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Home My WebLink About40 DP Benham National Bank 05-65 2407 Earl Rudder Fwy SCITY OF COLLEGE STATION Planning d-Development Strviets SITE LEGAL DESCRIPTION: Liberty Subdivision Lot2A DATE OF ISSUE: 02/03/06 OWNER: DEVELOPMENT PERMIT PERMIT NO. 05-65 FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE ADDRESS: 2470 Earl Rudder Freeway South DRAINAGE BASIN: Wolf Pen Creek VALID FOR 12 MONTHS CONTRACTOR: Brenham National Bank c/o Ronald Alfred P.O . Box 2568 Brenham , TX 77834 TYPE OF DEVELOPMENT: SPECIAL CONDITIONS: Full Development Permit All construction must be in compliance with the approved construction plans All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section 7 .5.E ., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance, prior to any operations of this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and required to remain is strictly prohibited . The disposal of any waste material such as, but not limited to, paint , oil , solvents, asphalt, concrete , mortar, or other harmful liquids or materials within the drip line of any tree required to remain is also prohibited . ******TCEQ PHASE II RULES IN EFFECT******NO WORK IN TXDOT ROW UNTIL UTILITY PERMIT APPROVED The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite , it is the contractors responsibility to implement measures that will meet City, State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state . The Owner and/or Contractor shall be responsible for any damage to adjacent properties , city streets or infrastructure due to heavy machinery and/or equipment as well as erosion , siltation or sedimentation resulting from the permitted work . In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction , erosion, and sedimentation shall not be deposited in city streets , or existing drainage facilities . I hereby grant this permit for development of an area outside the special flood hazard area . All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit application for the above named project and all of the codes and ordinances of the City of College Station that apply. Date Owner/ Agent/Contractor Date Brenham Bank -Engineer's Estimate (Public Infrastructure Only) February 2006 Item Description Unit Quantitll Unit Cost GENERAL ITEMS 1 Mobi lization LS 1 $ 790 .00 2 Trench Safety LF 26 $ 1.00 Subtotal WATER ITEMS 3 6" PVC Water Line C909 CL200 with Structural Backfill LF 26 $ 50 .00 4 6" x 12" MJ Tapping Sleeve & Valve EA 1 $ 1,200 .00 5 6" x 6" MJ Tee EA 1 $ 350 .00 6 Standard Fire Hydrant Assembly EA 1 $ 2 ,5 00 .00 7 6" MJ Gate Valve & Box EA 1 $ 550 .00 8 Connection to existing system EA 1 $ 2 ,000 .00 Subtotal 15% Contingency TOTAL Amount $ 790.00 $ 26 .00 $ 790.00 $ 1,300.00 $ 1,200.00 $ 350 .00 $ 2 ,500 .00 $ 550.00 $ 2 ,000 .00 $ 7,900.00 $ 1,303.50 $ 9,993.50 Brenham Bank -Engineer's Estimate (Public Infrastructure Only) February 2006 Item Description Unit Quantit~ Unit Cost GENERAL ITEMS 1 Mobilization LS 1 $ 790 .00 2 Trench Safety LF 26 $ 1 .00 Subtotal WATER ITEMS 3 6" PVC Water Line C909 CL200 with Structural Backfill LF 26 $ 50 .00 4 6" x 12" MJ Tapping Sleeve & Valve EA 1 $ 1,200 .00 5 6" x 6" MJ Tee EA 1 $ 350.00 6 Standard Fire Hydrant Assembly EA 1 $ 2,500 .00 7 6" MJ Gate Valve & Box EA 1 $ 550 .00 8 Connection to existing system EA 1 $ 2 ,000 .00 Subtotal 15% Contingency TOTAL Amount $ 790 .00 $ 26 .00 $ 790.00 $ 1 ,300 .00 $ 1 ,200 .00 $ 350 .00 $ 2 ,500 .00 $ 550 .00 $ 2 ,000.00 $ 7,900.00 $ 1,303.50 $ 9,993.50 EASEMENT DEDICATION SHEET To be filled In and submitted with construction plans and specifications for preliminary review (Not ,....._._,_,__ ____ ~--·--_ • .........,.,,, ACCOUNTNO.-=--....,....,~=-:-=:-;"'.-=t (For ordering title work, a..,_-..,.-~-_....___._.,,c.. _______ -'--_-..,.------l TYPE OF EASEMENT : __ Public Utilities (PUE) REVIEW AND APPROVAL REQUIRED Approval Required By : (please initial) ~ METES & BOUNDS DESCRIPTION C THIS SECTION TO BE COMPLETED BY APPLICANT PROPERTY OWNER(S): __ T~h~e .... B~r~en~h_a~m~N"-:":a,.,_t~io~n~a~I B~a...,..n.,....k_-..,,-~-----:..--....--r.,.-------- (Names must be e>eaetfY as tfleY appear on the deed) ADDRESS : P.O. Box 2568 PHONE NUMBER:_('"""9 ...... 7"""'9l'-"2""'"7 ...... 7-6-=--1 _..19._ ____ _ Brenham, TX 77834 ALL LENDERS (Please furnish copies of all lien documents): __ ___:.N.:..:o::....O=ut:.:::sc.:=ta:..:..n:..:::dc:.:.in'""'g._,L:.;:oo.:a"""'n_,,_s _________ _ (Names and Addresses) IF OWNER IS A CORPORATION, PARTNERSHIP, OR JOINT VENTURE (also see #5 below): 1. State of Incorporation/Registration _.T..,e=xa""s"------------------------ 2. Partners' Names (if applicable) -~N~/A ______________________ _ 3 . Person Authorized to Sign ___ .._.R~o""'"na=l=d~D'"". "'"A"'"lf__.re._..d'"'-'-P__.re._..s'"'id .... e'"'n..,,t .,..an__.d--=-C=E~O~----------- (Name and Title) I( 1. IA 2 . ~ 3 . ).. 4. '-5 . ;_ 6 . LEGAL DEPARTMENT MUST BE PROVIDED WITH THE FOLLOWING: (Please check items that are attached) A copy of a recent (within 90 days) deed or title insurance policy showing the names of the ~rantors/owners ; and For unplatted property, a signed, sealed and dated metes and bounds description and a diagram of the property showing the location of the easement ; or For platted property, a copy of the plat showing the lot, block , subdivision, and recording information . For blanket easements, a signed, sealed and dated metes and bounds description and a diagram of the property. Corporate or partnership owners must furnish a copy of a corporate resolution or other proof of authority to sign on behalf of the corporation, partnership, or joint venture . . Name, address and phone number of person who is to receive the easement and be responsible for getting 1t executed : Ronald Alfred, President and CEO for Brenham National Bank P .O. Box 2568 (979) 277-6119 Any land acquisition resulting from Capital Improvement Projects requires a meeting wfth the Legal Department . ~· DS ·U , FOR OFFICE USE ONLY P&Z CASE NO.: 05·~1~ DATE SUBMITIED: 11 1<rl{J5 LICATION ,~~~ C ITY OF COLLEGE S TATI ON Pla nning & Development Services SITE PLAN APP MINIMUM SUBMITTAL RE QUIREMENTS _L Site plan application completed in full. _L $200.00 Application Fee. _L $200.00 Development Permit Application Fee. _L $600.00 Public Infrastructure Inspection Fee if applica ble. (This fee is payable if construction of a public waterline, sewertine, sidewalk, street or drainage facili ties is involved.) _LEleven (11) folded copies of site plan _L One (1) folded copy of the landscape plan. _L One (1) copy of building elevation for all buildings. _L A list of building materials for all facades and screenin _L Color samples for all non-residential buildings . g for non-residential buildings. I buildings). N/A Traffic Impact Analysis (if applicable for non-residentia _LA copy of the attached site plan checklist with all items checked off or a brief explanation as to why they are not checked off. N/A Parkland Dedication requirement approved by the Pa rks & Recreation Board , please provide proof of approval (if applicable). Date of Preapplication Conference: October 3 2005 NAME OF PROJECT Brenham National Bank ADDRESS 2470 Earl Rudder Freeway South LEGAL DESCRIPTION Lot 2A. Block 1 . Liberty Subdivi~ion APPLICANT/PROJECT MANAGER'S INFORMATION (Primary C ontact for the Project): Name ~~~~~~~=M=it~ch~e~ll~&~M~or~g=a~n.~L=L~P~~~ Street Address: 511 University Drive East . Suite 204 State : TX Zip Code : 77840 Phone Number (979) 260·6963 PROPERTY OWNER 'S INFORMATION : Name David Jaeckles Street Address : 229 E. Wisconsin Ave .. Suite 600 E·M Fax City: College Station ail Address : v@.mitchellandmorgan.com Number (979} 260-3564 City : Milwaukee State : WI Zip Code 53202 E-Mail Ad dress djaeckles@bci.usa .biz Phone Number (800) 222-1509 Fax Number ARCHITECT OR ENGINEER 'S INFORMATION : Name Josh Schoeneman -Woods Associates Street Address 229 E. Wisconsin Ave .. Suite 700 City Milwaukee State WI Zip Code 53202 E-M ail Address jschoenemann@.woods-assoc.net Phone Number (414} 291-0772 Fax Number (414) 291-0773 C l t4 .,tn., , -~· - OTHER CONTACTS (Please specify type of contact, i.e. project manager, potential buyer, local contact, etc.) Name _________ _,_,N=m~A~p2p=lic=a=b=le'-----------------~--- Street Address------------------City __________ _ State _____ Zip Code _____ _ Phone Number __________ _ E-Mail Address------------- Fax Number -------------- PRESENT USE OF PROPERTY Vacant -~=='-'-=------------------------- PROPOSEDUSEOFPROPERTY =Ba=n~k,__ ____________________ _ VARIANCE(S) REQUESTED AND REASON(S) _N_on_e ________________ _ #OF PARKING SPACES REQUIRED ~15==----#OF PARKING SPACES PROVIDED 35 =--- MUL Tl-FAMILY RESIDENTIAL PARKLAND DEDICATION Total Acreage ____ _ #of Multi-Family Dwelling Units Floodplain Acreage __ _ _ __ x $452 = $ _______ _ Housing Units ____ _ ___ # of acres in floodplain # of 1 Bedroom Units # of acres in detention --- # of 2 Bedroom Units ___ # of acres in greenways --- # of 3 Bedroom Units __ date dedication approved by Parks --- Board # of 4 Bedroom Units COMMERCIAL --- FOR 2 BEDROOM UNITS ONLY Total Acreage .:::.3:..!..7=2=6 _____ _ ___ # Bedrooms = 132 sq. ft . Building Square Feet -=-37.:._1=2=----- ---#Bedrooms < 132 sq . ft. Floodplain Acreage .::::..O ____ _ NOTE: Parkland Dedication fee is due prior to the issuance of a Building Permit. Theap hereto nt has prepared this application and certifies that the facts stated herein and exhibits attached true and correct. · ('\ I ' Date SUPPLEMENTAL DEVELOPMENT PERMIT INFORMATION Application is hereby made for the following development specific site/waterway alterations : None ACKNOWLEDGMENTS: I, Veronica J.B . Morgan , design engineer/owner, hereby acknowledge or affirm that: The information and conclus ions contained in the above plans and supporting documents comply with the current re irements of the City of College Station , Texas City Code , Chapter 13 and its associated Drainage Policy and Design Sa dards . As a condition of approval of this permit applicat ion , I agree to construct the improvements proposed in this a 1 ica · rdi to these documents and the requirements of Chapter 13 of the College Station City Code . Engineer Date C. I, NIA , certify that the alterations or development covered by this perm it shall not diminish the flood-carry ing capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent with requirements of the City of College Station City Code, Chapter 13 concerning encroachments of floodways and of floodway fringes . Engineer Date D. I, N/A , do certify that the proposed alterations do not raise the level of the 100 year flood above elevation established in the latest Federal Insurance Administration Flood Hazard Study . Engineer Date Conditions or comments as part of approval :--------------------------- Jn accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that 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 . Jennifer Prochazka City of College Station Planning & Development P.O. Box 9960 College Station, TX 77842 MITCHELL M M MORGAN Re: Staff Review Comments for Brenham National Bank (SP) Dear Jennifer, Please ~ attached with this letter the following: • "pne (11) revised set of plan-5 to be returned to us and 6 for your records • I One (1) Landscape Plan • /One (1) Irrigation Plan • /ywo (2) copies of site plan • J Easement Dedication Sheet • Brenham Bank Corporate Resolution • Brenham Bank General Warranty Deed Below are the answers to the staff review comments dated January 20, 2006 . PLANNING: Comment: The "wetland fringe mix" is not permitted. Answer : The wetland fringe mix has been replaced with turf seed. February 1, 2006 Comment: FYI: the main drive aisles to this site are required to be fire lane, but have never been striped or signed . City staff is currently working with Code Enforcement to get this completed. They must either be striped or signed as fire lane prior to Certificate of Occupancy for this development Answer : Comment: Answer: Comment: Answer : Acknowledged . As the landscape plan is currently proposed, I do not feel that there is any vegetation that is "softening" the look of the pond (in lieu of screening). There is no vegetation planned within the pond as stated in the response to staff comments . Trees and trunks have now been added around the pond . Please submit blanket easement information. Please see attached . u have any questions or comments, please feel free to contact me at 260-6963 . Thank you . erely, vero~~~r Managini~~.rt~;gan~ P. Cc: File David Jaeckles Josh Schoenemann 511 UNIVERS ITY DR IVE EAST, SUI TE 204 • COLLEGE STATION, TX 77840 • T 979.260 .6963 • F 979.260.3564 CIVIL ENGINEERING • HYDRAULICS • HYDROLOGY • UTILITIES • STREETS • SITE PlANS • SUBDIVISIONS info@mitchellandmorgan .com • www.m1tchellandmorgan.com BRENHAM BAN K DRAINAGE ANALYSIS N o vember 2005 Prepared f or LLEGE TATI rhr hrarr (Jfihe Research Valley By MITCHELL M M MORGAN ENGINEERS & CONSTRUCTORS 511 UNIVER SITY DR IVE, SUI TE 204 COLLE GE STATION , TX 77840 OFFI CE (979) 260-6963 FA X(979)260-3564 CERTIFICATION "I hereby certify that I am familiar with the adopted ordinances, regulations, standards, and policies of the City of College Station governing development, that these plans have been prepared under my supervision, and that this drainage plan complies with governing ordinances and regulations to the best of my knowledge ." "The site of Brenham Bank, Lot 2A, Block 1 of the Libe rty Subdivision does not lie within the e ablished area of the special flood hazard as established by the current flood insurance s dy or flood insuran ce rate map panel number 144C, dated July 2, 1992 ." 6 ~,,, \ \//Yb_ 1) /";~~*.~ F: .. '..~~~~''r, :: .0 . ··. it ,, :".-' "..*~ ~. . . ............. .,_ -~--+-\t---tt---t-'r'------. · .~ ;; .. ~ ...... B.MORGAN ~ 0 an P.E., C.F .M. "-·« ' .~~-~: .. : ......... Tcr"~ Registered P fes · na Engineer 77~89 <:) /!fj J State of Texas No . 77689 ., ·. :· ~.-~G 1srt~~::..._&~ 11 ·~ _;·1aN·;.:_~ ~;:.-=-"\"''''''"~ Introduction BRENHAM BANK DRAINAGE ANALYSIS The purpose of this drainage report is to present an analysis of the necessary drainage infrastructure for the proposed Brenham Bank. This development will be located in College Station, at the southwest corner of the intersection of Southwest Parkway and the State Highway 6 East Bypass . The drainage report provides analysis for the infrastructure required to facilitate attenuation and removal of onsite flow . This report includes analysis for currently proposed development of the 4 .58 acre Lot 2A as well as the future development to the west of Brenham Bank, contained in postdevelopment drainage areas DA-P1 through DA-P6, shown on Exhibit B. Per the City of College Station Drainage Policy and Design Standards (DPDS) the parameters used for the design and analysis of pre-v. post- development conditions include adherence to the stated zero peak flow rate increase due to development set forth in the guidelines . General location and Description Brenham Bank will be located in College Station, Texas, at the SH6 and Southwest Parkway intersection. The development is located on Lot 2A, Block 1 of the Liberty Subdivision, which is currently undeveloped with the exception of a small access road that runs around the property. Stormwater runoff from the site will be detained in an on-site detention pond . The project location is shown in Exhibit A 1, Project Location Map . Drainage Design Criteria All drainage design is in accordance with the City of College Station DPDS . As such : • Flow calculations are based on the Rational Method with a minimum time of concentration of 10 minutes . • Design rainstorm events consist of the 5-, 10-, 25-, 50-and 100-year frequency storm events in order to analyze the effectiveness of the detention facilities as well as capture conservative peak flow values. All detention pond routing can be found in Exhibit C4 . • Flow calculations are based on the rational method using the guidelines provided in the DPDS, and can be found in Exhibit C1. The analysis confluence for this report is identified as the proposed junction box to be located on Southwest Parkway and tying into the existing 24" storm sewer approximately 60 ft to the west of the SH6 frontage road. Achievement of design objectives will be based on the effects of the proposed storm drainage system on this junction box . Primary Drainage Basin Description The project site is located within the Wolf Pen Creek Drainage Basin . As demonstrated in Exhibit A2, no portion of the project lies within the regulatory 100-year floodplain per the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) panel 144C, with an effective date of July 2, 1992 . The site drainage currently flows across the property in a northeasterly direction and is collected by an existing grate inlet at the corner of SH 6 and Southwest Parkway . 1:::1 Mitchell & Morgan, LLP Stormwater Runoff Analysis General Information Drainage characteristics for this analysis were selected from the DPDS guidelines . Drainage areas were delineated from the on-the-ground topographic survey data . This information can be seen in Exhibit 8, the Drainage Area Map . Predevelopment Drainage Analysis Per Exhibit 8, Pre-and Postdevelopment Drainage Area Map, all of Lot 2A d rains toward the aforementioned inlet at the SH6/Southwest Parkway intersection . Flow entering this inlet drains north through an existing storm sewer system, ultimately draining into Wolf Pen Creek . Runoff calculations were performed using the Rational Method. Approximately 5% of the property is currently impervious cover, with the remainder being wooded and grassy area. Peak runoff values for the predevelopment drainage basin are provided in Exhibit C1, Rational Formula Drainage Area Calculations . Sub-basin areas were based on topographic information provided and largely determined by the location of the bounding access streets . Postdevelopment Drainage Analysis As demonstrated in Exhibit 8, approximately 37% of the lot will remain undeveloped with construction of Brenham Bank as well as a future project (DA-P1) west of the bank to be completed at a later date. For the purposes of this study, it was assumed that the future project located in DA-P1 would have approximately 90% impervious cover . Drainage analysis for the site will assume ultimate development, requiring no rehabilitation to the proposed drainage infrastructure with the next development on the property. The ultimate development of the basin has approximately 63% impervious cover because of the amount of space occupied by the detention pond as well as the fact that a significant portion of the drainage area is within the TxDOT ROW . The postdevelopment drainage areas have been mod ified to reflect the drainage patterns resulting from the proposed grading and storm sewer improvements on the site; however, the total drainage basin area is the same for both the pre-and postdevelopment conditions . Proposed grading of the site and detention pond is provided as Exhibit E. Postdevelopment drainage patterns will remain similar to those of predevelopment conditions with a majority of the site drain ing toward the exist ing grate inlet. Flow from Brenham Bank will be d irected in the parking lot to a series of grate inlets, and into the proposed detention pond through a series of storm sewer pipes. The proposed storm sewer is shown in Exhibit D and capacity calcu lations have been provided in Exhibit C2 . The remainder of the flow will be directed to the pond by graded slopes . Water will be released from the detention pond through a fifteen inch (15") pipe to the existing storm sewer system at the proposed junction box in the Southwest Parkway ROW . D raina ge Fa cility Design Rational and Storage Indication Curve Modeling As previously mentioned, design flows were calculated using the rational method, as shown in Exhibit C1. The flows from rational analysis were routed through the detention pond using storage-indication curve routing techniques . Stage/Storage, Stage/Discharge, and Storage Indication Curves for the proposed detention pond may be found in Exhibit C3 . Storage-outflow routing was used to determine outflows from the pond to the proposed l::'.I Mitchell & Morgan, LLP 2 junction box for the 5-, 10-, 25-, 50-, and 100-year freq uency storm events, as shown in Exhibit C4 . Proposed Storm Drainage In frastructure A junction box w ill be constructed along the existing storm sewer line as indicated in Exhibit D in order to provide service from the proposed dete nt ion pond . Outflow from the detention pond is controlled by a proposed fifteen in ch (15") HDPE headwall and pipe. For the purpose of the calculations an overflow we ir was set at 277 . 50 ft; however, t he calculations also show that the peak water surface elevation for the 100-year event are below 2 77 .00 ft, al lowing for more than a foot (1 f t.) of freeboard to the top of berm, which has been set at 278 .00 ft. In the event that t he storm dra in syste m is clogged, site grading has been established such that flows from the po nd will overflow the detention pond berm and enter the sto rm sewer along So uthwest Parkway . In addition, the minimum finished floor on the building will be 285 .00 ft., appro ximately 2 ft. above the Southwest Parkwa y elevations, allowing adequate overland relief . D r ainage Analysis Results As demonst rated in Exh ibits C 1 to C4, there are no peak flow rate increases at the study confluence . In fact , there are significant decreases due to the large si ze of the detention pond, even though we are consider i ng full development of the property in the analysi s. The detention pond has been sign ificantly oversized i n order to provide enough fill material to place the site and bui ld ing at a des irable elevation. Peak flow rates at the junction bo x were re d uced in all storm frequenc ies studied, as shown in Table 1 below . The design of the storm sewer system resulted in a 100-year peak flow rate of 10.8 cfs at the Study Point outfall and a 100-year peak wate r surface in the pond of 276 .90 feet, which prov ides more than a foot of freeboard for the berm of the detention pond . Table 1. Pea k Disc h a r es at Pr opose d Ju n ction Box Development 5-Year Peak 10-Year Peak 25-Year Peak 50-Year Peak 100-Year Peak Flow Conditions Flow (cfs) Flow (cfs) Flow (cfs) Flow (cfs) (cfs) Pred eveloi;imen t 16 .3 18.2 20 .8 23 .6 Postdevel opment 2 6 .3 29 .5 33.7 38 .1 42 .8 Peak Flow Increase 10 .0 11 .3 1 ~9 14.5 16.3 Post-Detention 9 .1 9 .5 10.0 10 .3 10 .8 Peak Fl ow Reduction 7.2 8.7 10 .8 13.3 15.7 Conclusion s The development of the Brenham Bank wi ll cause a substantia l increase in pea k stormwater runoff d ue to the add ition of a significant amount of impervious cover to the site. The analysis of the proposed st o rm drainage infrastructure yields a picture of the drainage conditio ns during a substantial rainfall event ensures that no significant flood ing w ill occur on the proposed site . Review of the stormwater analysis indicates that the drainage design presented in this report will provide ample conveyance and detention to meet th e drainage obj ective of the City of College Station DPDS . l::'.I M itchell & Morg an, LLP 3 <( ~ w 0 0:: _J <( <( c LL w w z I-c (!) 