I 10 f B ~ ~ 6 0 I u: 4 r 2 0 ~If I r l I r I r 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:0( I 01Jan2013 I L~ {Compute Time: 07Apr2014, 15:22:31) -Run:PRE -25 YEAR Element: PRE -AREA 1 Result:Precipttation -Run:PRE -25 YEAR Element: PRE -AREA 1 Resl.«:Precipill!iion Loss --Run:PRE -25 YEAR Element: PRE -AREA 1 Result: Outflow ---Run: PRE -25 YEAR Element: PRE -AREA 1 RestJI: Base flow G Gessner Engineering G 0.00 0.02 0.04 '2 0.06 = ~ 0.08 Ol 0 0.10 0.12 0.14 0.16 16 14 12 10 ~ 8 ~ ~ 0 u: 6 Subbasin "PRE -AREA 1" Results for Run "PRE -50 YEAR" . -: I ... J --1------------~ -t· T I --T---~--_-~~ -i· __ =i+---~-t---1-· ---~---+--t __ , --~,--II----"-----I ____ L_~I _ I I r i I -----i---1 --~ ----i= ~-~- I -r __j J ____ L __ _ I I - 4 I r 2-1--___,_ _ _..._I __ 16 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :00 00:0( I -Run:PRE -SO YEAR Element:PRE -AREA 1 Resul:Precipltation -Run: PRE -SO YEAR Element: PRE -AREA 1 ResUt:Precipltation Loss --Run:PRE -SO YEAR Element:PRE -AREA 1 Result:Outflow - - -Run: PRE -SO YEAR Element:PRE -AREA 1 Result:Beseflow Gessner Engineering G 17 Subbasin "PRE -AREA 1" Results for Run "PRE -1 DD YEAR" o.oor---1----~----••• 1 o.02 r t I 0.04 l l J 0.06 -L ---I ~0.00 I ----------FlL 1 0.10 ~ -------·----~:~~~=-·-_-_-_ -_l-·--=--1 --0.12 0.14-1---------;----------- 0.16-1------------'----------------+-----+---·---'-------11 0.18-'------------'--------'--------'--------'--------'--------'------..........-" ::=------i---1 -----,-----..,...-1 -~1 ----. 12 I . ' r· 10 L_ ___ L __ I I l ,- ~-----1- 2-+-------+-------+---- 6 4 ol--~-.-~=====r=======:=-.---+----L--=:=:==:;======i======d 00:00 03:00 06:00 09:00 12:00 01Jan2013 15:00 18:00 21 :OD 00:0( I I Legend (Compute Trne: 07Apr2014, 15:22:30) -Rtsi:PRE -100 YEAR Elemenl:PRE. AREA 1 Result:Precipilation -R1.n: PRE -1 00 YEAR Element PRE -AREA 1 Result: Precipttation Loss --RtnPRE. 100 YEAR Element: PRE -AREA 1 Result: Outflow ---R1.n:PRE -100 YEAR Element: PRE -AREA 1 Result:Baseflow Gessner Engineering Junction "SOUTHWES T OUTLETti Resuns for Run "POST ... 2 YEAR• 6 · 5 4 -~3 v -s: 0 LL 2 1 o -1--------.--=sl~~~~~~~~~~~~ 00:00 03:00 06 :00 09:00 12:00 15:00 18:00 21:00 00:0 I 01Jan2013 LeQend (COfnPlte Tine: 06May20 15, 09:59:25) --Run: POST -2 YEAR Element SOUTHWEST OUTLET Result Outflow ---Run : POST. 2 YEAR ElementReach-2 ResultOutflow · • · · · -Run : POST - 2 YEAR Element: POST -AREA 3 Resul . Outflow -·-· Run :POST-2 YEAR ElementPOST -AREA4 Resu Outflow I 18 G ----------~-------------GessnerEngineering Junction ·soUTHWEST OUTLET0 R,esults for Run -POST -1 o YEAR'' 10 9 8 7 6 . -.fil 5 ' u ....... ~ ..Q 4 LL 3 2 1 0 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:0 I 01Jan2013 I LeQend (C~e rme: 06May201S, 10:02:54) --Run:POST-10 YEAR Element:SOUTHWEST OUTLET ResultOutflow ---Run:POST -10 YEAR ElementReach--2 ResultOutflow ·--··-Run.POST-10 YEAR Elenie11LPOST -AREA 3 ResulLOutflovv ---· Run:POST-10 YEAR ElementPOST-AREA4 ResultOutflow 19 20 Junction "SOUTHWEST OUTLET" Results for Run "POST -50 YEAR" 14 12 10 • 8 ......... J!! u -6 ~ lJ... 4 ? -0 -- 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:0 I 01Jan2013 I Leqend (Compute Tine: 06May201S, 10:04:54) --------Run:POST -50 YEAR ElementSOLITI-f\NE:ST OUTLET ResultOutflow ---Run : POST -50 YEAR ElementReach-2 Resu Outflow ------Run:P03T-GO YEAR ElementPO$T-AREA 3 Re~uttOutflow -·-· Run :POST -50 YEAR ElementPOST-AREA4 ResultOutflow G ----~-------------------GessnerEngineering 21 APPENDIX E: HEC-HMS Calculations G ~PRE-AREA 1 Pre-Developed HEC-HMS Model Project: 11-0355 Simulation Run: PRE -2 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Trne: 18Mar2014, 11:31:25 Basin Model: 11-0355 PRE Meteorologic Model: 2 YR Control Specifications: Control 1 Show Elements: I All Elements .., j Volume Units: @ IN t) AC-FT Sorting: [ Hydrologi~ ... ] Hydrologic Drainage Area Peak. Discharge Time of Peak Volume Element (MI2) (CFS) (IN) PRE -AREA 1 0.0037 5.6 O lJan.2013, 12: 16 3.19 Project: 11-0355 Simulation Run: PRE -10 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00~00 Compute Tune: 18Mar2014, 11:32:38 Basin Model: 11-0355 PRE Meteorologic Model: 10 YR Control Specifications: Control 1 Show Elements: [All Elements .., ] Volume Units: @ IN G AC-FT Sorting: [Hydcologic ... ] Hydrologic Drainage Area Peak Discharge Time of Peak Volume Element (MI2) (CFS) (IN) PRE-AREA 1 0.0037 10.4 01Jan2013, 12:16 6.07 Project: 11-0355 Simulation Run: PRE -25 YEAR Start of Run: OlJan.2013, 00:00 End of Run: 03Jan2013, 00:.00 Compute Tiilie: 18Mar2014, 11:32: 58 Basin Model: 11-0355 PRE Meteorologic.Model: 25 YR Control Specifications: Control l Show Elements: [All Elements ... J Volume Units: o IN C) AC-FT Sorting:. [ Hydrologic ... J Hydrologic Drainage Area Peak Discharge Tune of Peak Volume Element (MI2) {CFS) (IN) PRE -AREA 1 0.0037 12.5 01Jan2013, 12: 16 7.34 22 Gessner Engineering G Project: 11-035 5 Simulation Run: PRE -50 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03Jan2013, 00:00 Compute Tune: 18Mar2014, 11:34:.27 Basin Model: 11-035 5 PRE Meteorologic Model: 50 YR Control Specifications: Control 1 Show Elements: I All Elements ,.. I Volume Units: @ IN () AC.ff Sorting: [ Hydrologic .. j Hydrologic Drainage Area Peak Disdlarge lime of Peak Volume Element (MI2) (CFS) (IN) PRE-AREA 1 0.0037 14.1 01Jan2013, 12:16 8.32 Project: 11-0355 Simulation Run: PRE-100 YEAR Start of Run: 01Jan2013, 00:00 End of Run: 03.Jan2013, 00:00 Compute Time: 18Mar2014, 11:34:45 Basin Model: 11-0355 PRE Meteorologic Model: 100 YR Control Specifications: Control 1 Show Elemer1ts: I AD Elements .... ] Volume Units: ~ IN 0 AC.ff Sorting: [.Hy~ologic "!" J Hydrologic Drainage Area Peak Discharge Tune of Peak Volume Element (MI2} (CFS) (IN) PRE-AREA 1 0.0037 16.3 01Jan2013, 12:16 9.70 23 Gessner Engineering - 24 . POS~P OST -AREA2 POST ~AREA3 Post-Developed HEC-HMS Model G 25 Project: l 1 ·0355 SinUation Roo: POST • 2 VEAR 5t.or't of Run: Ol lan2013, 00:00 Bo51n Model: 11--0355 POST End of Rt.n: OZlarlZ013, 00:02 MeteoroloQic Model: 2 YR c~e rime:06May2015, 09:59:25 Control Speclk~:Control 1 Show EAements: Elem nts -.. Vobne lbt:s: o AC-FT SortfnQ: ,Hvci'olooic -. ) Hydrotoglc Or~/4/ea Peak Discharge Time ol Peak Volume Element (Mli) (0:5) (lN) POST -AAEA. 5 0.0012SOO 2.5 Ol lan2013, 12:08 3.31 POST· AA£A 6 .000953 2.1 Ollan2013, 12:09 J.91 POM> 1 .0009S"3 l.7 01lan2013, 12:15 J.91 Reach·l .000953 l.7 0J lan2013, 12:16 3.91 POllC2 0Jl02'2030 3.0 Ol.l¥l201S, 12' 19 3.58 Reach-2 0.0022030 3.0 0Jlan2013, 12:19 3.58 POST ·AREA3 0.0013750 2.4 01lan2013, 12: 13 3.51 POST MfA 1 .000125 0.2 01 J.;in...'>(113, 12: ()8 2.<16 SOUTHWEST OUTLET 0.0037030 5.1 OJJan2013, 12:1.5 3.52 POST • AREA 2 .00001733 o.o 01Jan2013, 12:07 4.26 POST -AAf.A, l .00001679 0.0 OJJan2013, 12:07 1.26 NORTH OUTLET .OOJ03-t1 2 0.1 Ollan2013, 12:07 1.26 Project : 11 ·0355 Sirrdatlon Rt.r'I! POST •. 10 VEAR 5br~ nfQ11n• nl1.-l\?n1 ~. M ·M End of R1.n: 02Jan2013, 00 :02 Compe.te Tine:06May20 15, 10:02:S1 RA<in MllMI, 1 I ./l.~Ci.1' Pf\~ Meteorologic Model: 10 YR Control SpecifkationS:Control l Hyaologit Dramoe Area Peak Discharge TmeolPeak Volu'ne Element (Ml2) (CFS) CIN) POST -AAf..A S 0.0012500 4.6 0Jlan2013, 12:08 6.25 POST· ARfA6 .000953 3.5 Otlan2013, 12:09 6.88 Pf'lN'J t -~ :u nnN\"11 ~. "' •~ F..AA :Reach-1 .000953 3.1 Olkn2013, 12:14 6.SS PON:>2 0.0022030 5.2 01Jan2013, 12:20 6.51 Rl!.!leh· 2 0.002'2030 5.2 Ol lan2013, 12:20 6.51 PQST· AREAJ O.OOJ37SO 4.3 OJJan2013, 12:13 6.H POST·AAEA1 .000125 0.4 Ol'.lan2013, 12:08 5 .15 SOUTHWEST OUTLET 0.0037030 <J.5 Ollan2013. 12: 15 6.44 POST · AREA2 .00001733 0.1 01lan2013, 12:07 7.25 P0St -AAEA 1 .00001679 0.1 01JanZQ13, 12:07 7.25 NORTH OUTLET .0000341 2 0 .. 1 OLlan.2013. 12:07 7.25 Gessner Engineering G Project: 11·0355 ~ation Rlr'I: POST· 25 VEAR st«t of Rl#'li Ol.lan2013, 00:00 8~1Modelr 11--0355 POST End of Run: 02Jan2013, 00:02 Meteorologic Model: 2S YR ~e Tme:06May2015, 10:03:37 Control Specifications:Control 1 Show Elemerts: r UE!ements ... I/oboe lklits: 0 1 AC-FT Sormg: ,.11)'1to&ogic "': Hydrolo<}c Drainage Area Peak Di$char9C nneot~ Vok.me Element (Ml2) (CFS) ' (IN) POST· AAEAS 0.0012500 s.s 01Jan2013, 12:08 7.52 PQST-AREA6 .OOQ9S3 4.2 01~13, 12:09 8.18 pON) 1 .000953 3.8 Ol.Jan2013, 12: 13 8.18 :Re«.h-1 .000953 3.8 01&"2013, 12:14 8.17 .PON' 2 o.00ZZ030 6 ,2 01)¥12(l13, 12:19 7,80 Readi-2 0.0022030 6.2 01Jao2013, 12:19 7.80 ;p<)ST • AREA 3 0.0013750 S.l Ollan2013, 12: 13 1.n f05T-AREA4 .000125 o.s 01~13, 12:07 6.37 ~THWEST OUTL£T 0.0037030 11 .3 Ollan2013, 12: 15 1.n PosT ·AAEA2 .00001733 0.1 Ol.lanZ013, 12:07 8.55 POST-AREA l .00001679 O.l 013¥r2013, 12:07 8.55 NOR TH OUTLET .00003412 0.2 Ol.lan2013, 12:07 8.55 Pro;ect: l t •.0355 SimWtioo Run: POST • SO VEAR Start of Run: 01Jan2013, 00:00 End of lhn: 02Jan2013, 00:02 C~e Tine:Cl6May201S, 10:04:51 Basin Model: 11 ·0355 POST Meteorolooic Model: 50 YR Control Specificotions:Control l --, S«tlng: Hydi<olo;ic .... '----_._.J ' --- ~oloQlc Ol'ainaqe Area p~ Disc:lwqe T~<i Peak Vobne Element (M12) (CFS) .. (TN) ------.. 01Jan20i3, 12:o8 8.si POST ·AA£A5 0.0012500 6.1 POST·AREA6 .000953 4.6 01Jan2013, 12:09 9.17 POM> l .000953 1.2 01~13, 12:13 9.17 Re«h-1 .000953 1.2 01Jan2013, 12: 11 9.17 POM>:2 0.0022030 7.0 01lan20.l3, 12: 19 8.79 Reach-2 0.002'2030 7.0 Ollan2013, 12: 19 8.79 POST • AA.EA 3 0.0013750 s.a 01Jan2013, 12:13 8.71 pOST· AREA4 .00012'5 0.6 01Jan2013, 12:~7 7.32 $0UTH\A/EST OUTLET 0.0037030 12.a 01.)an201J, 12: 15 8.71 POST-AAEA2 .00001733 0.1 01Jan2013, 12:07 9,55 POST -ARE.A t .00001679 0.1 01lan2013, 12:07 9.55 NORTH OUTLET .00003412 0.2 Ollan2013, 12:07 9.55 26 Gessner Engineering G Project: 11-0355 Simulation Run: POST • l 00 YEAR Start of Run: 01.lan2013, 00:00 fnd of lbrt: 02lan2013, 00~02 CQfYIPUte Time:OSMay20lS, 10:44:26 Basin Model: 11 ·0355 POST r ---~ Show Ele~: L Clcmct'lb· y J Hyd-objc l Orailage Area ~ (Ml2) POST ·AREAS 0.0012500 POST-AAEA6 .000953 PONO 1 .000953 Reach-1 .0009$3 POND2 0.0022030 Reach·2 0.0022030 POST·AAEA3 0.0013750 POST ·AREA4 .000125 SOUTHWEST OUTLET 0.0037030 POST·AREA 2 .00001733 POST-AREA l .00001679 NORTH OUTLET .00003412 Meteorologic Model: 100 YR Control Specfk.atlons:Control 1 AC-FT Peak Discharge · Timeof Peak (CFS) 7.1 Ollan20131 12:08 5.3 Ollan2013, 12:09 4.8 Ollan2013, 12: 1.3 4.6 01~13, 12: 14 8.0 Ollan20131 12: 19 8.0 Ollal'l2013. 12: 19 6.6 Ollan2013, 12: 13 0.7 Ollan2013, 12:07 14.7 01Jan20l3. 12: 15 0.1 Ol.Jan2013> 12:07 0.1 01J¥\Zo13, 12:07 0.2 Ollan2013, 12:07 Project: 1 l-0355 Slrrdation Rtri: post 100 year clogoed Reservoir: .PON) 2 Vok.lme (IN) 9.89 10.57 10.57 10.56 10.17 10.17 10.10 8.66 10.09 10.95 10.95 10.95 27 --!:=:" Jtoot o( ~uo. 01)ont0l'.J, Q0 ,00 End ol Run: 02Jan20l3, 00:02 Compute Tfme:06May20 15, 10:59:16 Oo~• MQdd. 11~ f'OST C~ O!it~ Meteorolocjc Model: 100 YR Control Specifications:Control l YolumoUnb; e IN AC-rT CompUted Reds Peak Inflow: 10.7 (CFS} oatefrrne r:I Pe.tr. Inflow: Ollan2013, 12:n Peak Discharge: 8.2 (CFS) DatefTime ct Peak.Disch¥ge:01Jan2013, 12:16 Inflow VoU'ne : 1.0. l 7 (IN) Peak storage: 0.2 (AC•FT) Dlsc:f'lar~ Volme: 10. l 1 (lN) Peak Elevation: 2.