0:: <( z <( z <( <( _J _J w (.) <( ::c: z _J (/) w ~ _J _J I- <( <( (/) > w <( 0:: (!) I-<( <( > I-wz 0:: 0 0:: 0:: <( 0 >w c I-(!) (!) a.. I-0 _J NO. AC . 0.45 0.65 0.95 ft . DA-E1 4.46 4 .24 0 .00 0 .22 2 .11 300.0 -DA-P 1 1.23 0 .11 0 .00 1.12 1 .11 100 .0 ,_ DA-P2 1.78 1.28 0 .00 0.50 1.05 220 .0 , •. -·--DA-P3 0 .12 0 .00 0 .00 0 .12 0.12 0 .0 ,_ --,_ DA-P4 0.41 0 .00 0 .00 0.41 0 .39 0 .0 ·-. -1~ DA-PS 0 .53 0.24 0 .00 0 .28 0 .38 0 .0 -DA -P6 0 .39 0 .00 0 .00 0.39 0 .37 0 .0 EXHIBIT C1 Rational Fo r mula Drainage Area Ca l cu l ation s BRENHAM BANK ~ 0 ~ ~ _J LL 0 0 c _J _J z LL LL >- <( 0:: ::c: 0:: I-0 _J w I-w C3 I-0 0:: _J I-(!) I-_J 0 I- w _J I-z I-_J _J ..!::? w > <( ::::> w ::::> <( w ns (/) N Q LL (!) _J (!) LL > (.) ::::> ~ 0 ~ ft . ft . ft. fUs m i n min In/H r cfs In/Hr 2 .0 50 .0 0 .5 0 .6 9.1 10 .0 6 .33 13.4 7.7 ---2 .0 450 .0 4 .0 1.6 5.7 10 .0 6 .33 7 .0 7 .7 1.0 100.0 7.0 0.7 8.0 10.0 6.33 6 .6 7 .7 0 .0 50 .0 2 .0 4 .0 0 .2 10 .0 6 .33 0 .7 7 .7 ·-0 .0 50 .0 2 .0 4 .0 0.2 10 .0 6 .33 2.4 7 .7 ·~ ,_ ,_ 0 .0 50 .0 2 .0 4 .0 0 .2 10.0 6 .33 2.4 7 .7 0 .0 50 .0 2 .0 4 .0 0 .2 10 .0 6 .33 2.4 7 .7 0 "' "' 0 ..... "' N 0 ..... 0 ~ 0 -cfs In/Hr cfs In/H r cfs 16.3 8 .6 18 .2 9 .9 20.8 8 .6 8.6 9 .6 9 .9 11 .0 8 .1 8.6 9.1 9 .9 10.4 0 .9 8.6 1.0 9 .9 1.1 3.0 8.6 3.3 9 .9 3.8 - 2 .9 8.6 3 .3 9 .9 3 .7 2 .9 8 .6 3.2 9 .9 3.7 0 0 "' ~ 0 In/Hr cfs 11 .1 23 .6 ·- 11 .1 12.4 11 .1 11 .7 - 11 .1 1.3 11 .1 4 .3 11 .1 4 .2 11 .1 4 .2 0 0 0 0 ..... !:: 0 In/Hr cfs 12.5 26 .5 ·-12 .5 13 .9 12.5 f"-131. 12 .5 1.5 12 .5 4 .8 - 12 .5 4 .7 12 .5 4 .7 11/3/2005 0533-D ra EXHIBITC1 0 z E-< ~ ,_:j ~ # DA-E1 DA-P4 DA-PS DA-P6 E-< ::3 ~ 0 E-< # Grate POND DA-P4 DA-PS < u ~ E-< 0 E-< Ac. 2.1 1.1 0.8 0.4 CJ E-< min 10.0 10.5 10.1 10.0 a i.. 0 .... rJl c 0.() ·;;; ~ ~ yr 100 100 100 100 "O ~ ~ 0 .... -~~ . ..., c "O 0.() ~ ·-c "' ~~ cfs 26.5 14.0 9.4 4.7 EXHIBIT C2 Pipe Capacity Calculations BRENHAM BANK -1: ~ 0 "O ~ ~ .... c "' 0.() ::s ·-. ..., "' "O ~ <~ cfs 26.5 17.5 11.7 5.8 "' ~ c. ~ .... 0 0 z # 1 ~ c. ~ i.. ~ p., ~ 0 ~ cfs 26.5 17.5 11.7 5.8 c -1: 0 -1: ·-~ ti c. ·-0 i.. -~ 00 % 0.09 0.71 0.73 0.48 ~ c. 0 Ci5 ~ c. ~ O/o 0.34 0.75 0.75 0.75 ~ N .... rJl " 36 21 18 15 .j ~ > fps 7.2 7.4 6.7 5.9 -1: c ·;::; ~ c. ~ u cfs 50.7 17.9 11.9 7.3 = E-< C,!) z ~ ...;i 37 165 43 ~ a ~ Q:j ;> ~ i.. E-< min 0.00 0.08 0.41 0.12 "O c ~ @) CJ E-< min 10.00 10.61 10.53 10.12 11/3/2005 0533-Dra Exhibit C2 EXHIBIT C3 Stage/Storage -Stage/Discharge -Storage Indication Curves BRENHAM BANK Elevation Area Area (ft .) (sf.) (acres) 272.0 0 0 .000 273.0 863 0 .020 274 .0 5608 0 .129 275 .0 7538 0 .173 276 .0 9679 0 .222 277 .0 11959 0 .275 278 .0 14516 0.333 279 .0 15000 0.344 280 .0 15000 0.344 BRENHAM BANK Storage Indication Curve 3000 -...--~-----~---~ 1 ::1 ~ ~ 1000 .~::1::::::.:::1::::::::::1:::::::::: N : : : : 500 -·---.... _; _ ----.. ----~ ---------_; _ ------. --~----------- ~ : : : : 0 141 : : : : 0 50 100 150 200 250 Discharge (cfs) Inc . Volm . Volume Outlet 1 Outlet 2 Total (ac .-ft.) (ac .-ft .) Invert Elev . (ft .) 272 277 .5 Flow Orifice Dia . (in .) or Weir Length (ft.} 15 20 Outfall Orifice (cfs) Orifice (cfs) (cfs) 0.000 0.000 0.007 0.007 0.066 0.073 0 .150 0 .223 0.197 0.420 0.248 0.668 0.303 0.972 0 .339 1.311 0.344 1.655 BRENHAM BANK Stage-Storage Curve 1.400 -.-------~--~-----.. 1.200 ~ 1.000 0 ~ 0 .800 Cl> •••••••••• L •••••••••• L ••••••••• J ••••••••••••••••••• . . . . . . . . . . . ····••··••r••••••••••••••••••••••••·•••·••• •········ . . . . . . . . . ' ' ' ' -----------------------------------------------------' ' ' ' ' ' ' ' ' ' ' ' . . . ~ 0 .600 ------·--·:---·-···-·:·-------·-:---------:-·----·-·- 0 . . U5 0.400 -·---·--··t··--······t··-----·-: ---·--··-1···----··- 0 .200 ·----------~---------~---· ----!---------~---------- 0 .000 +---..:..,__..~~_,._ __ ,__ _ ___.__----! 270 272 274 276 278 280 Elevation (msl) 0 .00 4 .87 6.89 8.44 9 .75 10 .90 11 .94 12 .90 13 .79 0 .00 0.00 0.00 4 .87 0.00 6.89 0 .00 8.44 0.00 9.75 0 .00 10 .90 21.21 33.15 110 .23 123 .12 237 .17 250 .96 BRENHAM BANK Stage-Discharge Curve 300 ~-------~-------. 250 ~ ••••••••• ••····••••••'·•••••····-L·-···••••• . . . . . . . . . . . . ~ 200 . . . -·········1···········.-······--··r·····--------------- • . . Cl> . . . . . . E' 150 -·----·····---··-·-··-•····················-· -·------- CV : : : . . . .r=. : ' : ~ 100 ·· --------:-----------:·---------·c------· · ------------- Ci : : : 50 ----------;---------·-:--···----------··------------- o -l----4il....-~~~~t:::~~~~~· ~c.._+----1 270 .0 272 .0 274 .0 276 .0 278 .0 280 .0 Elevation (msl) 11 /3/2005 053 3-Dra Exhibit C3 -.i::; a. !'!! Cl e .... a:: "' M Cl. Cl. Cl. "C < < < < >. ::c c c c c Qp 10.7 8 .6 8.1 0.9 Tc 11.0 10.0 10.0 10.0 Min inc 1.0 1.0 1.0 1 .0 Time cfs cfs I cfs cfs 0.0 0 .0 0.0 0 .0 0 .0 1.0 1.0 0.9 0.8 0 .1 2.0 1.9 1.7 1.6 0 .2 3.0 2 .9 2.6 2 .4 0.3 4 .0 3 .9 3.4 3.2 0.4 5.0 4.9 4 .3 4 .0 0 .4 6 .0 5.8 5.1 4 .8 0 .5 7.0 6 .8 6 .0 5.7 0.6 8 .0 7 .8 6 .9 6.5 0 .7 9.0 8 .8 7.7 7 .3 0.8 10 .0 9 .7 8.6 8 .1 0.9 11.0 10 .7 8.1 7 .7 0.9 12.0 10.2 7 .7 7.3 0.8 13.0 9.7 7 .3 6 .9 0.8 14.0 9.2 6 .9 6 .5 0 .7 15.0 8.8 6 .4 6.1 0.7 16 .0 8.3 6 .0 5 .7 0 .6 17 .0 7.8 5.6 5.3 0 .6 18 .0 7 .3 5 .1 4.8 0 .5 19.0 6.8 4 .7 4 .4 0 .5 20 .0 6 .3 4 .3 4 .0 0.4 21.0 5.8 3.9 3.6 0.4 22.0 5 .4 3.4 3 .2 0.4 23 .0 4 .9 3.0 2.8 0.3 24 .0 4 .4 2 .6 2.4 0.3 25 .0 3.9 2 .1 2.0 0.2 26 .0 3.4 1.7 1.6 0 .2 27 .0 2 .9 1.3 1.2 0.1 28 .0 2 .4 0 .9 0 .8 0.1 29.0 1.9 0.4 0.4 0 .0 30 .0 1.5 0 .0 0 .0 0.0 31.0 1.0 0.0 0.0 0 .0 32.0 0.5 0 .0 0 .0 0 .0 33.0 0 .0 0 .0 0 .0 0 .0 34 .0 0 .0 0 .0 0 .0 0 .0 35.0 0 .0 0 .0 0 .0 0.0 36 .0 0 .0 0 .0 0 .0 0 .0 37.0 0 .0 0 .0 0 .0 0 .0 60 .0 0 .0 0 .0 0 .0 0 .0 61.0 0.0 0 .0 0.0 0.0 62 .0 0 .0 0 .0 0 .0 0 .0 63.0 0.0 0 .0 0.0 0.0 64 .0 0 .0 0 .0 0 .0 0 .0 PEAK FLOWS 10.7 8.6 8.1 0.9 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c c a w t. c z :E iii + q + :ii: c !? + c 0 ~ ~ u = cfs cfs cfs cfs 0.0 2.7 0 .0 0 .0 2.7 8.2 0.9 2.7 5 .5 13.6 3.0 9 .1 8.2 19.1 6.8 16 .6 10.9 24 .5 15.6 25.8 13.6 30 .0 29.4 40 .2 16.4 35 .5 47 .8 59 .4 19 .1 40 .9 70 .7 83.2 21 .8 46.4 97 .8 111.6 24 .5 51 .8 130 .0 144 .2 27 .3 54 .6 167 .0 181 .8 27 .4 53 .4 206 .3 221.6 26 .0 50 .6 243.8 259.7 24 .6 47.9 278 .1 294.5 23 .3 45 .2 309 .3 326.0 21 .9 42 .5 337 .4 354.4 20.5 39 .7 362.5 379 .8 19 .2 37 .0 384 .7 402.2 17 .8 34 .3 404 .0 421 .7 16 .5 31 .6 420 .5 438 .3 15.1 28.8 434 .0 452 .0 13.7 26 .1 444.8 462 .9 12 .4 23.4 452 .8 470.9 11.0 20.6 457.9 476 .1 9 .6 17.9 460.4 478 .6 8 .3 15.2 460 .1 478 .3 6 .9 12 .5 457.1 475.3 5.6 9.7 451 .4 469.6 4 .2 7.0 443 .1 461 .2 2 .8 4 .3 432.2 450.1 1.5 2.4 418.6 436 .5 1.0 1.5 403 .4 421.1 0 .5 0 .5 387.3 404 .8 0.0 0 .0 370.4 387.8 0 .0 0 .0 353 .2 370 .4 0 .0 0 .0 336 .1 353 .2 0 .0 0 .0 319 .2 336.1 0.0 0 .0 302 .5 319 .2 0 .0 0 .0 1.3 3 .9 0 .0 0.0 0.4 1.3 0 .0 0 .0 0.1 0.4 0 .0 0.0 0.0 0.1 0.0 0.0 0 .0 0 .0 27.4 5 c .2 -.; fil ~ > Cl> II) 0 3: jjj 0 ...J 0 Cl. u. s "C 0 I-c 6 0 g: 5 Cl. cfs ft cfs 0.0 272 .0( 0 .0 0.9 272 .19 0.9 3 .1 272.6' 3.1 4 .9 273.02 4 .! 5 .1 273 .1< 5. 5.4 273.26 5.• 5 .8 273.46 5 .f 6 .3 273 .70 6 .' 6 .9 273 .99 6.9 7.1 274 .14 7.1 7.4 274.31 7.4 7.7 274 .49 7.7 7 .9 274.67 7.9 8.2 274 .83 8.2 8.4 274 .97 8.4 8.5 275 .08 8.5 8.7 275.1€ 8.7 8.8 275 .24 8.8 8.8 275.31 8 .8 8.9 275.37 8 .9 9 .0 275.42 9 .0 9.0 275 .45 9.0 9 .1 275.4E 9.1 9 .1 275.50 9.1 9.1 275 .51 9.1 9 .1 275.51 9 .1 9 .1 275 .5( 9.1 9.1 275.48 9.1 9 .0 275.4~ 9.0 9 .0 275 .41 9 .0 8 .9 275 .3E 8.9 8.8 275 .31 8.8 8 .8 275 .2~ 8.8 8.7 275 .19 8.7 8.6 275.12 8 .6 8.5 275 .07 8.5 8 .5 275 .01 8.5 8.3 274 .94 8.3 1.3 272 .27 1.3 0.4 272 .09 0.4 0 .1 272 .02 0.1 0.0 272 .01 0 .0 0 .0 272 .0C 0 .0 Total (Detained 9.1 275.5111 9.1 (!) ...J :r!:: w c( I- I-!a < g~ c 16 .3 10 .0 cfs cfs 0 .0 0 .0 1.6 1.6 3.3 3 .3 4 .9 4.9 6 .5 6 .5 8.1 8.1 9.8 9 .8 11.4 11.4 13.0 13 .0 14 .6 14.6 16.3 16.3 15 .4 15.4 14.6 14.6 13.8 13 .8 13 .0 13 .0 12.2 12 .2 11 .4 11.4 10.6 10.6 9.8 9.8 8.9 8 .9 8 .1 8.1 7.3 7.3 6.5 6 .5 5.7 5.7 4 .9 4 .9 4 .1 4 .1 3.3 3 .3 2.4 2 .4 1.6 1.6 0.8 0.8 0 .0 0 .0 0.0 0.0 0 .0 0.0 0.0 0.0 0.0 0 .0 0.0 0 .0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0.0 0 .0 0 .0 Total (Predeveloped 16.3 11/3/200 5 0533 -Dra Exhibit C4 'II: .r: c. f Cl e "" a: N M D.. D.. D.. ,, ci: ci: ci: ci: >-:c 0 0 0 0 Qo 12.0 9.6 9 .1 1.0 Tc 11 .0 10 .0 10 .0 10 .0 Min inc 1.0 1.0 1.0 1.0 Time cfs cfs cfs cfs I 0 .0 0 .0 0.0 0 .0 0 .0 1.0 1.1 1.0 0.9 0.1 2 .0 2 .2 1.9 1.8 0 .2 3.0 3.3 2.9 2 .7 0.3 4 .0 4.4 3.8 3.6 0 .4 5.0 5.5 4 .8 4 .5 0 .5 6 .0 6.6 5 .8 5.4 0 .6 7 .0 7.7 6 .7 6.3 0.7 8 .0 8.7 7 .7 7.3 0 .8 9.0 9.8 8 .7 8 .2 0 .9 10 .0 10 .9 9 .6 9 .1 1.0 11.0 12 .0 9 .1 8.6 1.0 12 .0 11 .5 8 .7 8 .2 0.9 13.0 10 .9 8 .2 7.7 0.9 14 .0 10.4 7 .7 7 .3 0 .8 15.0 9.8 7 .2 6 .8 0 .8 16 .0 9 .3 6 .7 6 .3 0.7 17 .0 8 .7 6 .2 5.9 0.7 18.0 8.2 5.8 5.4 0.6 19 .0 7.7 5.3 5.0 0.6 20 .0 7.1 4 .8 4.5 0 .5 21 .0 6 .6 4 .3 4.1 0.5 22.0 6 .0 3.8 3.6 0.4 23 .0 5.5 3.4 3.2 0.4 24 .0 4.9 2.9 2 .7 0.3 25 .0 4.4 2.4 2.3 0.3 26 .0 3.8 1.9 1.8 0 .2 27 .0 3.3 1.4 1.4 0.2 28.0 2 .7 1.0 0 .9 0 .1 29.0 2 .2 0 .5 0.5 0.1 30 .0 1.6 0 .0 0.0 0.0 31 .0 1.1 0.0 0.0 0 .0 32.0 0.5 0 .0 0 .0 0 .0 33.0 0 .0 0 .0 0.0 0.0 34.0 0.0 0 .0 0 .0 0 .0 35 .0 0 .0 0.0 0.0 0.0 36.0 0 .0 0 .0 0 .0 0 .0 37.0 0.0 0.0 0.0 0 .0 60.0 0 .0 0 .0 0 .0 0 .0 61 .0 0 .0 0.0 0.0 0.0 62 .0 0 .0 0.0 0.0 0 .0 63 .0 0 .0 0.0 0 .0 0.0 64 .0 0 .0 0 .0 0.0 0 .0 PEAK FLOWS 12 .0 9.6 9.1 1.0 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c 0 a w t. z c in + a :e ~ + == c ,, + c 0 ~ ~ u c cfs cfs I cfs cfs 0 .0 3.1 0 .0 0 .0 3.1 9 .2 1.0 3.1 6 .1 15.3 3.3 10 .2 9 .2 21.4 8 .7 18.6 12 .2 27 .6 19 .7 30.1 15 .3 33 .7 36.2 47 .3 18.4 39 .8 57 .9 69 .9 21.4 45 .9 84 .5 97 .7 24 .5 52 .0 116.4 130 .4 27.6 58 .2 153.9 168 .4 30 .6 6 1.3 196.8 212.0 30 .7 59 .9 242.3 258.2 29 .2 56 .9 285 .8 302 .3 27 .7 53 .8 325 .7 342 .7 26 .1 50 .7 362.2 379 .5 24 .6 47 .7 395.3 412.9 23 .1 44 .6 425 .1 443 .0 21 .5 41.5 451.5 469.7 20 .0 38 .5 474 .7 493 .1 18.5 35 .4 494.7 513 .2 16 .9 32 .4 511 .5 530 .1 15 .4 29 .3 525.0 543.8 13 .9 26.2 535.4 554 .3 12 .4 23.2 542 .7 561 .7 10 .8 20 .1 546 .9 565.9 9.3 17 .1 548 .0 567.0 7 .8 14 .0 546 .0 565.0 6 .2 10 .9 541 .1 560.0 4 .7 7.9 533 .1 552 .0 3.2 4 .8 522.2 541 .0 1.6 2.7 508 .4 527 .0 1.1 1.6 492 .6 511.1 0 .5 0.5 475 .9 494.2 0.0 0.0 458.2 476.4 0.0 0 .0 440.2 458 .2 0.0 0.0 422 .3 440.2 0.0 0.0 404 .6 422 .3 0.0 0 .0 387.1 404 .6 0 .0 0 .0 43 .1 54 .5 0 .0 0 .0 32 .2 43 .1 0.0 0 .0 21 .7 32.2 0.0 0.0 11 .7 21.7 0 .0 0 .0 3 .8 11 .7 30 .7 10 c :8 "' fil ~ > Cl> en o ~ iii 0 _, 0 ,, D.. LL s 0 I-c 6 0 a::::::> D.. D.. 0 I cfs ft cfs 0.0 272 .0 C 0.0 1.0 272 .21 1.0 3.4 272.7( 3.4 5 .0 273 .04 5.0 5 .2 273 . H 5.2 5.5 273 .33 5.5 6 .0 273 .5! 6 .C 6 .6 273.85 6 .6 7 .0 274 .0! 7 .0 7 .3 274.25 7.3 7 .6 274.4' 7.6 7.9 274.66 H 8 .2 274.8€ 8.2 8.5 275.03 8 .' 8 .7 275 .1€ 8. 8.8 275 .28 8.8 8 .9 275 .3E 8.9 9.1 275 .48 9.1 9.2 275.5E 9.2 9.3 275 .63 9.3 9 .3 275 .6S 9.3 9.4 275 .73 9.4 9.4 275 .77 9.4 9.5 275 .80 9.5 9.5 275 .81 9 .5 9 .5 275 .81 9. 9 .5 275 .81 9 . 9.5 275 .79 9. 9.4 275 .7! 9 . 9.4 275.72 9 9.3 275 .6E 9 9.3 275 .62 9.3 9 .2 275 .56 9 .2 9.1 275 .50 9 .1 9 .0 275.44 9 . 8.9 275 .37 8 . 8 .9 275.31 8 . 8.8 275.25 8.E 5.7 273.41 5.1 5.5 273 .29 5! 5 .2 273 .H 5 .2 5.0 273 .07 5.C 3 .9 272 .81 3 . Total {Detained 9.5 275.81 9.5 C) _, :!!:: w ct I- I-!a ci: e~ 0 18 .2 10 .0 cfs cfs 0 .0 0 .0 1.8 1.8 3.6 3 .6 5.5 5.5 7 .3 7 .3 9 .1 9.1 10 .9 10.9 12 .8 12 .8 14 .6 14 .6 16.4 16.4 18 .2 18 .2 17 .3 17 .3 16.4 16.4 15 .5 15 .5 14 .6 14.6 13 .7 13 .7 12.8 12 .8 11 .9 11 .9 10 .9 10 .9 10 .0 10 .0 9 .1 9.1 8.2 8.2 7.3 7 .3 6 .4 6 .4 5 .5 5.5 4 .6 4 .6 3.6 3.6 2.7 2.7 1.8 1.8 0.9 0 .9 0.0 0 .0 0.0 0 .0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0 .0 0.0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0.0 0 .0 Total (Predevelooed 18.2 11 /3/200 5 0533-Dra Exhibit C4 -r. a. E en e .. a: N M ll.. ll.. ll.. "Cl < < < < :>. :r c c c c Qp 13.7 11 .0 10.4 1.1 Tc 11 .0 10.0 10 .0 10 .0 Min inc 1 .0 1.0 1.0 1.0 Time cfs cfs cfs cfs 0 .0 0 .0 0 .0 0 .0 0 .0 1.0 1.2 1.1 1.0 0 .1 2.0 2 .5 2 .2 2 .1 0.2 3.0 3.7 3.3 3 .1 0.3 4 .0 5.0 4.4 4 .1 0.5 5.0 6 .2 5.5 5.2 0.6 6 .0 7 .5 6 .6 6 .2 0.7 7.0 8 .7 7.7 7.2 0.8 8 .0 10 .0 8 .8 8 .3 0 .9 9.0 11 .2 9.9 9.3 1.0 10 .0 12 .5 11.0 10 .4 1.1 11.0 13 .7 10.4 9.8 1.1 12 .0 13 .1 9 .9 9 .3 1.0 13.0 12 .5 9 .3 8.8 1.0 14 .0 11 .9 8 .8 8 .3 0.9 15 .0 11.2 8.2 7.8 0.9 16 .0 10 .6 7 .7 7 .2 0.8 17.0 10 .0 7.1 6.7 0.7 18 .0 9.4 6 .6 6 .2 0 .7 19 .0 8.7 6 .0 5.7 0.6 20.0 8.1 5.5 5.2 0.6 21 .0 7 .5 4 .9 4.7 0 .5 22.0 6.9 4.4 4 .1 0.5 23.0 6.2 3.8 3.6 0.4 24.0 5.6 3 .3 3.1 0 .3 25.0 5.0 2 .7 2 .6 0.3 26 .0 4 .4 2 .2 2 .1 0 .2 27.0 3.7 1.6 1.6 0.2 28 .0 3 .1 1.1 1.0 0 .1 29 .0 2.5 0.5 0.5 0.1 30 .0 1.9 0 .0 0 .0 0.0 31 .0 1.2 0.0 0.0 0.0 32 .0 0 .6 0 .0 0.0 0 .0 33 .0 0.0 0 .0 0.0 0.0 34 .0 0 .0 0.0 0 .0 0 .0 35 .0 0 .0 0.0 0.0 0 .0 36 .0 0 .0 0 .0 0 .0 0 .0 37 .0 0.0 0.0 0.0 0 .0 60 .0 0 .0 0 .0 0 .0 0 .0 61 .0 0 .0 0.0 0.0 0 .0 62 .0 0 .0 0.0 0 .0 0 .0 63 .0 0.0 0.0 b.o 0 .0 64 .0 0 .0 0 .0 0 .0 0.0 PEAK FLOWS 13 .7 11.0 10.4 1.1 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c c a w t. c z ~ iii + a ~ .... :IE c + + c 0 i!i ~ (_) c cfs cfs cfs cfs 0 .0 3.5 0 .0 0 .0 3.5 10 .5 1.1 3 .5 7 .0 17.5 3.8 11 .6 10 .5 24 .5 11.2 21 .3 14 .0 31 .5 25 .1 35 .7 17 .5 38 .5 45 .1 56.6 21.0 45 .5 71 .0 83 .6 24 .5 52.5 102.6 116.4 28 .0 59.4 140 .7 155 .1 31 .5 66.4 185.1 200 .1 35.0 70.1 235 .8 251 .5 35.1 68.4 289.4 305 .9 33 .3 64 .9 340 .7 357.8 31 .6 61 .4 388 .1 405 .6 29 .8 57 .9 431 .6 449 .5 28 .1 54 .5 471 .2 489 .5 26.4 51 .0 507.0 525 .7 24.6 47 .5 539 .0 558 .0 22.9 44.0 567 .3 586 .5 21.1 40 .5 591 .8 611.3 19.4 37.0 612 .7 632 .3 17 .6 33 .5 630 .0 649.7 15 .9 30 .0 643.7 663.5 14 .1 26 .5 653 .8 673.7 12.4 23 .0 660.4 680 .3 10 .6 19 .5 663 .5 683.4 8.9 16 .0 663.1 683 .0 7 .1 12 .5 659.2 679.1 5.4 9 .0 651 .9 671 .7 3 .6 5.5 641 .1 660 .9 1.9 3.1 626 .9 646.6 1.2 1.9 610 .5 630 .0 0 .6 0 .6 592 .9 612.4 0.0 0.0 574 .3 593 .6 0 .0 0 .0 555 .2 574 .3 0 .0 0.0 536.3 555.2 0 .0 0 .0 517 .6 536 .3 0.0 0.0 499 .0 517.6 0.0 0 .0 122 .2 136.4 0.0 0.0 108.3 122 .2 0 .0 0 .0 94 .7 108.3 0.0 0.0 81 .7 94 .7 0.0 0 .0 69.2 81 .7 35.1 25 c ~ "' fil 5: > QI rn o 3: w 0 ..J 0 ll.. LL 5 "Cl o~ c 6 0 g: 5 ll.. cfs ft cfs 0 .0 272 .0( 0.0 1.2 272.24 1.2 3 .9 272 .8C 3.9 5.0 273.07 5.0 5.3 273.2:< 5.3 5.7 273.43 5.7 6 .3 273.7( 6 .3 6.9 274.02 6 .9 7 .2 274 .1~ 7 .2 7 .5 274.40 7.5 7 .9 274 .6: 7 .9 8.3 274.88 8.3 8 .6 275 .m 8.6 8.8 275 .25 8.8 9 .0 275.41 9 .0 9.2 275.55 9.2 9 .3 275 .6i 9.3 9.5 275.78 9.5 9 .6 275.81 9.6 9.7 275.97 9.7 9 .8 276 .0: 9 .8 9 .8 276 .08 9.8 9 .9 276 .1; 9 .9 9.9 276.15 9.9 9.9 276 .1i 9 .9 10.0 276 .18 10.0 9 .9 276 .1i 9.9 9 .9 276.16 9.9 9 .9 276 .1£ 9.9 9.9 276.11 9 .9 9 .8 276.0i 9 .8 9 .8 276 .03 9.8 9 .7 275.97 9 .7 9.6 275.91 9 .6 9 .5 275.84 9 .5 9.5 275 .77 9.5 9.4 275.7 9.4 9.3 275 .64 9.3 7 .1 274.11 7 .1 7.0 274 .0 4 7.0 6 .8 273 .95 6 .8 6 .5 273 .82 6 .5 6 .3 273 .68 6 .3 Total (Detained 10.0 276 .1811 10.0 (!) ..J :i!:: w <~ ~ !Q < e~ c 20.8 10.0 cfs cfs 0 .0 0 .0 2 .1 2.1 4 .2 4 .2 6 .3 6 .3 8 .3 8 .3 10.4 10.4 12 .5 12 .5 14 .6 14 .6 16 .7 16 .7 18.8 18 .8 20.8 20 .8 19.8 19 .8 18 .8 18 .8 17 .7 17 .7 16 .7 16 .7 15 .6 15.6 14 .6 14 .6 13 .5 13 .5 12 .5 12 .5 11 .5 11 .5 10.4 10.4 9.4 9.4 8 .3 8 .3 7.3 7.3 6 .3 6.3 5.2 5.2 4 .2 4 .2 3.1 3.1 2.1 2 .1 1.0 1.0 0.0 0.0 0.0 0 .0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0 .0 0 .0 0 .0 0.0 0 .0 0 .0 0 .0 0 .0 0.0 0.0 0 .0 0.0 0.0 0 .0 0 .0 Total (Predeveloped 20 .8 11 /3/2005 0533-Dra Exhibit C4 -.c c.. f Cl ~ "' ... N .... D. D. D. D. "O < < < < >. ::c 0 0 0 0 Qp 14.7 12.4 11.7 1.3 Tc 11 .0 10.0 10 .0 10 .0 Min inc 1.0 1.0 1 .0 1.0 Time cfs cfs cfs cfs I 0 .0 0.0 0 .0 0.0 0 .0 1.0 1.3 1.2 1.2 0 .1 2.0 2.7 2 .5 2 .3 0.3 3.0 4.0 3.7 3.5 0.4 4.0 5.4 5.0 4 .7 0 .5 5.0 6 .7 6 .2 5.9 0.6 6.0 8.0 7.4 7.0 0 .8 7 .0 9.4 8.7 8.2 0.9 8.0 10 .7 9.9 9.4 1.0 9 .0 12 .0 11 .2 10.5 1.2 10.0 13.4 12.4 11 .7 1.3 11 .0 14 .7 11.8 11.1 1.2 12.0 14.1 11 .2 10.5 1.2 13.0 13.4 10 .6 10 .0 1.1 14 .0 12.7 9.9 9.4 1.0 15.0 12.0 9 .3 8.8 1.0 16.0 11.4 8.7 8 .2 0 .9 17.0 10.7 8.1 7.6 0 .8 18.0 10.0 7.4 7.0 0 .8 19 .0 9.4 6 .8 6.4 0 .7 20 .0 8.7 6 .2 5 .9 0 .6 21.0 8.0 5.6 5.3 0 .6 22.0 7 .4 5 .0 4 .7 0.5 23 .0 6 .7 4 .3 4 .1 0 .5 24.0 6 .0 3 .7 3 .5 0.4 25 .0 5.4 3.1 2.9 0 .3 26.0 4 .7 2 .5 2.3 0 .3 27 .0 4 .0 1.9 1.8 0 .2 28.0 3.3 1.2 1.2 0 .1 29.0 2 .7 0.6 0.6 0 .1 30.0 2.0 0 .0 0.0 0.0 31.0 1.3 0 .0 0.0 0.0 32.0 0.7 0 .0 0.0 0.0 33.0 0.0 0 .0 0.0 0.0 34.0 0.0 0 .0 0 .0 0 .0 35 .0 0 .0 0 .0 0.0 0.0 36 .0 0 .0 0 .0 0 .0 0 .0 37 .0 0.0 0.0 0.0 0 .0 60.0 0.0 0 .0 0 .0 0.0 61 .0 0.0 0 .0 0 .0 0.0 62.0 0 .0 0 .0 0 .0 0 .0 63 .0 0.0 0 .0 0 .0 0.0 64.0 0 .0 0 .0 0 .0 0 .0 PEAK FLOWS 14.7 12 .4 11.7 1.3 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c 0 a w t. z c iii ... 2 :E + + ::Iii c "O + c 8 iii I/) c "' "' cfs cfs cfs cfs 0.0 3 .9 0.0 0 .0 3.9 11.6 1.3 3.9 7.8 19.4 4 .2 12 .9 11 .6 27.2 13 .5 23 .6 15.5 34.9 29.8 40.6 19.4 42.7 52 .9 64.7 23 .3 50.4 82.5 95 .6 27 .2 58 .2 118 .9 133 .o 31 .0 66 .0 162.4 177.1 34 .9 73 .7 213 .0 228 .4 38 .8 77 .7 270.5 286.7 38 .9 75 .8 331 .1 348 .1 36 .9 71 .9 389 .4 406 .9 35 .0 68 .0 443 .2 461 .3 33.1 64 .2 492.8 511 .3 31 .1 60 .3 538 .0 556 .9 29 .2 56.4 579 .0 598 .3 27.2 52 .5 615 .8 635.4 25 .3 48 .6 648 .5 668.3 23.4 44 .8 677.2 697 .2 21.4 40 .9 701.8 721 .9 19 .5 37 .0 722.4 742 .7 17 .5 33 .1 739 .0 759.4 15.6 29 .2 751 .6 772 .1 13.6 25.4 760.4 780 .9 11 .7 21 .5 765 .2 785 .7 9 .8 17 .6 766.1 786 .6 7.8 13 .7 763.1 783.7 5 .9 9 .8 756.4 776 .9 3.9 6.0 745 .8 766 .2 2.0 3.3 731.4 751 .7 1.3 2 .0 714 .5 734.7 0 .7 0.7 696 .4 716.5 0.0 0.0 677.1 697 .1 0.0 0.0 657 .2 677 .1 0.0 0.0 637 .5 657 .2 0 .0 0.0 617 .9 637 .5 0.0 0.0 598 .4 617 .9 0.0 0 .0 198 .7 213.9 0.0 0.0 183 .7 198.7 0 .0 0 .0 168.9 18 3.7 0.0 0.0 154 .3 168.9 0 .0 0.0 139 .9 154.3 38.9 50 c :8 "' fil ;: > GI I/) 0 ~ w 0 ...J 0 D. u. s "O 0 I-c :J 0 0: ::::> Q D. D. 0 cfs ft cfs 0 .0 272.0C 0 .0 1.3 272.27 u 4 .3 272 .8~ 4 .< 5.1 273 .09 5.1 5.4 273.27 5.4 5.9 273 .51 5.9 6.5 273 .8 6 .5 7 .0 274.U! 7.0 7 .3 274 .2 7 .3 7 .7 274.5 7.7 8 .1 274 .79 8 .1 8.5 275.05 8 .5 8 .8 275 .26 8 .8 9 .0 275 .45 9.0 9.3 275 .62 9.3 9.5 275 .78 9 .5 9 .6 275 .92 9.6 9.8 276 .04 9.8 9 .9 276 .13 9 .9 10.0 276.21 10.0 10 .1 276 .28 10.1 10.1 276 .34 10.1 10.2 276 .39 10.:i 10.2 276.42 10 .2 10 .3 276.44 10.3 10.3 276.46 10 .3 10 .3 276.4€ 10.2 10.3 276 .45 10 .3 10.2 276.43 10.:i 10.2 276.40 10 .2 10.2 276 .3€ 10 .:i 10.1 276 .32 10 .1 10 .1 276 .27 10 .1 10 .0 276.21 10 .0 9.9 276 .1€ 9 .9 9.9 276.10 9 .9 9 .8 276 .0E 9 .8 9.7 275 .99 9.7 7.6 274.4{ 7 .6 7.5 £74.3~ 7.5 7.4 274 .32 7.4 7 .3 274 .25 7 .3 7 .2 274 .19 7.2 Total (Detained 10.3 276.4611 10.3 (.!) ...J :!!: w c( I- I-~ < ~~ 0 23.6 10.0 cfs els 0.0 0 .0 2.4 2.4 4 .7 4 .7 7.1 7.1 9.4 9 .4 11.8 11 .8 14 .1 14 .1 16.5 16.5 18 .8 18 .8 21 .2 21 .2 23.6 23 .6 22 .4 22 .4 21.2 21 .2 20 .0 20 .0 18.8 18 .8 17.7 17 .7 16.5 16 .5 15.3 15 .3 14.1 14 .1 13.0 13.0 11.8 11.8 10 .6 10.6 9.4 9.4 8.2 8.2 7.1 7 .1 5.9 5.9 4 .7 4 .7 3.5 3.5 2.4 2.4 1.2 1.2 0 .0 0 .0 0.0 0.0 0.0 0 .0 0.0 0 .0 0.0 0 .0 0.0 0.0 0.0 0 .0 0 .0 0.0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0 .0 0 .0 Total (Predevelooed 23 .6 11/3/200 5 0533-Dra Ex hibit C4 'It s: c. f Cl e ~ a: N M D.. D.. D.. 't:S < < < < >-::x: 0 0 0 0 Qp 17 .5 13.9 13.2 1.5 Tc 11 .0 10.0 10.0 10 .0 Min inc 1.0 1 .0 1 .0 1 .0 Time cfs cfs cfs cfs 0 .0 0.0 0 .0 0 .0 0 .0 1.0 1.6 1.4 1.3 0 .1 2.0 3 .2 2 .8 2.6 0.3 3.0 4 .8 4.2 3.9 0.4 4 .0 6 .3 5.6 5.3 0 .6 5.0 7.9 7.0 6 .6 0.7 6 .0 9 .5 8.4 7.9 0 .9 7.0 11.1 9.8 9.2 1.0 8.0 12.7 11 .2 10 .5 1.2 9.0 14.3 12 .6 11 .8 1.3 10.0 15.9 13 .9 13 .2 1.5 11 .0 17 .5 13 .3 12 .5 1.4 12.0 16 .7 12.6 11 .8 1.3 13 .0 15 .9 11 .9 11 .2 1.2 14.0 15 .1 11 .2 10.5 1.2 15.0 14 .3 10 .5 9.9 1.1 16.0 13 .5 9 .8 9 .2 1.0 17 .0 12 .7 9.1 8.5 0.9 18 .0 11.9 8.4 7 .9 0 .9 19.0 11.1 7.7 7 .2 0.8 20 .0 10 .3 7.0 6 .6 0 .7 21 .0 9 .5 6 .3 5.9 0.7 22.0 8 .7 5.6 5 .3 0.6 23.0 7.9 4 .9 4.6 0.5 24 .0 7 .1 4.2 3 .9 0.4 25 .0 6 .3 3.5 3.3 0.4 26 .0 5 .6 2 .8 2 .6 0.3 27.0 4 .8 2 .1 2.0 0.2 28 .0 4 .0 1.4 1.3 0 .1 29 .0 3.2 0 .7 0 .7 0.1 30.0 2.4 0 .0 0 .0 0.0 31 .0 1.6 0.0 0 .0 0.0 32 .0 0 .8 0 .0 0 .0 0 .0 33 .0 0.0 0.0 0 .0 0 .0 34 .0 0 .0 0.0 0.0 0 .0 35 .0 0.0 0.0 0.0 0 .0 36 .0 0 .0 0 .0 0 .0 0 .0 37 .0 0.0 0.0 0.0 0 .0 60 .0 0 .0 0 .0 0 .0 0 .0 61 .0 0 .0 0.0 0.0 0 .0 62 .0 0 .0 0.0 0.0 0 .0 63 .0 0.0 0 .0 0 .0 0.0 64.0 0 .0 0.0 0 .0 0 .0 PEAK FLOWS 17.5 13.9 13.2 1.5 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c: 0 a w t. z c: iii + a :E .:. + :::!: c: + 't:S c: 8 ii; U) c: "' "' cfs cfs cfs cfs 0 .0 4.4 0.0 0.0 4 .4 13 .3 1.4 4.4 8 .9 22 .2 5 .0 14 .8 13 .3 31 .1 17 .0 27 .2 17.8 40 .0 36.9 48.1 22.2 48.9 64 .6 76.9 26.7 57.8 99.7 113.5 31 .1 66 .6 143 .0 157.4 35 .5 75 .5 194 .5 209.7 40 .0 84.4 254 .0 270 .0 44.4 89 .0 321 .5 338.4 44 .6 87 .0 392 .9 410 .5 42.4 82 .5 461.6 479 .9 40 .1 78 .1 525 .3 544 .2 37 .9 73 .6 584 .1 603.4 35 .7 69 .2 638 .0 657 .7 33 .5 64 .7 687.1 707 .1 31 .3 60 .3 731 .5 751 .8 29.0 55 .9 771.2 791 .8 26 .8 51 .4 806.2 827 .0 24 .6 47.0 836 .6 857 .6 22 .4 42.5 862.4 883.6 20.2 38 .1 883 .6 904 .9 17 .9 33 .6 900 .3 921.7 15 .7 29.2 912.4 933 .9 13.5 24.8 920.1 941 .6 11.3 20.3 923 .3 944 .8 9.0 15.9 922 .0 943.6 6 .8 11 .4 916.4 937.9 4 .6 7.0 906.3 927.8 2.4 4 .0 891 .9 913 .3 1.6 2.4 874 .6 895.9 0.8 0 .8 855 .9 877.0 0 .0 0.0 835.7 856 .7 0 .0 0 .0 814 .8 835 .7 0 .0 0.0 794 .1 814 .8 0.0 0 .0 773 .5 794.1 0.0 0.0 753 .0 773.5 0 .0 0.0 322 .6 339.6 0 .0 0 .0 305 .9 322 .6 0.0 0 .0 289.4 305.9 0 .0 0 .0 273 .1 289 .4 0 .0 0 .0 257.0 273 .1 44.6 100 c: :8 "' fil := > 41 U) 0 ~ w 0 ...J 0 D.. u.. 'E 't:S c: o~ :I 0 g: 5 0 D.. cfs ft cfs 0 .0 272 .0( 0 .0 1.5 272.31 H 4 .9 273 .00 H 5.1 273 .1 3 5.1 5.6 273.34 5 .6 6 .2 273.63 6 .2 6.9 274 .0C 6 .9 7 .2 274 .2C 7.2 7 .6 274.4l 7 .6 8 .0 274.72 8.0 8 .5 275 .0. 8 .5 8.8 275.27 8 .8 9 .1 275 .51 9 .1 9 .4 275 .74 9 .4 9 .7 275 .94 9 .7 9.9 276.10 9.9 10 .0 276 .24 10.C 10.2 276 .36 10 .2 10 .3 276.48 10 .2 10.4 276.57 10 .4 10 .5 276.66 10 .e 10 .6 276 .73 10 .6 10 .7 276.78 10 .7 10 .7 276 .83 10 .7 10 .7 276.87 10 .7 10 .8 276 .89 10.8 10 .8 276 .9C 10 .E 10 .8 276.90 10.8 10 .8 276 .88 10 .e 10.7 276 .85 10 .7 10 .7 276 .81 10.7 10.6 276.76 10.6 10 .6 276.71 10 .