-'f (FT)\ Post-Developed Clogged Orifice Condition Gessner Engineering 28 APPENDIX F: Driveway Culvert Calculations G --------~~----~--~---~--GessnerEngineering HY-8 Culvert Analysis Report Crossing Discharge Data Discharge Selection Method: Specify Minimum, Design, and Maximum Flow Minimum Flow: 0 cfs Design Flow: 5.1 cfs Maximum Flow: 10 cfs Table 1 -Summary of Culvert Flows at Crossing : 11-0355 driveway culvert Headwater Elevation Total Discharge (cfs) Culvert 2 Discharge Roadway Discharge Iterations (ft) (cfs) (cfs) 320.06 0.00 0.00 0.00 1 1.#R 1.00 1.00 0.00 1 321.31 2.00 2.00 0.00 1 320.41 3.00 3.00 0.00 1 320.46 4.00 4.00 0.00 1 320.51 5.00 5.00 0.00 1 • 320.60 7.00 7.00 0.00 1 320.64 8.00 8.00 0.00 1 320.68 9.00 9.00 0.00 1 320.71 10.00 10.00 0.00 1 32 1.50 37.88 37.88 0.00 Overtopping Rating Curve Plot for Crossing: 11-0355 driveway culvert ~ ......, :t:;.. 321 .6 321 .4 c 321 .2 0 i 321.0 w © 320.8 ......, m ~ 320.6 m Q) I 320.4 320 .2 Total Rating Curve Crossing: 11-0355 driveway culvert 320 .0 r----~i-m ............................................................................... ... 0 5 10 15 20 25 Total Discharge (cfs) 30 35 Table 2 -Culvert Summary Table: Culvert 2 Total Culvert Headwater Inlet Control Outlet Flow Normal Critical !outlet Depth Tailwater Outlet Tailwater Discharge Discharge Elevation (ft) Depth (ft) Control Type Depth (ft) Depth (ft) (ft) Depth (ft) Velocity Velocity (cfs) (cfs) Depth (ft) (ft/s) (ft/s) 0.00 0.00 320.06 0.000 0.000 0-NF 0.000 0.000 0.000 0.000 0.000 0.000 1.00 1.00 1.#R 0.497 o.o• 3-M1t 0.016 0.014 0.198 0.198 0.381 0.842 2.00 2.00 321.31 0.517 1.252 3-M1t 0.031 0.028 0.284 0.284 2.342 1.027 3.00 3.00 320.41 0.346 0.079 1-S2n 0.047 0.336 0.311 0.349 0.758 1.150 4.00 4.00 320.46 0.402 0.131 1-S2n 0.063 0.389 0.357 0.401 0.893 1.243 5.00 5.00 320.51 0.449 0.177 1-S2n 0.079 0.433 0.396 0.447 1.020 1.320 5.10 5.10 320.51 0.454 0.181 1-S2n 0.080 0.437 0.393 0.451 1.048 1.327 7.00 7.00 320.60 0.539 0.255 1-S2n 0.110 0.514 0.464 0.524 1.249 1.444 8.00 8.00 320.64 0.579 0.288 1-S2n 0.126 0.551 0.487 0.558 1.371 1.495 9.00 9.00 320.68 0.618 0.320 1-S2n 0.142 0.585 0.521 0.590 1.460 1.542 10.00 10.00 320.71 0.655 0.349 1-S2n 0.157 0.617 0.549 0.619 1.557 1.585 *Full Flow Headwater elevation is below inlet invert. Straight Culvert Inlet Elevation (invert): 320.06 ft, Outlet Elevation (invert): 319.79 ft Culvert Length: 54.00 ft, Culvert Slope: 0.0050 Water Surface Profile Plot for Culvert: Culvert 2 Crossing -11-03 5 5 driveway culvert, Design Discharge - 5 .1 cfs Culvert -Culvert 2, Culvert Discharge -5.1 cfs 338 336 334 ~332 c 330 0 ~ 328 Q) w 326 324 322 320 -10 0 10 20 30 Site Data -Culvert 2 Site Data Option: Culvert Invert Data Inlet Station : 0.00 ft Inlet Elevation: 320.06 ft Outlet Station: 54 .00 ft Outlet Elevation: 319.79 ft Number of Barrels: 1 Culvert Data Summary -Culvert 2 Barrel Shape: Circular Barrel Diameter: 18.00 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: 0.0120 Culvert Type: Straight Station (ft) Inlet Configuration: Mitered to Conform to Slope Inlet Depression: NONE 40 50 60 70 Table 3 -Downstream Channel Rating Curve (Cross ing: 11-0355 driveway culvert) Flow (cfs) Water Surface Depth (ft) Velocity (ft/s) Shear (psf) Froude Number Elev (ft) 0.00 319.79 0.00 0.00 0.00 0.00 1.00 319.99 0.20 0.84 0.06 0.38 2.00 320.07 0.28 1.03 0.09 0.40 3.00 320.14 0.35 1.15 0.11 0.42 4.00 320.19 0.40 1.24 0.13 0.42 5.00 320.24 0.45 1.32 0.14 0.43 5.10 320.24 0.45 1.33 0.14 0.43 7.00 320.31 0.52 1.44 0.16 0.44 8.00 320.35 0.56 1.50 0.17 0.44 9.00 320.38 0.59 1.54 0.18 0.45 10.00 320.41 0.62 1.59 0.19 0.45 Tailwater Channel Data -11-0355 driveway culvert Tailwater Channel Option: Trapezoidal Channel Bottom Width: 4.00 ft Side Slope (H:V): 10.00 (_:1) Channel Slope: 0.0050 Channel Manning's n: 0.0350 Channel Invert Elevation: 319. 79 ft Roadway Data for Crossing: 11-0355 driveway culvert Roadway Profile Shape: Constant Roadway Elevation Crest Length: 50.00 ft Crest Elevation: 321.50 ft Roadway Surface: Paved Roadway Top Width: 38.00 ft 29 AppendixG: Technical Design Summary Gessner Engineering SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY The Cities of Bryan and College Station both require storm drainage design to follow these Unified Stormwater Design Guidelines. Paragraph C2 of Section Ill (Administration) requires submittal of a drainage report in support of the drainage plan (stormwater management plan) proposed in connection with land development projects, both site projects and subdivisions. That report may be submitted as a traditional prose report, complete with applicable maps, graphs, tables and drawings, or it may take the form of a ''Technical Design Summary". The format and content for such a summary report shall be in substantial conformance with the description in this Appendix to those Guidelines. In either format the report must answer the questions (affirmative or negative) and provide, at minimum, the information prescribed in the ''Technical Design Summary" in this Appendix. The Stormwater Management Technical Design Summary Report shall include several parts as listed below. The information called for in each part must be provided as applicable. In addition to the requirements for the Executive Summary, this Appendix includes several pages detailing the requirements for a Technical Design Summary Report as forms to be completed . These are provided so that they may be copied and completed or scanned and digitized . In addition, electronic versions of the report forms may be obtained from the City. Requirements for the means (medium) of submittal are the same as for a conventional report