€ 10 .5 276 .65 10 .5 10 .4 276.6C 10.4 10 .4 276 .54 10.4 10 .3 276.48 10 .2 10 .2 276 .42 10 .2 8 .5 275 .02 8.5 8.4 274 .95 8.4 8 .3 274.88 8 .3 8.1 274 .80 8.1 8 .0 274.72 8 .0 Total (Detained 10.8 276.9011 10.8 (.!) ...J ~ w c( ~ < ~ !!! ~~ 0 26.5 10.0 cfs cfs 0.0 0 .0 2 .6 2 .6 5.3 5 .3 7.9 7.9 10 .6 10 .6 13 .2 13 .2 15.9 15 .9 18 .5 18 .5 21 .2 21.2 23 .8 23 .8 26.5 26.5 25 .1 25.1 23 .8 23.8 22.5 22 .5 21.2 21 .2 19.9 19.9 18 .5 18 .5 17 .2 17 .2 15 .9 15 .9 14 .6 14 .6 13 .2 13 .2 11 .9 11 .9 10 .6 10 .6 9.3 9.3 7.9 7 .9 6 .6 6 .6 5 .3 5.3 4 .0 4 .0 2 .6 2 .6 1.3 1.3 0 .0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0.0 0 .0 0 .0 0.0 Q ~Q 0 .0 0.0 0.0 o,Q 0 .0 0.0 Total (Predeveloped 26.5 11/3/200 5 0533-Dra Ex hib it C4 BRENHAM BANK DRAINAGE ANALYSIS November 2005 Prepared for LL ·G · TATI N the l.eart of1he Research Valley By MITCHELL MORGAN ENGINEERS & CONSTRUCTORS 511 UNIVERSITY DRIVE, SUITE 204 COLLEGE STATION, TX 77840 OFF ICE (979) 260-6963 FAX (979) 260-3564 CERTIFICATION "I hereby certify that I am familiar with the adopted ordinances, regulations, standards, and policies of the City of College Station governing development, that these plans have been prepared under my supervision, and that this dra in age plan complies with governing ordinances and regulations to the best of my knowledge." "The site of Brenham Bank , Lot 2A, Block 1 of the Liberty Subdivision does not lie within the blished area of the special flood hazard as established by the current flood insurance y or flood insurance rate map panel number 144C, dated July 2, 1992 ." I .,.a11u~, \\ I) { lf\'J :~;~~--~-~-~~J~''•· / l))/V .:;" G::i ••· J. . ··."'IS' 'I ~·...-~~ ···.•'1 ;' * ... ;~~ ... * ~ ~-··············· .......... : ...... '/. --'1J¥--'-----=..:::..-+1i-=--:-~~...,.....=----!i'.,,__ ........ ,.,.,.~ .' qw.J.. [. l.1 0 RGAN ~ .E., C.F .M1. : . . . .. ····:·····~ · ~-u . r s ·, ·CI:i' I Engineer '1. ">! ·.. ' ·· /1.JJ :t 11 0 · .. -9~-•. ~Q •·• !.ii~ 9 II ~··· .. '-iST EI"-,/-# .:;" '• IS's ........... ~0.: '\,,.fONAl.. €,...---'' :\., ............... Introduction BRENHAM BANK DRAINAGE ANALYSIS The purpose of this drainage report is to present an anal ysis of the necessary drainage infrastructure for the proposed Brenham Bank . This development will be located in Co lleg e Station, at the southwest corner of the intersection of Southwest Parkway and the State Highway 6 East Bypass. The drainage report provides analysis for the infrastructure required to facilitate attenuation and removal of onsite flow . This report includes analysis for currently proposed development of the 4.58 acre Lot 2A as well as the future development to the west of Brenham Bank, contained in postdevelopment drainage areas DA-P1 through DA-P6, shown on Exhibit B. Per the City of College Station Drainage Policy and Design Standards (DPDS) the parameters used for the design and analysis of pre-v. post- development conditions include adherence to the stated zero peak flow rate increase due to development set forth in the guidelines . General location and Description Brenham Bank will be located in College Station, Te xas, at the SH6 and Southwest Parkway intersecti on . The development is located on Lot 2A. Block 1 of the Liberty Subdivision, which is currently undeveloped with the exception of a small access road that runs around the property . Stormwater runoff from the site will be detained in an on-site detention pond. The project location is shown in Exhibit A 1, Project Location Map. Drainage Design Criteria All drainage design is in accordance with the City of College Station DPDS. As such: • Flow calculations are based on the Rational Method with a min im um t im e of concentration of 1 O minutes . • Design rainstorm events consist of the 5-, 10-, 25-, 50-and 100-year frequency storm events in order to analyze the effectiveness of the detention facilities as well as capture conservative peak flow values. All detention pond routing can be found in Exhibit C4. • Flow calculations are based on the rational method using the guidelines prov ided in the DPDS, and can be found in Exhibit CJ . The analysis confluence for this report is identified as the proposed junction box to be located on Southwest Parkway and tying into the existing 24" storm sewer approximately 60 ft to the west of the SH6 frontage road . Achievement of des ign objectives will be based on the effects of the proposed storm drainage system on this junction box . Primary Drainage Basin Description The project site is located within the Wolf Pen Creek Drainage Basin . As demonstrated in Exhibit A2, no portion of the project lies within the regulatory 100-year floodplain per the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) panel 144C, with an effective date of July 2, 1992. The site drainage currently flows across the property in a northeasterly direction and is collected by an existing grate inlet at the corner of SH 6 and Southwest Parkway . \~\Mitchell & Morgan, LLP Stormwater Runoff Analysis General Information Drainage characteristics for this analysis were selected from the DPDS guidelines. Drainage areas were delineated from the on-the-ground topographic survey data. This information can be seen in Exhibit 8 , the Drainage Area Map . ?redevelopment Drainage Analysis Per Exhibit 8, Pre-and Postdevelopment Drainage Area Map, all of Lot 2A drains toward the aforementioned in let at the SH6/Southwest Parkway intersection . Flow entering this inlet drains north through an existing storm sewer system, ultimately draining into Wolf Pen Creek . Runoff calculations were performed using the Rational Method. Approximately 5% of the property is currently impervious cover, with the remainder being wooded and grassy area . Peak runoff values for the predevelopment drainage basin are provided in Exhibit C1, Rational Formula Drainage Area Calculations . Sub-basin areas were based on topographic information provided and largely determined by the location of the bounding access streets . Postdevelopment Drainage Analysis As demonstrated in Exhibit 8, approximately 37% of the lot will remain undeveloped with construction of Brenham Bank as well as a future project (DA-P1) west of the bank to be completed at a later date . For the purposes of this study, it was assumed that the future project loca ted in DA-P1 would have approximately 90% impervious cover . Drainage analysis for the site will assume ultimate development, requiring no rehabilitation to the proposed drainage in fras tructure with the next development on the property . The ultimate development of the basin has approximately 63 % impervious cover because of the amount of space occupied by the detention pond as we ll as the fact that a significant portion of the drainage area is within the TxDOT ROW . The postdevelopment drainage areas have been modified to reflect the drainage patterns resulting from the proposed grading and storm sewer improvements on the site; however, the total drainage basin area is the same for both the pre-and postdevelopment conditions . Proposed grading of the site and detention pond is provided as Exhibit E. Postdevelopment drainage patterns will remain similar to those of predevelopment conditions with a majority of the site draining toward the existing g rate inlet. Flow from Brenham Bank will be directed in the parking lot to a series of grate inlets, and into the proposed detention pond through a series of storm sewer pipes. The proposed storm sewer is shown in Exhibit D and capacity calculations have been provided in Exhibit C2. The remainder of the flow will be directed to the pond by graded slopes . Water will be released from the detention pond through a fifteen inch (15 ") pipe to the existing storm sewer system at th e proposed junction box in the Southwest Parkway ROW. Drainage Facility Design Rational and Storage Indication Curve Modeling As previously mentioned, design flows were calculated using the rational method, as shown in Exhibit C1 . The flows from rational analysis were routed through the detention pond using storage-indication curve rout ing techniques. Stage/Storage, Stage/Discharge, and Storage Indication Curves for the proposed detention pond may be found in Exhibit C3 . Storage-outflow routing was used to determine outflows from the pond to the proposed l:".'.I Mitchell & Morgan, LLP 2 junction box for the 5-, 10-, 25-, 50-, and 100-year frequency storm events, as shown in Exhibit C4. Proposed Storm Drainage Infrastructure A junction box wi ll be constructed along the existing storm sewer line as indicated in Exhibit D in order to provide service from the proposed detention pond . Outflow from the detention pond is controlled by a proposed fifteen inch (15") HOPE headwall and pipe . For the purpose of the calculations an overflow weir was set at 277 . 50 ft; however, the calculati o ns also show that the peak water surface elevation for the 100-year event are below 277.00 ft, al lowing for more than a foot (1 ft.) of freeboard to the top of berm, which has been set at 278 .00 ft. In the event that the storm drain system is clogged, site grading has been established such that flows from the pond will overflow the detention pond berm and enter the storm sewer along Southwest Pa rkway . In addition, the minimum finished floor on the building will be 285 .00 ft., approximately 2 ft. above the Southwest Parkway elevations, allowing adequate overland relief . Drainage Analysis Results As demonstrated in Exhibits C 1 to C4, there are no peak flow rate increases at the study confluence . In fact, there are significant decreases due to the large size of the detention pond, even though we are considering full development of the property in the analysis . The detention pond has been significantly oversized in order to provide enough fill material to place the site and building at a desirable elevat ion . Peak flow rates at the junction box were reduced in all storm frequencies studied , as shown in Table 1 below. The design of the storm sewer system resulted in a 100-year peak flow rate of 10.8 cfs at the Study Point outfall and a 100-year peak water surface in the pond of 276 .90 feet, which provides more than a foot of freeboard for the berm of the detention pond. Development 5-Year Peak 10-Year Peak 25-Year Peak 50-Year Peak 100-Year Peak Flow Conditions Flow (cfs) Flow (cfs) Flow (cfs) Flow (cfs) (cfs) Predevel oi;!ment 16.3 18.2 20.8 23.6 26.5 Postdevelo pment 26.3 29 .5 33 .7 38 .1 42.8 Peak Flow Increase 10.0 11.3 12.9 14.5 16.3 Post-Detention 9 .1 9 .5 10 .0 10.3 10 .8 Peak Fl ow Reduction 7 .2 8.7 10.8 13 .3 15.7 Co nclusion s The development of the Brenham Bank will cause a substantial increase in peak stormwater runoff due to the add ition of a significant amount of impervious cover to the site. The analysis of the proposed storm drainage infrastructure yie lds a picture of the drainage conditions during a substantial rainfall event ensures that no significant flooding will occur on the proposed site. Review of the stormwater analysis ind icates that the drainage design presented in this report will provide ample conveyance and detention to meet the drainage objective of the City of College Station DPDS . 1:::1 Mitchell & Morgan, LLP 3 <( :: w 0 0::: ..J <( <( c u. w w z I-c (!) 0::: <( z <( z <( <( ..J ..J w () <( ::c: z ..J (/) w :!! ..J ..J I- <( (/) > w <( 0::: (!) <( I-<( <( > I-Wz 0::: 0 0::: 0::: <( 0 >w c I-(!) (!) a.. I-0 ..J NO. AC . 0 .45 0 .65 0.95 ft. DA -E1 4.46 4.24 0 .00 0 .22 2 .11 300 .0 ,_ ,_ -,_ , __ -- DA-P 1 1.23 0 .11 0.00 1 .12 1 .11 100 .0 -DA-P 2 1.78 1.28 0 .00 0 .50 1.05 22 0 .0 --- ----- D A-P3 0 .12 0 .00 0 .00 0 .12 0 .12 0 .0 --- --DA-P4 0 .41 0 .00 0 .00 0 .4 1 0 .39 0 .0 ----- DA-P S 0.53 0 .24 0 .00 0 .28 0 .38 0 .0 -DA-P6 0 .39 0 .00 0 .00 0 .39 0 .37 0 .0 EXHIBIT C1 Rationa l Formula Drainage Area Calculati ons BRENHAM BANK :: 0 :: :: ..J u. 0 0 c ..J ..J z u. u. >- <( 0::: ::c: 0::: I-u ..J w I-w 0 I-u 0::: ..J I-(!) I-..J 0 I- w ..J I-z I-..J ..J u w > <( ::::> w ::::> <( w ra (/) N 0 u. (!) ..J (!) u. > () ::::> !:::! 