as detailed in Section Ill of these Guidelines. Note: Part 1 -Executive Summary must accompany any drainage report required to be provided in connection with any land development project, regardless of the format chosen for said report. Note: Parts 2 through 6 are to be provided via the forms provided in this Appendix. Brief statements should be included in the forms as requested, but additional information should be attached as necessary. Part 1 -Executive Summary Report Part 2 -Project Administration Part 3 -Project Characteristics Part 4 -Drainage Concept and Design Parameters Part 5 -Plans and Specifications Part 6 -Conclusions and Attestation STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT Part 1 -Executive Summary This is to be a brief prose report that must address each of the seven areas listed below. Ideally it will include one or more paragraphs about each item. 1. Name, address, and contact information of the engineer submitting the report, and of the land owner and developer (or applicant if not the owner or developer). The date of submittal should also be included. 2. Identification of the size and general nature of the proposed project, including any proposed project phases. This paragraph should also include reference to STORMWATER DESIGN GUIDELINES Effective February 2007 Page 1 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY applications that are in process with either City: plat(s), site plans, zoning requests, or clearing/grading permits, as well as reference to any application numbers or codes assigned by the City to such request. 3. The location of the project should be described. This should identify the Named Regulatory Watershed(s) in which it is located, how the entire project area is situated therein, whether the property straddles a watershed or basin divide, the approximate acreage in each basin, and whether its position in the Watershed dictates use of detention design. The approximate proportion of the property in the city limits and within the ET J is to be identified, including whether the property straddles city jurisdictional lines. If any portion of the property is in floodplains as described in Flood Insurance Rate Maps published by FEMA that should be disclosed. 4. The hydrologic characteristics of the property are to be described in broad terms: existing land cover; how and where stormwater drains to and from neighboring properties; ponds or wetland areas that tend to detain or store stormwater; existing creeks, channels, and swales crossing or serving the property; all existing drainage easements (or ROW) on the property, or on neighboring properties if they service runoff to or from the property. 5. The general plan for managing stormwater in the entire project area must be outlined to include the approximate size, and extent of use, of any of the following features: storm drains coupled with streets; detention I retention facilities; buried conveyance conduit independent of streets; swales or channels; bridges or culverts; outfalls to principal watercourses or their tributaries; and treatment(s) of existing watercourses. Also, any plans for reclaiming land within floodplain areas must be outlined. 6. Coordination and permitting of stormwater matters must be addressed. This is to include any specialized coordination that has occurred or is planned with other entities (local, state, or federal). This may include agencies such as Brazos County government, the Brazos River Authority, the Texas A&M University System, the Texas Department of Transportation, the Texas Commission for Environmental Quality, the US Army Corps of Engineers, the US Environmental Protection Agency, et al. Mention must be made of any permits, agreements, or understandings that pertain to the project. 7. Reference is to be made to the full drainage report (or the Technical Design Summary Report) which the executive summary represents. The principal elements of the main report (and its length), including any maps, drawings or construction documents, should be itemized. An example statement might be: "One -page drainage report dated one set of construction drawings sheets) dated , and a ----page specifications document dated comprise the drainage report for this project." STORMWATER DESIGN GUIDELINES Effective February 2007 Page 2 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DES IGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) Enginee ring and Design Professionals Information Engineering Firm Name and Address: Jurisdiction Gessner Engineering City: Bryan 2501 Ashford Drive Suite 102 x College Station College Station, TX 77840 Date of Submittal: Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: Jeremy N. Peters, 979-680-8840, jpeters@gessnerengineering.com Supporting Engineering I Consulting Firm(s): Other contacts: Developer I Owner I Applicant Information Developer I Applicant Name and Address: Phone and e-mail: Chuck Moreau -Moreau Family Investments, Ltd . 