0 !!2 ft. ft. ft. ft/s m i n min In /Hr cfs In/H r 2 .0 50 .0 0 .5 0 .6 9 .1 10.0 6 .33 13.4 7 .7 ,__ 2 .0 450 .0 4 .0 1 .6 5 .7 10.0 6 .3 3 7 .0 7 .7 1 .0 100.0 7 .0 0 .7 8 .0 10 .0 6 .33 6 .6 7 .7 - - ------0 .0 50 .0 2 .0 4 .0 0 .2 10.0 6.33 0 .7 7 .7 -0 .0 50 .0 2 .0 4 .0 0 .2 10.0 6 .33 2.4 7 .7 ,_ ------0 .0 50 .0 2 .0 4 .0 0 .2 10.0 6 .33 2.4 7 .7 0 .0 50 .0 2 .0 4 .0 0 .2 10.0 6 .33 2 .4 7.7 0 II) II) 0 ..-II) N 0 :!: 0 !:::! 0 cfs In /Hr cfs In/Hr cfs 16 .3 8 .6 18 .2 9 .9 20 .8 -. -8 .6 8.6 9 .6 9 .9 11 .0 8 .1 8.6 9 .1 9 .9 10.4 0 .9 8 .6 1 .0 9 .9 1 .1 3 .0 8 .6 3 .3 9 .9 3.8 ,_ 2 .9 8 .6 3 .3 9 .9 3 .7 2 .9 8 .6 3 .2 9 .9 3 .7 0 0 0 0 0 II) 0 ..- !!2 0 :!: 0 In /Hr cfs In/Hr cfs 11.1 23 .6 12.5 2 6 .5 ----- -11 .1 11 .1 11 .1 11 .1 11 .1 11 .1 12.4 12 .5 13 .9 11 .7 12 .5 13.2 1 .3 12 .5 1 .5 4 .3 -12 .5 _ _1.8 _ 4.2 4 .2 12.5 4 .7 12 .5 4 .7 1113/2005 0533-D ra EXH IB IT C1 0 z ~ ~ ..::I ~ # DA-E1 DA-P4 DA-P5 DA-P6 ~ ~ ..::I ~ 0 ~ # Grate POND DA-P4 DA-PS < u ..::I < ~ 0 ~ Ac. 2.1 1.1 0.8 0.4 (,) ~ min 10.0 10.5 10.1 10.0 E lo. 0 -r.r.i = -~ (I} Q,j ~ yr 100 100 100 100 "O ~ Q,j 0 --~ ~ . ..., = "O Oil t<: ·-= (I} ~~ cfs 26.5 14.0 9.4 4.7 EXHIBIT C2 Pipe Capacity Calculations BRENHAM BANK -I< ~ 0 "O ~ Q,j -= (I} Oil = ·-• ..., (I} "O Q,j <~ cfs 26.5 17.5 11.7 5.8 (I} Q,j Q.. i:C ..... 0 0 z # Q,j Q.. i:C lo. Q,j ~ ~ 0 ~ cfs 26.5 17.5 11.7 5.8 =-I< 0 -I< ·-Q,j ti Q.. ·-0 lo. -~ r.r.i O/o 0.09 0.71 0.73 0.48 Q,j Q.. 0 00 Q,j Q.. i:C O/o 0.34 0.75 0.75 0.75 ~ ~ r.r.i 36 21 18 15 J ~ fps 7.2 7.4 6.7 5.9 -I< .0 ·;::; ~ Q.. ~ u cfs 50.7 17.9 11.9 7.3 == ~ 0 z ~ ..::I 37 165 43 Q,j E E= "Z ~ lo. ~ min 0.00 0.08 0.41 0.12 .......-----"O = ~ @) (,) ~ min 10.00 10.61 10.53 10.12 11/3/2005 0533-Dra Exhibit C2 - EXHIBIT C3 Stage/Storage -Stage/Discharge -Storage Indication Curves BRENHAM BANK Elevation Area Area (ft.) (sf.) (acres) 272 .0 0 0.000 273.0 863 0 .020 274.0 5608 0.129 275 .0 7538 0 .173 276.0 9679 0 .222 277 .0 11959 0 .275 278 .0 14516 0 .333 279 .0 15000 0 .344 280.0 15000 0.344 BRENHAM BANK Storage Indication Curve 3000 ~----~--------. ' ' I t ' ' ' ' ~:=~· ..• ~ :a 1000 ' : : : : ~ ' . ' ' 500 ; ········1···--··· .. ·~··········t·······---~··········· 0 4 : : : 50 100 150 200 250 Discharge (cfs) Inc . Volm . (ac .-ft .) 0 .000 0 .007 0 .066 0 .150 0 .197 0 .248 0 .303 0 .339 0 .344 Volume Outlet 1 Outlet 2 Total (ac .-ft .) Invert Elev . (ft.) 272 277 .5 Flow Orifice Dia. (in .) or Weir Length (ft .) 15 20 Outfall Orifice ( cfs) Orifice ( cfs) (cfs) 0 .000 0 .007 0 .073 0 .223 0.420 0 .668 0.972 1.311 1.655 BRENHAM BANK Stage-Storage Curve ---------.L •.•...•... L .....••••• J••••·--------------' . ' ' ' ' ' ' ' ' ' ----------~ ----------. ----------. ----------. ---------' ' . ' ' ' ' ' ' - -- - ---- - -~ - - --- - - - - -~ - - - - - - - - - - ! - - - - --- --J - - - - - - - - - -' . . ' ' ' . ' ' ' ' ' ' ' ' I ----------·----------·----------·---------·---------- ' ' ' ' I ' ' I ' ' ' ' ' ' ------·---r----······r·--------· ----------,•••••----- ' 0 I I ' ' . ' ' ' ----------~ ----------. ----. ' 0 .00 4 .87 6.89 8.44 9 .75 10.90 11.94 12 .90 13.79 0 .00 0 .00 0.00 4 .87 0.00 6.89 0 .00 8.44 0 .00 9 .75 0.00 10 .90 21.21 33 .15 110 .23 123 .12 237.17 250 .96 BRENHAM BANK Stage-Discharge Curve 300 ,..---------------. 250 ~ ••••••• ·····•·····---·---------••L---·--•·-• •-•••-··•• . ' ' . ' ' ' ' ' ' ' ' 2.. 200 ···········:···········:···········~·········· •·· ...... . Cl> : : : ~ 150 ----------~-----------: ... --------~--------------------m : : : .s::: : : : ~ 100 ··········:···········;···········:·········· ......... . Ci ' ' 50 .......... ; ......... --~· .... ···---~---· .. . . .. . ....... . 270 272 274 276 278 280 270.0 272 .0 274 .0 276 .0 278 .0 280 .0 Elevation (msl) Elevation (msl) 11/3/2005 0533 -Dra Exh ibit C3 -- -.I:. a. !! Cl "Ot N M ~ ..... Q. Q. Q. Q. "C cl: cl: cl: cl: >. J: c c c c Qp 10 .7 8 .6 8.1 0.9 Tc 11 .0 10.0 10 .0 10 .0 Min inc 1.0 1 .0 1.0 1.0 Time cfs cfs cfs cfs 0.0 0 .0 0.0 0 .0 0 .0 1.0 1.0 0 .9 0.8 0 .1 2.0 1.9 1.7 1.6 0.2 3.0 2 .9 2.6 2.4 0.3 4 .0 3.9 3.4 3 .2 0 .4 5.0 4 .9 4.3 4 .0 0 .4 6.0 5 .8 5 .1 4 .8 0 .5 7.0 6 .8 6 .0 5.7 0.6 8.0 7 .8 6 .9 6 .5 0.7 9.0 8 .8 7 .7 7.3 0.8 10 .0 9.7 8 .6 8 .1 0 .9 11.0 10 .7 8 .1 7 .7 0.9 12 .0 10 .2 7.7 7 .3 0 .8 13 .0 9.7 7.3 6.9 0 .8 14 .0 9 .2 6 .9 6 .5 0 .7 15.0 8.8 6.4 6 .1 0.7 16 .0 8 .3 6.0 5 .7 0 .6 17 .0 7.8 5.6 5.3 0 .6 18 .0 7 .3 5 .1 4 .8 0.5 19.0 6 .8 4 .7 4 .4 0.5 20 .0 6.3 4 .3 4 .0 0 .4 21 .0 5.8 3.9 3.6 0.4 22 .0 5.4 3.4 3.2 0 .4 23 .0 4 .9 3.0 2.8 0.3 24 .0 4.4 2 .6 2 .4 0.3 25 .0 3.9 2 .1 2.0 0.2 26.0 3.4 1.7 1.6 0 .2 27 .0 2.9 1.3 1.2 0 .1 28 .0 2.4 0 .9 0 .8 0.1 29 .0 1.9 0.4 0.4 0 .0 30 .0 1.5 0 .0 0.0 0 .0 31 .0 1.0 0.0 0.0 0 .0 32 .0 0 .5 0 .0 0.0 0 .0 33.0 0.0 0.0 0 .0 0 .0 34 .0 0 .0 0 .0 0 .0 0 .0 35.0 0 .0 0 .0 0.0 0.0 36 .0 0 .0 0.0 0 .0 0 .0 37.0 0.0 0.0 0.0 0.0 60.0 0.0 0 .0 0.0 0 .0 61 .0 0.0 0.0 0.0 0 .0 62 .0 0.0 0 .0 0 .0 0 .0 63 .0 0.0 0 .0 0.0 0.0 64 .0 0 .0 0 .0 0 .0 0.0 PEAK FLOWS 10.7 8.6 8.1 0.9 EXHIBITC4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c: c 0 w t. z c: Cii ..... 0 '.:!:! + ~ + :IE c: + c: 8 ~ !!! c: cfs cfs cfs cfs 0.0 2 .7 0 .0 0 .0 2 .7 8.2 0.9 2.7 5 .5 13 .6 3 .0 9.1 8.2 19 .1 6 .8 16.6 10 .9 24 .5 15 .6 25 .8 13 .6 30 .0 29.4 40 .2 16.4 35 .5 47.8 59.4 19 .1 40 .9 70.7 83.2 21.8 46.4 97 .8 111.6 24.5 51 .8 130 .0 144 .2 27 .3 54.6 167.0 181 .8 27.4 53 .4 206 .3 221 .6 26 .0 50.6 243.8 259 .7 24 .6 47 .9 278 .1 294 .5 23 .3 45.2 309.3 326.0 21 .9 42 .5 337 .4 354.4 20.5 39 .7 362.5 379.8 19 .2 37 .0 384 .7 402.2 17 .8 34 .3 404 .0 421 .7 16.5 31 .6 420 .5 438.3 15 .1 28 .8 434 .0 452 .0 13.7 26 .1 444 .8 462.9 12.4 23 .4 452 .8 470.9 11.0 20.6 457.9 476 .1 9 .6 17.9 460.4 478.6 8.3 15 .2 460.1 478 .3 6 .9 12 .5 457 .1 475.3 5.6 9.7 451 .4 469 .6 4 .2 7 .0 443 .1 461 .2 2 .8 4 .3 432 .2 450 .1 1.5 2.4 418 .6 436 .5 1.0 1.5 403.4 421 .1 0 .5 0 .5 387.3 404 .8 0.0 0.0 370.4 387 .8 0.0 0 .0 353 .2 370 .4 0.0 0.0 336.1 353.2 0 .0 0 .0 319 .2 336.1 0 .0 0 .0 302.5 319 .2 0 .0 0 .0 1.3 3.9 0 .0 0 .0 0.4 1.3 0.0 0.0 0 .1 0.4 0.0 0.0 0.0 0 .1 0 .0 0 .0 0 .0 0 .0 27 .4 5 c: ~ .. ~ s: > Cl> (/) 0 ~ w 0 ..J 0 Q. u. 'E "C c: 0 I- 6 0 g: 5 Q. cfs ft cfs 0 .0 272 .01 U.l 0.9 272 .19 0 .9 3 .1 272 .6' 3 .1 4 .9 273 .02 4 .9 5 .1 273 .1. 5.1 5.4 273 .26 5.4 5.8 273.4E 5.8 6.3 273 .70 6 .3 6 .9 273 .91 6 .9 7.1 274 .14 7.1 7.4 274 .31 7.4 7.7 274 .49 7.7 7 .9 274 .67 7 .9 8.2 274 .83 8 .< 8.4 274 .91 8.4 8.5 275.08 8.5 8 .7 275 .1€ 8.7 8.8 275 .24 8] 8 .8 275 .31 8 .8 8.9 275.37 8.9 9 .0 275 .42 9 .0 9.0 275.45 9.0 9.1 275.48 9 .1 9.1 275.50 9.1 9.1 275.5 1 9 .1 9.1 275 .51 9.1 9 .1 275 .50 9 .1 9 .1 275.48 9.1 9 .0 275.45 9 .0 9 .0 275 .41 9.0 8 .9 275 .36 8.9 8.8 275 .31 8.8 8 .8 275 .2' 8.8 8.7 275 .H 8 .7 8 .6 275.1' 8.6 8.5 275 .07 8 .5 8 .5 275 .01 8.5 8 .3 274 .94 8.3 1.3 272 .2i 1.3 0 .4 272 .09 0.4 0.1 272 .0: 0 .1 0.0 272 .01 0 .0 0 .0 272.0C 0 .0 Total (Detained 9.1 275.5111 9.1 (.!) ..J ~ w <( I- cl: I-!a g~ c 16 .3 10 .0 cfs cfs 0 .0 0 .0 1.6 1.6 3.3 3.3 4 .9 4 .9 6 .5 6 .5 8 .1 8.1 9 .8 9.8 11.4 11 .4 13.0 13 .0 14.6 14 .6 16.3 16 .3 15 .4 15.4 14 .6 14 .6 13.8 13 .8 13.0 13 .0 12.2 12.2 11 .4 11.4 10 .6 10 .6 9 .8 9 .8 8.9 8.9 8.1 8.1 7.3 7.3 6 .5 6 .5 5.7 5.7 4.9 4 .9 4.1 4 .1 3.3 3 .3 2.4 2 .4 1.6 1.6 0.8 0 .8 0 .0 0 .0 0.0 0 .0 0 .0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0 .0 0 .0 0 .0 0.0 Q.:9 0 .0 0.0 0.0 0.0 0 .0 0.0 Total (Pre developed 16 .3 11 /3/2005 0533-0ra Exhibit C4 -.&; c. !!! Cl !:! • ... N M CL CL CL CL 'C cl: cl: cl: cl: >-:c c c c c Qp 12.0 9 .6 9 .1 1.0 Tc 11 .0 10.0 10.0 10 .0 Min inc 1.0 1.0 1.0 1.0 Time cfs cfs cfs cfs 0.0 0.0 0 .0 0 .0 0 .0 1.0 1.1 1.0 0 .9 0.1 2 .0 2 .2 1.9 1.8 0 .2 3.0 3.3 2.9 2 .7 0.3 4 .0 4.4 3.8 3 .6 0.4 5.0 5.5 4 .8 4 .5 0.5 6 .0 6 .6 5 .8 5.4 0 .6 7.0 7.7 6 .7 6 .3 0.7 8.0 8 .7 7 .7 7.3 0.8 9.0 9.8 8 .7 8.2 0 .9 10 .0 10 .9 9.6 9 .1 1.0 11.0 12 .0 9 .1 8.6 1.0 12 .0 11 .5 8 .7 8 .2 0 .9 13 .0 10 .9 8 .2 7 .7 0 .9 14 .0 10.4 7 .7 7 .3 0 .8 15 .0 9.8 7.2 6 .8 0 .8 16 .0 9 .3 6.7 6.3 0 .7 17 .0 8 .7 6 .2 5.9 0.7 18 .0 8 .2 5.8 5.4 0 .6 19 .0 7.7 5.3 5.0 0.6 20 .0 7 .1 4 .8 4.5 0.5 21 .0 6.6 4 .3 4 .1 0.5 22 .0 6 .0 3 .8 3.6 0.4 23.0 5.5 3.4 3.2 0.4 24.0 4 .9 2.9 2 .7 0 .3 25 .0 4.4 2.4 2.3 0.3 26.0 3.8 1.9 1.8 0 .2 27.0 3.3 1.4 1.4 0.2 28 .0 2 .7 1.0 0.9 0 .1 29.0 2.2 0.5 0.5 0 .1 30 .0 1.6 0.0 0 .0 0 .0 31 .0 1.1 0.0 0.0 0 .0 32.0 0 .5 0 .0 0 .0 0.0 33.0 0 .0 0.0 0.0 0 .0 34 .0 0.0 0 .0 0 .0 0 .0 35 .0 0.0 0.0 0.0 0 .0 36.0 0 .0 0.0 0 .0 0 .0 37 .0 0.0 0.0 0.0 0 .0 60 .0 0.0 0 .0 0 .0 0.0 61 .0 0.0 0 .0 0.0 0.0 62 .0 0 .0 0 .0 0 .0 0 .0 63 .0 0.0 0 .0 0.0 0.0 64 .0 0 .0 0 .0 0 .0 0 .0 PEAK FLOWS 12.0 9.6 9.1 1.0 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c c a w t. z c iii ... a :!;! + '5 ... :Ii: c + + c 8 iC ~ c cfs cfs cfs cfs 0 .0 3 .1 0 .0 0 .0 3.1 9.2 1.0 3.1 6 .1 15.3 3.3 10.2 9 .2 21.4 8.7 18.6 12.2 27.6 19 .7 30 .1 15 .3 33.7 36 .2 47.3 18.4 39.8 57 .9 69 .9 21 .4 45.9 84 .5 97 .7 24.5 52.0 116.4 130.4 27 .6 58.2 153 .9 168.4 30.6 61.3 196 .8 212.0 30.7 59.9 242 .3 258.2 29.2 56.9 285.8 302 .3 27 .7 53 .8 325 .7 342.7 26 .1 50.7 362.2 379 .5 24 .6 47 .7 395 .3 412 .9 23 .1 44 .6 425 .1 443 .0 21 .5 41 .5 451 .5 469 .7 20 .0 38 .5 474 .7 493 .1 18 .5 35.4 494 .7 513.2 16.9 32.4 511 .5 530 .1 15 .4 29.3 525 .0 543 .8 13.9 26 .2 535.4 554.3 12.4 23.2 542.7 561.7 10.8 20.1 546 .9 565.9 9.3 17 .1 548.0 567 .0 7.8 14 .0 546 .0 565.0 6 .2 10.9 541 .1 560 .0 4 .7 7.9 533 .1 552 .0 3.2 4 .8 522 .2 541 .0 1.6 2 .7 508.4 527 .0 1.1 1.6 492 .6 511 .1 0.5 0.5 475.9 494 .2 0 .0 0 .0 458.2 476.4 0.0 0 .0 440 .2 458.2 0 .0 0.0 422 .3 440.2 0 .0 0.0 404 .6 422 .3 0.0 0 .0 387.1 404 .6 0.0 0 .0 43 .1 54 .5 0.0 0.0 32.2 43 .1 0.0 0.0 21 .7 32 .2 0.0 0.0 11.7 21 .7 0 .0 0 .0 3 .8 11 .7 30.7 10 c ~ "' ~ ;: > Cl> en o :c w 0 ...J 0 CL u.. s 'C c 0 I- :i 0 n:: ::> 0 CL CL 0 cfs ft cfs 0 .0 272.0C O.C 1.0 272.21 1.0 3.4 272.70 3.4 5.0 . 273 .04 5.0 5 .2 273 .16 5.2 5.5 273 .33 5.t 6 .0 273.56 6 .0 6.6 273 .85 6.E 7 .0 274.08 7 .0 7.3 274 .25 7 .~ 7 .6 274.45 7 .6 7.9 274 .66 7.9 8 .2 274 .86 8 .2 8 .5 275.03 8.5 8.7 275 .16 8 .7 8.8 275 .28 8.f 8 .9 275 .38 8 .~ 9.1 275.48 9.1 9 .2 275 .56 9 .2 9.3 275 .63 9.3 9 .3 275 .69 9 .3 9 .4 275 .73 9.4 9.4 275 .77 9.4 9.5 275 .80 9.5 9 .5 275 .81 9 .5 9.5 275 .81 9.5 9 .5 275 .81 9 .5 9.5 275 .79 9.5 9.4 275 .76 9.4 9.4 275.72 9.4 9 .3 275 .68 9.3 9 .3 275.62 9.3 9.2 275 .56 9.2 9 .1 275 .50 9.1 9.0 275.44 9.0 8.9 275.37 8.9 8 .9 275.31 8 .9 8.8 275 .25 8.8 5.7 273 .41 5.7 5.5 273 .29 5.5 5 .2 273.18 5 .2 5.0 273 .07 5.0 3.9 272.81 3 .9 Total (Detained 9.5 275.8111 9.5 <.? ...J :!!: w ct I- cl: I-!!? ~~ c 18.2 10 .0 cfs cfs 0.0 0 .0 1.8 1.8 3.6 3.6 5.5 5.5 7 .3 7 .3 9.1 9.1 10 .9 10 .9 12 .8 12.8 14 .6 14 .6 16.4 16.4 18 .2 18.2 17 .3 17 .3 16.4 16.4 15.5 15 .5 14.6 14 .6 13.7 13 .7 12 .8 12 .8 11 .9 11 .9 10 .9 10.9 10 .0 10.0 9.1 9 .1 8.2 8.2 7.3 7.3 6.4 6 .4 5.5 5 .5 4 .6 4 .6 3.6 3.6 2.7 2 .7 1.8 1.8 0.9 0.9 0 .0 0 .0 0.0 0 .0 0.0 0 .0 0.0 0 .0 0.0 0.0 0.0 0.0 0 .0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 .0 Total (Predeveloped 18.2 11 /3/2005 0533-Dra Exhibit C4 -.= Q. ~ Cl e ..,. a: N M a.. a.. a.. "O ci: ci: ci: ci: >. :i:: c c c c Qp 13 .7 11.0 10 .4 1.1 Tc 11 .0 10.0 10.0 10 .0 Min inc 1.0 1.0 1.0 1.0 Time cfs cfs cfs cfs I 0 .0 0 .0 0 .0 0 .0 0 .0 1.0 1.2 1.1 1.0 0.1 2 .0 2.5 2 .2 2.1 0 .2 3.0 3.7 3 .3 3.1 0.3 4 .0 5 .0 4 .4 4 .1 0 .5 5.0 6 .2 5 ,5 5.2 0.6 6.0 7 .5 6.6 6.2 0 .7 7.0 8 .7 7.7 7.2 0.8 8.0 10.0 8 .8 8 .3 0 .9 9 .0 11 .2 9.9 9.3 1.0 10.0 12 .5 11 .0 10 .4 1 .1 11.0 13 .7 10.4 9.8 1.1 12.0 13.1 9.9 9.3 1.0 13.0 12.5 9.3 8.8 1.0 14 .0 11 .9 8 .8 8.3 0 .9 15.0 11 .2 8.2 7.8 0 .9 16 .0 10 .6 7 .7 7 .2 0 .8 17 .0 10.0 7 .1 6 .7 0 .7 18 .0 9 .4 6 .6 6 .2 0.7 19 .0 8.7 6 .0 5.7 0 .6 20 .0 8 .1 5 .5 5.2 0 .6 21.0 7.5 4 .9 4 .7 0 .5 22 .0 6.9 4.4 4.1 0 .5 23 .0 6 .2 3 .8 3.6 0.4 24 .0 5.6 3 .3 3 .1 0.3 25 .0 5.0 2.7 2.6 0.3 26 .0 4 .4 2 .2 2 .1 0.2 27 .0 3.7 1 .6 1.6 0.2 28 .0 3 .1 1.1 1.0 0.1 29.0 2.5 0.5 0.5 0.1 30.0 1.9 0 .0 0 .0 0.0 31 .0 1.2 0 .0 0 .0 0.0 32 .0 0 .6 0 .0 0.0 0.0 33 .0 0 .0 0.0 0.0 0.0 34 .0 0.0 0.0 0.0 0 .0 35.0 0 .0 0.0 0.0 0.0 36.0 0 .0 0.0 0.0 0 .0 37 .0 0.0 0 .0 0.0 0 .0 60.0 0 .0 0.0 0 .0 0 .0 61 .0 0 .0 0.0 0.0 0 .0 62 .0 0.0 0 .0 0 .0 0 .0 63 .0 0.0 0.0 0.0 0 .0 64 .0 0.0 0 .0 0 .0 0.0 PEAK FLOWS 13 .7 11 .0 10.4 1.1 EXHIBITC4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c c 0 w !. z c iii ..... 2 :!;! + + :Ii: c + "O c 8 ~ ~ c cfs cfs I cfs I cfs 0 .0 3 .5 0 .0 0.0 3.5 10 .5 1.1 3.5 7 .0 17 .5 3.8 11 .6 10.5 24.5 11.2 21 .3 14 .0 31 .5 25 .1 35 .7 ---17 .5 38.5 45 .1 56 .6 21 .0 45.5 71 .0 83 .6 24 .5 52.5 102 .6 116.4 28 .0 59.4 140.7 155.1 31 .5 66.4 185 .1 200 .1 35 .0 70 .1 235.8 251.5 35 .1 68 .4 289 .4 305 .9 33 .3 64.9 340.7 357.8 31 .6 61 .4 388.1 405 .6 29 .8 57 .9 431 .6 449 .5 28 .1 54 .5 471 .2 489.5 26.4 51.0 507.0 525 .7 24 .6 47 .5 539 .0 558.0 22 .9 44 .0 567 .3 586 .5 21 .1 40 .5 591 .8 611 .3 19.4 37.0 612.7 632 .3 17 .6 33 .5 630 .0 649 .7 15 .9 30 .0 643 .7 663 .5 14.1 26 .5 653.8 673.7 12.4 23 .0 660.4 680 .3 10 .6 19 .5 663 .5 683.4 8.9 16.0 663.1 683 .0 7.1 12 .5 659 .2 679.1 5.4 9.0 65 1.9 671 .7 3.6 5.5 641 .1 660 .9 1.9 3 .1 626 .9 646 .6 1.2 1.9 610.5 630 .0 0 .6 0 .6 592 .9 612 .4 0 .0 0.0 574.3 593 .6 0 .0 0 .0 555 .2 574 .3 0.0 0 .0 536 .3 555 .2 0.0 0 .0 517 .6 536.3 0 .0 0.0 499.0 517.6 0.0 0 .0 122.2 136 .4 0.0 0 .0 108 .3 122.2 0 .0 0.0 94 .7 108.3 0 .0 0 .0 81 .7 94.7 0.0 0 .0 69 .2 81 .7 35.1 25 c :8 Ill ffi s: > Cl> U) 0 :c iii 0 ...J 0 0.. LL s "O c 0 I-:::s 0 0:: ::> 0 a.. a.. 0 cfs ft cfs 0 .0 272 .0( 0 .l 1.2 272 .2< 1.2 3 .9 272 .8( 3.9 5,0 273 .07 5 .0 5 .3 273.2. 5 .3 5.7 273 .43 5.7 6 .3 273.7( 6 .' 6.9 274 .02 ti .~ 7 .2 274 .H 7 .• 7.5 274.4( 7.~ 7 .9 274 .6 7.9 8.3 274 .88 8.3 8 .6 275.09 8.6 8 .8 275 .25 8 .l 9 .0 275.41 9 .( 9.2 275.55 9 .• 9 .3 275 .67 9 ., 9 .5 275 .78 9 .~ 9 .6 275 .88 9 .€ 9 .7 275 .97 9.7 9 .8 276 .03 9 .8 9.8 276 .08 9 .f 9 .9 276 .1. 9 .~ 9.9 276 .15 9.9 9.9 276 .11 9.9 10.0 276.18 10 .0 9 .9 276 .17 9 .~ 9.9 276 .16 9.9 9 .9 276 .14 9.9 9.9 276.1 1 9.9 9 .8 276 .07 9.8 9.8 276 .03 9.8 9 .7 275.97 9.7 9.6 275 .91 9.6 9.5 275.84 9.5 9.5 275 .77 9.5 9.4 275.71 9.4 9.3 275.64 9.3 7 .1 274 .11 7 .1 7 .0 274 .04 7 .0 6 .8 273 .9e 6 .8 6 .5 273.82 6.5 6.3 273.68 6.3 Total (Detained 10.0 276.18 10.0 (.!) ...J :ii!: w ct I- ci: I-!!! ~~ c 20.8 10 .0 cfs I cfs 0.0 0.0 2.1 2.1 4.2 4 .2 6 .3 6 .3 8.3 8 .3 10 .4 10 .4 12 .5 12 .5 14.6 14 .6 16 .7 16 .7 18 .8 18.8 20.8 20 .8 19.8 19.8 18 .8 18 .8 17.7 17.7 16.7 16.7 15.6 15 .6 14 .6 14 .6 13 .5 13.5 12.5 12 .5 11 .5 11 .5 10 .4 10 .4 9.4 9.4 8.3 8 .3 7 .3 7.3 6 .3 6 .3 5.2 5.2 4 .2 4 .2 3.1 3.1 2 .1 2 .1 1.0 1.0 0 .0 0 .0 0.0 0 .0 0.0 0.0 0.0 0.0 0.0 0 .0 0.0 0.0 0 .0 0 .0 0 .0 0.0 0 .0 0 .0 0.0 0.0 0.0 0 .0 0.0 0 .0 0 .0 0 .0 Total (Predeveloped 20 .8 11 /3/2005 0533-Dra Ex hibit C4 -.r:. c. f! Cl e "'" ... N M ll. ll. ll. ll. "C ci: ci: ci: ci: >. ::i: c c c c Qp 14.7 12 .4 11 .7 1.3 Tc 11.0 10.0 10.0 10.0 Min inc 1.0 1.0 1.0 1.0 Time cfs I cfs cfs cfs 0 .0 0 .0 0 .0 0 .0 0 .0 1.0 1.3 1.2 1.2 0 .1 2 .0 2 .7 2 .5 2 .3 0.3 3.0 4 .0 3.7 3 .5 0 .4 4 .0 5.4 5.0 4.7 0 .5 5.0 6 .7 6 .2 5.9 0.6 6 .0 8.0 7.4 7 .0 0 .8 7.0 9.4 8.7 8 .2 0.9 8.0 10 .7 9 .9 9.4 1.0 9 .0 12 .0 11.2 10 .5 1.2 10 .0 13.4 12.4 11 .7 1.3 11 .0 14 .7 11 .8 11.1 1.2 12 .0 14 .1 11 .2 10 .5 1.2 13 .0 13.4 10 .6 10.0 1.1 14 .0 12 .7 9 .9 9 .4 1.0 15.0 12 .0 9 .3 8.8 1.0 16 .0 11.4 8 .7 8 .2 0 .9 17.0 10.7 8.1 7.6 0 .8 18 .0 10.0 7.4 7.0 0 .8 19 .0 9.4 6 .8 6.4 0.7 20.0 8 .7 6 .2 5.9 0.6 21.0 8 .0 5.6 5.3 0.6 22.0 7.4 5.0 4.7 0 .5 23 .0 6.7 4 .3 4.1 0.5 24.0 6 .0 3 .7 3.5 0.4 25 .0 5.4 3.1 2.9 0 .3 26 .0 4 .7 2.5 2 .3 0 .3 27 .0 4 .0 1.9 1.8 0 .2 28 .0 3.3 1.2 1.2 0 .1 29.0 2.7 0.6 0.6 0.1 30 .0 2 .0 0.0 0.0 0 .0 31.0 1.3 0.0 0.0 0 .0 32 .0 0 .7 0.0 0 .0 0 .0 33 .o· 0 .0 0.0 0.0 0 .0 34 .0 0.0 0 .0 0.0 0 .0 35.0 0.0 0 .0 0.0 0 .0 36.0 0.0 0 .0 0 .0 0 .0 37 .0 0.0 0 .0 0.0 0 .0 60 .0 0 .0 0 .0 0 .0 0 .0 61 .0 0 .0 0 .0 0.0 0.0 62.0 0 .0 0 .0 0 .0 0 .0 63 .0 0.0 0 .0 0.0 0.0 64 .0 0 .0 0 .0 0 .0 0 .0 PEAK FL OWS 14.7 12.4 11.7 1.3 EXHIBITC4 Proposed Detention Pond Routing BRENHAM BA NK D.A. # Pond Routing EVENT= c: c a w t. z c: iii + a ~ ;; ... ~ c: + + c: 8 ~ !!? c: cfs cfs cfs cfs 0 .0 3 .9 0 .0 0 .0 3.9 11.6 1.3 3.9 7 .8 19.4 4 .2 12 .9 11 .6 27 .2 13 .5 23 .6 15 .5 34 .9 29.8 40.6 19 .4 42 .7 52.9 64.7 23 .3 50.4 82.5 95.6 27 .2 58 .2 118 .9 133.0 31 .0 66 .0 162.4 177.1 34 .9 73 .7 213 .0 228.4 38 .8 77.7 270.5 286 .7 38.9 75.8 331 .1 348.1 36 .9 71 .9 389 .4 406.9 35.0 68.0 443 .2 461 .3 33 .1 64 .2 492 .8 511.3 31.1 60.3 538 .0 556 .9 29 .2 56.4 579 .0 598.3 27.2 52 .5 615 .8 635 .4 25 .3 48 .6 648 .5 668.3 23.4 44 .8 677.2 697.2 21.4 40.9 701 .8 721.9 19.5 37 .0 722.4 742.7 17 .5 33 .1 739 .0 759.4 15 .6 29.2 751 .6 772.1 13 .6 25.4 760 .4 780.9 11 .7 21 .5 765 .2 785.7 9 .8 17 .6 766 .1 786 .6 7 .8 13.7 763.1 783 .7 5.9 9.8 756.4 776 .9 3.9 6.0 745 .8 766.2 2.0 3.3 731.4 751.7 1.3 2.0 714 .5 734 .7 0.7 0 .7 696.4 716.5 0 .0 0.0 677.1 697 .1 0 .0 0.0 657 .2 677 .1 0.0 0 .0 637.5 65 7 .2 0 .0 0 .0 617 .9 637 .5 0.0 0.0 598 .4 617.9 0 .0 0 .0 198 .7 213 .9 0 .0 0.0 183 .7 198.7 0 .0 0.0 168 .9 183 .7 0 .0 0.0 154 .3 168.9 0 .0 0 .0 139 .9 154 .3 38 .9 50 c: :8 "' fil ~ > GI VJ 0 :i: iii 0..J 0 ll. LL s "C 0 I-c: ::i 0 0:: ::> 0 ll. ll. 0 cfs ft cfs 0.0 272 .0C 0 .0 1.3 272.27 1.3 4 .3 272 .8S 4.3 5.1 273.09 5.1 5.4 273 .2i 5.4 5 .9 273 .51 5.9 6.5 273.8< 6 .5 7.0 274.09 7.0 7.3 274 .2S 7.3 7.7 274.53 7.7 8 .1 274 .7S 8.1 8.5 275.05 8.5 8 .8 275 .2E 8.8 9.0 275.45 9 .0 9 .3 275 .6i 9.3 9.5 275 .78 9 .5 9 .6 275 .9. 9.6 9 .8 276 .04 9.8 9 .9 276.1~ 9.9 10.0 276 .21 10 .0 10.1 276 .2~ 10 .1 10 .1 276 .34 10 .1 10 .2 276 .3S 10 .2 10 .2 276.42 10.2 10.3 276.4~ 1 O.< 10 .3 276.46 10 .3 10.3 276.4E 10.3 10.3 276.45 10 .3 10.2 276.4< 10.2 10.2 276.40 10.2 10.2 276 .3E 10 .2 10 .1 276 .32 10 ,1 10.1 276 .21 10.1 10.0 276.21 10.0 9 .9 276 .1E 9 .9 9.9 276 .10 9 .S 9.8 276 .05 9.8 9.7 275 .99 9.i 7 .6 274.46 7.6 7.5 274 .39 7 .5 7.4 274.32 7.4 7 .3 274 .25 7.3 7 .2 274 .19 7., Total (Detained 10.3 27 6.46 10.3 C> ..J ~ w < I- I-!!! ci: 0 >< c ... w 23.6 10.0 cfs cfs 0 .0 0 .0 2.4 2.4 4 .7 4 .7 7.1 7.1 9.4 9.4 11 .8 11 .8 14 .1 14 .1 16 .5 16 .5 18 .8 18 .8 21 .2 21 .2 23.6 23 .6 22.4 22 .4 21 .2 21.2 20 .0 20 .0 18.8 18.8 17 .7 17 .7 16 .5 16.5 15 .3 15 .3 14 .1 14 .1 13.0 13.0 11 .8 11.8 10 .6 10 .6 9.4 9.4 8.2 8 .2 7 .1 7 .1 5.9 5.9 4 .7 4 .7 3.5 3.5 2.4 2.4 1.2 1.2 0.0 0 .0 0.0 0.0 0.0 0 .0 0.0 0 .0 0 .0 0 .0 0.0 0 .0 0.0 0.0 0.0 0.0 0 .0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0.0 0.0 Total (Predeveloped 23 .6 11/3/2005 0533-Dra Exhib it C4 -r. c. ~ Cl e 'ot c:: "' M 0.. 0.. 0.. "O < < < < >-::i: c c c c Qp 17.5 13.9 13 .2 1.5 Tc 11.0 10 .0 10 .0 10 .0 Min inc 1.0 1.0 1.0 1.0 Time cfs cfs cfs I cfs I 0 .0 0 .0 0.0 0.0 0 .0 1.0 1.6 1.4 1.3 0.1 2 .0 3 .2 2 .8 2 .6 0 .3 3.0 4 .8 4 .2 3.9 0.4 4 .0 6.3 5 .6 5.3 0 .6 5.0 7.9 7 .0 6 .6 0.7 6 .0 9 .5 8.4 7 .9 0 .9 7.0 11 .1 9.8 9.2 1.0 8.0 12 .7 11 .2 10.5 1.2 9.0 14 .3 12 .6 11.8 1.3 10.0 15 .9 13.9 13 .2 1.5 11.0 17.5 13.3 12.5 1.4 12.0 16 .7 12.6 11.8 1.3 13 .0 15 .9 11 .9 11.2 1.2 14.0 15 .1 11.2 10.5 1.2 15.0 14 .3 10 .5 9.9 1.1 16.0 13.5 9 .8 9 .2 1.0 17.0 12 .7 9 .1 8.5 0.9 18.0 11.9 8.4 7 .9 0 .9 19 .0 11 .1 7.7 7.2 0.8 20 .0 10 .3 7.0 6 .6 0 .7 21 .0 9.5 6 .3 5.9 0.7 22 .0 8 .7 5 .6 5.3 0 .6 23.0 7.9 4 .9 4.6 0.5 24 .0 7 .1 4 .2 3 .9 0 .4 25 .0 6 .3 3.5 3.3 0.4 26.0 5 .6 2 .8 2 .6 0 .3 27.0 4 .8 2 .1 2.0 0.2 28 .0 4 .0 1.4 1.3 0 .1 29.0 3.2 0 .7 0 .7 0.1 30.0 2.4 0 .0 0 .0 0.0 31.0 1.6 0 .0 0 .0 0.0 32 .0 0 .8 0 .0 0 .0 0.0 33.0 0.0 0 .0 0.0 0.0 34 .0 0 .0 0 .0 0 .0 0 .0 35 .0 0.0 0 .0 0.0 0.0 36 .0 0.0 0 .0 0 .0 0.0 37 .0 0.0 0 .0 0.0 0 .0 60.0 0.0 0 .0 0 .0 0.0 61 .0 0.0 0 .0 0.0 0.0 62 .0 0 .0 0 .0 0.0 0 .0 63 .0 0.0 0 .0 0.0 0.0 64 .0 0 .0 0 .0 0 .0 0.0 PEAK FLOWS 17.5 13.9 13.2 1.5 EXHIBIT C4 Proposed Detention Pond Routing BRENHAM BANK D.A. # Pond Routing EVENT= c c C1 w t. z c iii + C1 :E .:. + :::!; c :E + c 0 ~ ~ t) c cfs I cfs I cfs I cfs 0 .0 4.4 0 .0 0.0 4.4 13.3 1.4 4 .4 8 .9 22.2 5 .0 14 .8 13 .3 31 .1 17 .0 27.2 17 .8 40 .0 36 .9 48.1 22 .2 48.9 64.6 76.9 26 .7 57 .8 99 .7 113.5 31 .1 66 .6 143 .0 157.4 35.5 75 .5 194.5 209.7 40 .0 84.4 254.0 27 0.0 44.4 89.0 321.5 338 .4 44.6 87 .0 392 .9 410 .5 42.4 82 .5 461 .6 479.9 40.1 78 .1 525.3 544 .2 37 .9 73.6 584 .1 603.4 35.7 69 .2 638 .0 657.7 33 .5 64 .7 687 .1 707 .1 31.3 60 .3 731 .5 751.8 29.0 55 .9 771.2 791.8 26 .8 51 .4 806.2 827.0 24.6 47 .0 836 .6 857.6 22.4 42 .5 862.4 883.6 20.2 38 .1 883 .6 904.9 17.9 33 .6 900 .3 921 .7 15.7 29 .2 912.4 933.9 13 .5 24 .8 920.1 941.6 11 .3 20 .3 923.3 944.8 9.0 15.9 922 .0 943.6 6 .8 11.4 916.4 937.9 4 .6 7.0 906.3 927 .8 2.4 4 .0 891 .9 913 .3 1.6 2.4 874 .6 895.9 0 .8 0.8 855 .9 877 .0 0.0 0.0 835.7 856.7 0 .0 0 .0 814.8 835 .7 0.0 0.0 794 .1 814.8 0 .0 0 .0 773 .5 794.1 0.0 0.0 753 .0 773.5 0 .0 0.0 322.6 339 .6 0.0 0.0 305.9 322.6 0 .0 0 .0 289.4 305 .9 0.0 0.0 273 .1 289.4 0 .0 0 .0 257 .0 273 .1 44.6 100 c 0 .. cu ~~ > G> VJ 0 ~ iii 0 ..J 0 0.. u. s "O 0 I-c :I 0 a::::> 0 0.. 0.. 0 I cfs ft cfs 0 .0 272.0( 0 .0 1.5 272.31 1.5 4 .9 273.0C 4 .9 5.1 273 .13 5.1 5 .6 273 .3< 5.6 6.2 273 .63 6.2 6 .9 274 .0C 6 .9 7.2 274 .20 7.< 7 .6 274.4< 7.6 8.0 274 .72 8.( 8 .5 275 .0, 8.~ 8.8 275 .27 8.8 9 .1 275 .51 9.1 9.4 275 .74 9.4 9 .7 275 .9< 9 .7 9.9 276 .10 9 .~ 10 .0 276 .24 10 .( 10.2 276 .36 10.• 10.3 276.4E 10. 10.4 276.57 10 .• 10 .5 276 .6E 10.~ 10.6 276.73 10 .t 10.7 276 .7S 1 O.i 10.7 276 .83 10 .71 10 .7 276.8i 10 .i 10.8 276.89 10 .1 10 .8 276 .9( 10.: 10 .8 276 .90 10 .1 10 .8 276.8! 