764-4084 1834 Harris Drive chuck@bvcarpetoutlet.com College Station, TX 77845 Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: Project Identification Development Name: Brazos Valley Floor and Design Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? Site Project If multi-phase, subject property is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) Lot 1 O, Block 1, Rock Prairie West Business Park If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. General Location of Project Area, or subject property (phase): Rock Prairie & Wellborn In City Limits? Bryan: acres. College Station: 2.38 acres. STORMWATER DESIG N GUIDELINES Effective February 2007 Extraterritorial Jurisdiction (acreage): Bryan: College Station: Acreage Outside ET J: Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, pl atted land, or built subject property: developments: N. Graham Rd., Old Wellborn Rd . Named Regulatory W atercourse(s) & Watershed(s): Tributary Basin(s): Plat Information For Project or Subject Property (or Phase) Preliminary Plat File#: Final Plat File#: Date: Name: Status and Vol/Pg: If two plats, second name: Fi le#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: PPD l(x~)iA~ or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Preliminary Report Required? No Submittal Date Review Date Review Comments Addressed? Yes --No --In W ri ting? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 201 2 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation descri bing and substantiating any agreements, understandings, contracts, or approvals. Coordination Dept. Contact: Date: Subject: With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? Yes No X -- Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No X -- Coordination with Summarize need(s) & actions taken (include contacts & dates): T AMUS Needed? Yes No x -- -- Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective in spaces below. Entity Permitted or Approved? US Army Crops of Engineers No x Yes --- US Environmental Protection Agency No x Yes --- Texas Commission on Env ironmental Quality No x Yes ---- Brazos River Authority No x Yes --- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 Status of Actions (include dates) APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Site _X_ Redevelopment of one platted lot, or two or more adjoining platted lots. Development __ Building on a single platted lot of undeveloped land. Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ Construction of streets and utilities to serve one or more platted lots. Development __ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of Construction of new parking lot for existing building and construction of new Pro~osed 12,000 SF warehouse Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No Yes -- -- FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I No _X __ Yes __ (Section II, Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain I No _X __ Yes Rate Map area of a FEMA-regulated watercourse? -- Encroachment( s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No x -- Yes -- If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -ProQert~ Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (&date) here, and attach copy if not already in City files. -- Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi-phase project, describe stormwater management x plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? _X __ No --Yes Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? _X_ No --Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) _x __ Detention is required. --Need must be evaluated. __ Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECH NICAL DES IGN SUMMARY Part 3 -Pro~erty Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? x No Yes If yes, --describe spli ts below. In Part 4 describe design concept for handling this. Watershed or Basin Larger acreage Lesser acreage Above-Project Areas(Section II, Paragraph 83-a) Does Project Area (project or phase) receive run off from upland areas? _X _ No --Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? --No --Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? x No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Property Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage easements exist for any part of pathway(s)? X No Yes If yes, for what part of length? % Created by? __ plat, or instrument. If instrument(s), describe their provisions. Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Pathway Areas Nearby Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Detention pond on adjacent property. Drainage t----------------------------------i Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? _x_ No __ Yes If yes, explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 ------------------------' SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No Yes Separate Instrument? x No Yes ---- Per Guidelines reference above, how will __ Establi shing Easements (Scenario 1) runoff be discharged to neighboring _x_ Pre-development Release (Scenario 2) property(ies )? Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# ) Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) detention Combination: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? documentation. STORMWATER DESIGN GUIDELIN ES Effective February 2007 No Page 10 of 26 --Yes Explain and provide APPENDIX. D: TECH . DESIGN SUMMARY As Revised August 201 2 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result in shifting runoff between Basins or Identify gaining Basins or Watersheds and acres shifting: !----------------------------~ between Watersheds? What design and mitigation is used to compensate for increased runoff from gaining basin or watershed? X No Yes How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 1. __ With facility(ies) involving other development projects. 2. _x __ Establishing features to serve overall Project Area. 3. __ On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit# ) Two detention ponds; one located to the southwest of the proposed building and one to the northwest of the building. 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. C'· 't:l Q) (/) c Q) § >-a:: (/) c Ol ·;n Q) 0 Oz Are aquatic echosystems proposed? _x___ No __ Yes In which phase(s) or project(s)? Are other Best Management Practices for reducing stormwater pollutants proposed? _x_ No __ Yes Summarize type of BMP and extent of use: If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. __ Detention elements __ Conduit elements __ Channel features __ Swales __ Ditches __ Inlets __ Valley gutters __ Outfalls __ Culvert features __ Bridges ________ Other STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revi sed August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No _X __ Yes Identify type and general size and In which phase(s). Culvert under drive at SW of the Proposed Building. If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): Property is served by two detention ponds ; one to the NW and one to the SW of the proposed building. Pond 1 discharges into Pond 2 which discharges to SW of site . Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? __ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? I Surfaces? C'· "O (l.J C/J Steepest side slopes: Usual front slopes: Usual back slopes: C/J :::i (l.J C/J >- (l.J I .L: Flow line slopes: least Typical distance from travelway: () -'6 typical (Attached Exhibit# ) (l.J 0 greatest :2 C/J z ] xi Are longitudinal culvert ends in compliance with B-CS Standard Specifications? .._ Yes No, then explain: < C/J At intersections or otherwise, do valley gutters cross arterial or collector streets? .n (l.J No Yes If yes explain: :s C'· >---() "O I .L: (l.J -C/J ·-:::i ::: .._ Are valley gutters proposed to cross any street away from an intersection? C/J (l.J Ci) =§ 0 No Yes Explain: (number of locations?) ~ OlZ -- -- en "O I (l.J c .._ (IJ < x STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX . D: TECH . DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECH NICAL DESIGN SUMMARY Part 4 -Drainage Concegt and Design Parameters I Continued (Page 4.4) Stormwater Ma nagement Concept (continued) Within Or Serving Subj ect Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? --Yes --No If "no", identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? --Yes --No If no, explain where and why not. C-· "'O Cll (/) Will inlet size and placement prevent exceeding allowable water spread for 10-year ::J L... Cll design storm throughout site (or phase)? Yes No If no, explain. ------::J en "'O ~ c "'O co Cll Sag curves: Are inlets placed at low points? Yes No Are inlets and ..a E -- -- L... ·-conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? ::i -(.) c Yes No Explain "no" answers. ..c 8 -----~ -~ (/) Ci) Cll L... UJ Cll Will 100-yr stormflow be contained in combination of ROW and buried conduit on L... ~ whole length of all streets? Yes No If no, describe where and why. ---- Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes --No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? __ No --Yes Identify length(s) and where used. C-· "'O Pipe runs between system I Typical Cll (/) Longest (/) Cll access points (feet): ::J >- ii Are junction boxes used at each bend? --Yes --No If not, explain where and why. (/) c ·-0 ~z j xj Are downstream soffits at or below upstream soffits? Least amount that hydraulic (/) grade line is below gutter line .!!!. Yes No __ If not, explai n where and why: --(system-wide): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 201 2 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4-Drainage ConceQt and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) (iJ Describe watercourse(s), or system(s) receiving system discharge(s) below (!) (include design discharge velocity, and angle between converging flow lines). 0 c 1) Watercourse (or system), velocity, and angle? Cll Ui c (!) ...... -o al E 2) Watercourse (or system), velocity, and angle? :J ...... c 0 ·-'+-c . 0 .2 0 c -·--E <D .!!}_, 3) Watercourse (or system), velocity, and angle? <DE ~ ..... Cll (/) (/) ~(!) :J c :2 0 ·-> ~ e ""O a. E ..... For each outfall above, what measures are taken to prevent erosion or scour of ...... (!) 0 (!) receiving and all facilities at juncture? ..... ..c (/) (/) (!) 1) ..... Cll ...... Cll 2) a. (!) (/) c 3) .s Are swale(s) situated along property lines between properties? __ No --Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): C'-· (/) ..... (!) ~ (/) ..... (!) Flow line slopes (minimum and maximum): (/) >-c j I al 0 C/JZ Outfall characteristics for each (velocity, convergent angle, & end treatment). :J 1 xi (/) (!) ...... Will 100-year design storm runoff be contained within easement(s) or platted drainage <( ROW in all instances? --Yes --No If "no" explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 201 2 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters / Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? _x_ No __ Yes If so, provide the following: Ul <ll Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes No ..c: -- (.) Are top of banks separated from road shoulders 2 feet or more? Yes No ."'= ----0 Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No <ll -----a For any "no" answers provide location(s) and explain: "(jj -a Cll 0 0::: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: Ul <ll Is 100-year design flow contained in conduit/swale combination? >-Yes No ----I]' If "no" explain: c Space for 100-year storm flow? ROW Easement Width 0 Cll -z Ul Swale Surface type, minimum Conduit Type and size, minimum and maximum 1 ~ and maximum slopes: slopes, design storm: 0 ~ <:'-· '6 Ul -a Qi Cll Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c >-c Cll c ..c: Cll (.) .... cs <ll c Access Describe how maintenance access is provided (to swale, into conduit): Cl. 0 0 ·--'+--Cll 0 E ::i .... .~ s c c Instance 2 Describe general location, approximate length : <ll -a E <ll Cll Ul Ul ::i Ul <ll Is 100-year design flow contained in conduit/swale combination? Yes No c -a ·:;;: ----0 If "no" explain : ~ 0 .... c Cl. :.0 -<ll Space for 100-year storm flow? ROW Easement Width E <ll 0 ..c: (.) Ul Swale Surface type, minimum Conduit Type and size, minimum and maximum ."'= <ll -and maximum slopes: slopes, design storm: ::i Cll -a .... c Cll 0 Cl. Describe how conduit is loaded (from streets/storm drains, inlets by type): (.) <ll Inlets --Ul <ll co c :;; -S Ul <ll Access Describe how maintenance access is provided (to swale, into conduit): .... <( STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters J Continued (Page 4.7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length , surfacing: c «u E a. x 0 w I-'+- ti= ui Is 100-year design flow contained in swale? --Yes No Is swale wholly 0 Q) --c ,_I within drainage ROW? Yes No Explain "no" answers: :::J -- -- I- Q) > '(ii Access Describe how maintenance access is provide: u Q) I-0 ;<: z :::J "O 1 c 0 u Instance 2 Describe general location, approximate length, surfacing: "O Q) ·;:: ('· :::J (/) .0 c :5 Q) 0 E £ Q) (/) Is 100-year design flow contained in swale? Yes No Is swale whol ly ·~ co ----Q) within drainage ROW? __ Yes No Explain "no" answers: (/) I-Q) 0 -- (ii s ~ (/) 0 ~ 0:: Access Describe how maintenance access is provided: .S? 1:i :::J a. Instance 3, 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? --No Yes If only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. ('· "O c Will design replicate natural channel? Yes No If "no", for each instance Q) -----(/) co describe section shape & area, flow line slope (min . & max.), surfaces, and 100-year 0 a. a. x design flow, and amount of freeboard : 0 w I-a. Instance 1: (/) (/) -Q) c >-Q) E I Q) > Instance 2: 0 I-a. E 0 z (ii xi c Instance 3: c co ..c () STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concegt and Design Parameters I Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? x No Yes ----If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? _x_ Yes No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. ,....... 1:l Q) :::J c :;:::; Watercourses (and tributaries): Aside from fringe changes, are Regulatory c 0 Watercourses proposed to be altered? _x_ No __ Yes Explain below. ~ C/l c Submit full report describing proposed changes to Regulatory Watercourses. Address Q) existing and proposed section size and shape, surfaces, alignment, flow line changes, E Q) length affected, and capacity, and provide full documentation of analysis procedures > 0 and data. Is full report submitted? Yes No If "no" explain: L.. --Cl.. E - Qj c c ro All Proposed Channel Work: For all proposed channel work, provide information ..c u requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? Yes No If ---- not, identify location and explain: Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? 2 For each provide info. below. For each dry-type facilitiy: Facility 1 POND 1 Facility 2PQND 2 Acres served & design volume + 10% 0.61 ac 0.061 ac-ft 0.67 ac 0.165 ac-ft 100-yr volume: free flow & plugged 0.032 ac-ft 0.055 ac-ft 0.146 ac-ft 0.174 ac-ft Design discharge (10 yr & 25 yr) 3.1 cfs 3.8 cfs 5.2 cfs 6.2 cfs Spillway crest at 100-yr WSE? _x_yes --no _x _yes --no Berms 6 inches above plugged WSE? _x_yes --no _x __ yes --no Explain any "no" answers: Vl (].) >- 1 For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: 3.8 cfs, drainage structure with orifice and weir 0 z Facility 2: 6.2 cfs , drainage structure with orifice and weir I Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: _x_Yes No Facility 2: x Yes No ---- --C'-· If "no" explain: 'O (].) Vl 0 a. 0 -.._ 0... For each, what is velocity of 25-yr design discharge at outlet? & at spillway? '\ Vl ~ 13.22 fVsec & 4.38 tvsec Q) Facility 1: 4.75 fVsec & Facility 2: ~ -"-,., '(3 Are energy dissipation measures used? No __x_ Yes Describe type and cu -- LL location: c Riprap at discharge points 0 :;:::; c Q) -Q) 0 Q) For each, is spillway surface treatment other than concrete? Yes or no, and describe: .._ <l'. Facility 1: no, concrete weir Facility 2: no, concrete weir For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Riprap Facility 2: Riprap If berms are used give heights, slopes and surface treatments of sides. Facility 1: Pond 1: no berms, grass side slopes 10%-25% Pond 2: berm on plan north and west sides, 2.5' max. berm height, Facility 2: grass side slopes 16%-25% STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": Ul Facility 1; yes Ql :-=: ==~ ~ Ql Facility 2: yes LL ::J c c:.;:: 0 c :-=: 0 c (.) Ql -Qi For additional facilities provide all same information on a separate sheet. 0 Are parking areas to be used for detention? _x_ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? No x Yes If "yes", provide information in next two boxes. -- -- Will 25-yr. flow pass without flowing over driveway in all cases? x Yes No ---- Without causing flowing or standing water on public roadway? x Yes No ---- Designs & materials comply with B-CS Technical Specifications? _X_ Yes --No Explain any "no" answers: C-· Ul Ol c ·u; Are culverts parallel to public roadway ali gnment? _X_ Yes No Explain: Ul 0 --L.. Ul (.) Ql 2 >--~ I .!:-x Creeks at Private Drives: Do private driveways, drives, or streets cross drainage Cll ways that serve Above-Project areas or are in public easements/ ROW? -0 0 x No Yes If "yes" provide information below. Ql z ----Ul I ::J How many instances? Describe location and provide information below. Ul t:: Ql Location 1: .2: ::J (.) Ql Location 2: L.. <( Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNlCAL DESIGN SUMMARY Part 4 -Drainage Concegt and Design Parameters I Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulato~ Watercourses (&Tributaries): Are culverts proposed on these faciliti es? x No __ Yes, then provide full report documenting assumptions, --criteria, analysis, computer programs, and study fi ndings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: ,........ Arterial or Major Collector Streets: Will culverts serve these types of roadways? ..... Q) Q) x No Yes How many instances? For each identify the ..c: (/) ---- Q) location and provide the information below. ..... (/) co Instance 1: Q) .... >-g_ I ~ Instance 2: Instance 3: c 0 '.+:; Yes or No for the 100-year design flow: 1 2 3 0 co z E xii Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E <'-· co Is velocity limited per conditions (Table C-11 )? (/) (/) g1-o Explain any "no" answer(s): ·-c ~ co 0 c .... 0 (.) ·- >. cu co (.) ~ .2 -0 Q) co .!:l Minor Collector or Local Streets: Will culverts serve these types of streets? 0 ·-........ (.) (.) x No Yes How many instances? for each identify the ·-(/) -Q) -----§ -0 location and provide the information below: a. Q) ..... a. Instance 1: co c -0 >. Instance 2: Q) c ~ co ..... Instance 3: (/) 0 t:'. (/) Q) Q) For each instance enter value, or "yes" I "no" for: 1 2 3 .2: (.) ::::J c (.) co Design yr. headwater WSE 1 ft. below curb top? Q) ti .... c <! ·-100-yr. max. depth at street crown 2 feet or less? Q) .... 0 Product of velocity (fps) & depth at crown (ft)= ? E .... Is velocity limited per conditions (Table C-11 )? 0 ~ Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDI X. D: TECH. DESIGN SUMMARY As Revi sed August 201 2 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? Yes No If not, ----identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? __ No __ Yes If yes, identify location(s) and provide justification: ~ Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? ""CJ No Yes If "yes" identify location(s), describe outfall design treatment(s): <D ----::J c ~ 0 ~ (/) t <D Is scour/erosion protection provided to ensure long term stability of culvert structural ~ ::J components, and surfacing at culvert ends? __ Yes __ No If "no" Identify u locations and provide justification(s): Will 100-yrflow and spread of backwater be fully contained in street ROW , and/or drainage easements/ ROW? __ Yes --No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? _x_ No --Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? -(/) (i) OJ CJ ·;::: Cl'.l A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: £ Pollution Prevention construction entrance, erosion control silt fence, hay bales at co Plan (SW3P) pond discharge points :::J a established for ..... project construction? Q) co x s No Yes ---- Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? x No Yes If "yes" list general type and location below. -- -- Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? Yes --No If "no" explain: -- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements Channel features ---- Culvert features Swales Ditches Inlets Outfalls -- -------- __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology Yes No Is a map(s) showing all Design Drainage Areas provided? _x __ -- Briefly summarize the range of applications made of the Rational Formula: N/A. Rational Method can not be used for detention design per BCS Std. Design Guidelines. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? acres STORMWATER DESIGN GUIDELINES Effective February 2007 Location (or identifier): Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration , was segment analysis used? 100 No x Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? __ x_ No --Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall 2, 10, 25, 50, & 100 100 Detention facilities: outlet and conveyance structure(s) 2, 10, 25, 50, & 100 2, 10,25,50,& 100 Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: For conduit type(s) Coefficients: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? No Yes Head and friction losses No Yes -------- Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? --Yes --No Are elevation drops provided at inlets, manholes, and junction boxes? --Yes --No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? --Yes --No For 100-year flow conditions? --Yes --No Explain any "no" answers: What tai lwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? --Yes --No If "no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Effective February 2007 Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised August 2012 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version , any applicable patches and the publisher Part 5 -Plans and S~ecifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3 . Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signinq and sealinq below. ''This report (plan) for the drainage design of the development named in Part B was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage imorovements have been issued or fall under applicable general permits." liYii Licensed Professional Engineer State of Texas PE No. 98398 STORMWATER DESIGN GUIDELINES Effective February 2007 - ~ .... ~~,,~'"' . -~-\ti:OFtej.·\·\. ~-·~ ·•!·.•····· '!I. .,, . ""' •··. (··· 4!. . '·' ~ .. · ' .... ·~.. ;, .. , . ~·lfll. •• • . -........ ·1· .I'* . . • 'I: ,..... ·.. " . 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