10.: 10.7 276.85 10 .7 10.7 276 .81 10.i 10 .6 276.76 10 .6 10 .6 276 .71 10 .6 10.5 276.65 10 .5 10.4 276 .60 10.4 10.4 276 .54 10 .4 10.3 276.48 10.3 10 .2 276.42 10 .2 8.5 275 .02 8 .5 8.4 274.95 8.4 8 .3 274 .88 8 .3 8 .1 274.80 8.1 8 .0 274.73 8 .0 Total (Detained 10 .8 276 .90 10.8 (!) ..J ~ w cl: I- I-!Q < e~ c 26 .5 10 .0 cfs cfs 0 .0 0 .0 2.6 2.6 5 .3 5.3 7 .9 7.9 10 .6 10.6 13.2 13 .2 15.9 15 .9 18 .5 18 .5 21.2 21 .2 23 .8 23.8 26 .5 26 .5 25 .1 25 .1 23.8 23.8 22.5 22.5 21.2 21 .2 19 .9 19 .9 18 .5 18 .5 17.2 17 .2 15 .9 15 .9 14 .6 14.6 13.2 13 .2 11.9 11.9 10 .6 10.6 9.3 9.3 7.9 7 .9 6 .6 6 .6 5.3 5.3 4 .0 4.0 2.6 2 .6 1.3 1.3 0.0 0 .0 0.0 0.0 0 .0 0 .0 0.0 0.0 0.0 0.0 0.0 0 .0 0 .0 0 .0 0.0 0.0 0.0 0 .0 0.0 QJ 0 .0 0.0 0.0 0.0 0 .0 0.0 Total (Predevelooed 26.5 11/3/2005 0533-Dra Exhibit C4 Carol Cotter City of College Station Planning & Deve lopme nt Services PO Box 9960 College Station, TX 77840 RE: Brenham Bank Fire Flow Report Dear Carol : MITCHELL M M MORGAN 0'5-US November 28, 2005 CJ:35 ~ Below is the f ireflow analysis for Brenham Bank. The bank development is contained on a 2 .03 lot, requiring a peaked domestic flow of approximately 4 .23 gpm. Domestic flow was calculated using the Norma l Flow method 2 as pre sented in the Revised 2005 B/CS Unified De sign Guidelines . The bank is approximately 3, 700 square feet requiring the minimum fireflow of 2500 gpm as directed in the Revised 2005 B/CS Unified Design Guide line s. Please note that this development requ ires only a 1750 gpm fireflow assu ming no automatic sprinklers and construction w ithout fire retardant materials , per th e 2000 International Fire Code as shown in Exhibit 1. The updated City of College Station water system MikeNET model was checked against a hydra nt flow test near the new Holiday Inn adjacent to the proposed deve lopment. It w as found that model results were similar to those found by flow tests under both static and residual conditions . Please see Exhibit 2 for the hydrant flow test report. Flow Test and MikeNET Comparison Method Static Residual Demand Flow Test 100.0 psi 96 .0 psi 1455 qpm MikeNET 106.6 psi 97 .8 psi 1455 gpm 511 UNIVERSITY DRIVE EAST, SUITE 204 • COLLEGE STATION, TX 77840 • T 979 .260.6963 • F 979 .260.3 564 CIVIL ENGINEERIN G • HYDRAULICS • HYDROLOGY • UTILITIES • STREETS • SITE PLANS • SUBD IVISION S info@mitchellandmorgan .com • www.m1tchellandmorgan.com The peaked domestic flow and a fireflow of 2500 gpm were split between two hydrants; 1004 .23 gpm was placed on the hydrant to be constructed with Brenham Bank (Junction 2223) and 1500 gpm was placed on the existing hydrant near the northwest corner of the Holiday Inn property (Junction 2227). Using the updated City of College Station water system MikeNET model flows and pressures were calculated in the adjacent lines as shown in Exhibit 3. The placement of the existing and proposed fire hydrants is shown in Exhibit 4 . It was found that the six inch (6") waterline line to be constructed with Brenham Ban k will sufficiently serve the water needs of the development. Because velocities remained below 12 fps and pressure remained at or above 20 psi in all scenarios, we believe that a six inch waterl ine will serve the fireflow demands of this development. If you have any comments, or would like to discuss our findings further, please feel free to contact me. Veronica J.B. Mor a Managing Partner cc: f ile S:\P roj\0533-Bren ham _Bank\docs\0 533 -water_a nd _fir e_report -051028.doc ( r ( TABLE 8105.1 MINIMUM REQUIRED ARE FLOW AND FLOW DURATION FOR BUILDINGS (:: PIN!AREA'-t.IO -...... ""-IA end u• ....,_ JV end Y-A. Type ..... 1'YDe V4I' ~22.700 ~12,700 0-8.200 ~S.900 ~3.600 22. 701-30,200 12,701-17.000 8.201-10,900 S,901-7,900 3.fiOl""'.IOO 30.201-38 700 17,001-21,800 lo.901-12.900 7.901-9,800 4',801-6.200 38. 701-4'8,300 21,801 -24,200 12,901-17.4'00 9 801-12.600 6.201-7.700 41._~1-59.000 24.201-33,200 17,401-21.300 12,601-15.«X> 7.701-9.«X> 59.001-10..CJOO ,-3U01-39,700> 21.301-lS.SOO lS,401-18.AOO 9,401-11,300 10..001-13.700 39.701 .... 7,100 25-501-30..100 18 401 •21.loo ll~l-13,400 l!..101-97.100 "7.101-SUOO (oift "" -'l<C .m:' 21.101-25.900 13.AOl-15,600 \ 97.101-112. "JOO 54.001-63.«X> ~.101..eo.fiOO ............ ~ ..... H.Ml-ll.000 112.701-171700 63.'401-72,G 40,601..46.400 29-.i_MI_ [IJllJl-:ID.&IO ltt.701-145-'00 72.401-12, 100 ~401-52,SOO . 33.!Ql-rttoo 20.601-23.'.)Q() 145 Gnl-164 ""' H..101~4'00 ~l-59.100 37.IOl.Q.700 23.301-26.300 164.201-183.400 92,401-103,100 '9.101-66.000 <42,701-47,700 26.3()1.:29,300 183.401-203. "700 103.101-11-4,600 66,001-73,300 "7.701-53.000 29.301-32,600 203 701-225.200 114..fiOl-126.700 73.lOl-11.100 53JJ01-5UOO ntiAl-~ 225.201-2A7.700 l'l&. 701-139,400 81 101-19.200 g.fiOl~_Mm 36.001-39,600 24'7~'101-271.200 139.401-152,600 89.201-97,700 65.AOl-10..fOO !9.liOl .... 3.«X> 271.201-295.900 152,601-166,SOO 97.701-106.500 70.601-71 000 43.401""'7.«X> 295 901..n...-1~1-0laler 1~1-115.IDO 71 JIDl .a. 700 "7.AOl-51.500 --115.IOl-125..D> 11:101..-.0 51.:501-55,1'0 --12S.S01-13S.SOO 9UOl.f7.lm . 55.701~ --13S.S01-14S,IOO 97..tOl-lllUDO QtMJ-6&..lllD ~ --1<45.801-156,700 106.l01-113..DJ 64.IOl-69.• --156.701-167,900 l 13.201-12UOO 69..f01-7UOO --167.001-179.«X> 121.301-12'.MIO 7'-Ml-l't..., --179.AOl-191,4'00 129.601-131..lOO 79.IOl-15~1• --191,401-<mater 138.301-0reller as.101.0.... For SI: I ~foot• 0.0929.11'2, I plloa per lllimde • 3.ru Um. I pound per lqlllN inch• 6.19S kPa. L Types of c:OMCnlction are based oa lhe '""""""""" B11iltlit1K Cod~. b. Meuured • 20 psi. AREA.OW PLOW , ................. ,. DURATION,.__, 1.SOO l,750 2,000 2 2..2.SO 2,SOO '. 2,750 3.000 3.2SO. 3 3.SOO 3.750 . 4'.000 4'.2SO -4.SOO 4',150 5.000 S.lSO f s.soo S,150 6.000 " I ~.,v. ) ...___.. 6,500 6.750 1Jm 1.2SO 7.D> 7,7"50 1.000 .. ·------·-·--···---~ .. --·---·· .. •···· -· ( t .. 2000 INTERNATIC EXHIBIT 1 College Station Utilities Reliab le, Afforda ble, Community Owned 1601 GRAHAM ROAD COLLEGE STATION TEXAS 77845 Date: 31OCTOBER2005 Phone: 979-764-3435 FLOW TEST REPORT Nozzle size: 2.5 inch Location: 2500 EARL RUDDER Flo w hydrant number: F-107 Pitot reading: 75 (GPM): 1455 Static hydrant number : F-109 Static PSI: 100 Residual PSI: 96 EXHIBIT 2 Brenham Bank Firetlow Analysis Steady State condition s, fireflow s pli t between new B re nh am Ban k fire hydrant Uunc ti o n 2223) and existing hydrant at j un ctio n 2227 \ \ 122 . /'·~"'~ // .> / ' // ._,<:0 \, .2222 / 'l,b°" /. / ~23)., / . (' \ / / \ ~ / / \\., / / / / ' \ / / \ .2~25 \ / / \\ ~ \( / /,\f231 .\ ,// r&~/ .;~ , / \ G \ / \ dl \ // 202'5 • \ \\ // 'iro'i /-~,, \ .2232 \ / ":> .~28 \ \/ 'l,~'l,'J/ ')\ \ '/i.21 / \ \ \ . / "\ ' '\ \ \ / \~ / '\ / \\ / \\ / "\ \ / /' \ \ \ // / ~ \ / '\ / . '\\ \ / \ ,../ Ho r izontal Plan EXHIBIT 3 Results -Junctions Number of Junctions: 15(Selectio n) 1 Junction ID Description Elevation Demand Grade Pressure I [ft] [gpm] [ft] [psi] I 213 J-8030 287.000 0.188 498 .254 91.536 I 214 J-8020 287.000 1.034 500 .095 92.334 I 636 J-1890 287.000 1.129 501.365 92.884 I 122 J-330 286.000 5.154 500.378 92.890 I 2222 280.000 0.000 498 .913 94.855 2223 279.000 1004 .000 494.500 93.376 2224 283.000 0 .000 499.827 93 .951 2225 277.000 0 .000 498.896 96.147 2226 284 .000 50.000 495.376 91.589 2227 282.750 1500.000 494.198 91.620 2228 282.000 0.000 495.033 92.307 2229 281.000 0 .000 495 .708 93.033 I 2230 280.0 00 0 .000 497.279 94 .147 I 2231 275.500 0 .000 498.891 96 .796 I 2232 274.750 0 .000 499 .028 97 .180 EXHIBIT 3 Results -Pipes Number of Pipes : 15(Selection) I Pipe ID Description Node 1 Node2 Diameter Length Roughness Flow Velocity Headloss I [in] [ft] [ millift] [gpm] [ ft/s] [ft] I 1226 P-8090 214 213 8.000 104 .093 11 0.000 742.448 4.739 1.841 I 1227 P-8080 636 214 8.000 63 .269 110.000 746.665 4.766 1.269 I I 1593 P-1740 722 636 12 .000 750.771 120 .000 -629.732 -1.786 0.987 I 2617 P-260 2222 2224 12.000 230 .90 I 120 .000 -1145.899 -3.251 0 .914 I 2618 2222 2223 6.000 67.735 140.000 1004.000 11.393 4.412 I 2619 P-260 2224 722 12 .000 134.800 120.000 -1 145 .899 -3.251 0.551 I 2620 P-260 2225 2222 12.000 207 .043 120 .000 -141.899 -0.403 0 .017 I 2621 213 2226 8 .000 3 13 .953 140 .000 742.260 4.738 2.879 I 2622 2226 2227 8.000 146 .204 140.000 692.260 4.419 1.178 I 2623 2227 2228 8.000 77 .9 12 140 .000 -807.740 -5 .156 0.835 2624 2228 2229 8.000 62 .9 11 140.000 -807.740 -5.156 0.675 2625 2229 2230 8.000 146.574 140 .000 -807.740 -5 .156 1.572 2626 P-260 2231 2225 12 .000 47.7 18 120 .000 -14 1.899 -0.403 0 .004 2627 2230 223 1 8.000 150.346 140.000 -807.740 -5 .156 1.6 12 I 2628 P-260 2232 2231 12.000 96 .572 120 .000 665.841 1.889 0.137 EXHIBIT 3 \ ~ "' (]._ I- (/) w ;;: I I-=> 0 (/) ::, \ i, \ r \ S H6 -------PROPOSEDHYDRANT __ _ (MIKENET JUNCTION 2223) ---12-WL--~-----12-WL ~------1; /!-r-------;,r--r.~~---~~~mm:============fGTSE =!==-=t===;;=~GTE~=-=-~~:J'.:'-=--" -r-f='-----OE- / ·1.s.:wi_ - - - ------ - - -1 I I JJ ff=; 11. " " I • · · 1 I i ?;:·nm ~ : . l 11# I ~. . . . . . . . . . . /·/l l.FT\L-, ____,.,,...,,... § ~ ~ .· . // . ~ ... :; :.: .. :: ·,:.: ...... · ......... ...:.. .. ~ ·_· ~;~, "~. f; I /I 11 \ ~ EXISTING HYDRANT ~ (MIKENE T JUNCTION 2~?,_?.J-.---,..,. \~ ---~ \)( ....... ~,... ~ :.----_., ....... ___. --~ ---~ --------\ ------~ ---------~ -----~ Yr-==--~ \ ------~ ~· ~~ ------ch = 8 0 feet ------_:::::=--: ------------~ FIRE HYDRANT PROXIMITY Mi tc hell & Morg an , L.L.P . • Revis ions Consulting Engineers end Co nstructors November, 2005 BRENHAM BANK 511 University Drive East, Suite 204 Designed by: VJB M ~~ College Station , TX 77840 Drown By· RAR (979) 260-6963 Fo .: (979) 260-3564 Checked By. VJB M .. Ii ·-Notice of Intent (NOi) for Storm Water TCEQ Office Use Only r • Discharges Associated with Construction =' '!I TPDES Permit Number: TXR15l _l_l_l_I • Activity under the TPDES General Permit GIN Number: 1-1-1-1-1-1-1-1 Fee Receipt No . TCEQ IMPORTANT: •Use the attached INSTRUCTIONS when completing this form. •After completing this form, use the attached CUSTOMER CHECKLIST to make certain all items are complete and accurate. •Missing, illegible, or inaccurate items may delay final acknowledgment or coverage under the general permit. Application Fee: You must submit the $100 NOi Application Fee to TCEQ under separate cover (see instructions) using the attached Application Fee submittal form . (DO NOT SEND A COPY OF THE NOi WITH THE APPLICATION FEE SUBMITTAL FORM) Tell us how you paid for this fee: Check/Money Order No.: Name Printed on Check: A. OPERATOR 1. TCEQ Issued Customer Number (CN) (if available): 2 . Legal Name (spelled exactly as filed with the Texas Secretary of State, County, or legal document that was used in forming the entity): The Brenham National Bank 3 . Mailing Address: P .O . Box 2568 Suite No./Bldg.No.: City: Brenham State: Texas I ZIP Code: 77834 4 . Phone No.: ( 979 ) 277 -6171 Extension: 5. FAX No. (979) 836-1408 E-mail Address: dborchardt@bnbank .com 6 . Type of Operator: C Individual Cl Sole Proprietorship-D.B.A. Cl Partnership [!J Corporation CJ Federal Government CJ State Government CJ County Government C City Government CJ Other: 7. Independent Operator: EJYes Cl No (If governmental entity or a subsidiary or part of a larger corporation, check "NO") 8 . NumberofEmployees: C10-20; GJ21-100; CJ 101-250; CJ 251-500; or CJ 501 or higher 9 . Business Tax and Filing Numbers (not applicable to Individuals, Govemmen~ General Partnerships, and Sole Proprietorship-D.BA): State Franchise Tax ID Number: 17 405251558 Federal Tax ID: 74-0525155 TX SOS Charter (filing) Number: 0001367802 DUNS Number: (If known) B. BILLING ADDRESS (The Operator is responsible for paying the annual fee.) 0 Same As Operator (check if address is the same, then proceed with Section C .) 1. Billing Mailing Address: P .O . Box 2567 Suite No./Bldg .No.: City: Brenham State: Texas I ZIPCode: 77834 2 . Billing Contact (Attn or C /O): Douglas R. Borchardt 3. Country Mailing Information (if outside USA) Territory: Country Code: Postal Code: 4 . Phone No.: ( 979 ) 277-6171 Extension: 5. FAXNo. (979) 836-1408 E-mail Address: dborchardt@bnbank.com TCEQ-20022 (07/12/2004) Page I of3 ' . C. APPLICATION CONTACT (lfTCEQ needs additional information regarding this application, who should be contacted? 1. Name: Douglas R. Borchardt Title: Vice President Company: Brenham National Bank 2 . Phone No.: ( 979 ) 277 -6171 Extension: 3 . FAXNo. (979) 836-1408 E-mail Address: dborchardt@bnbank.oom D. REGULATED ENTITY (RE) INFORMATION ON PROJECT OR SITE I. TCEQ Issued RE Reference Number (RN) (if available): 2 . Name of Project or Site: Brenham National Bank 3 . Physical Address of Project or Site: (enter in spaces below) StreetNumber: 2470 Street Name: Ear1 Rudder Freeway City (nearest to the site): ZIP Code (nearest to the site): County (Counties if >l): College Station 77840 Brazos County 4. If no physical address (Street Number & Street Name), provide a written location access description that can be used for locating the site: (Ex.: 2 miles west from intersection of Hwy 290 & IH35 on Hwy 290 South) 5. Latitude: 30 .619 N Longitude: 96 .297 w 6 . Standard Industrial Classification (SIC) code: 6021 7 . Describe the activity related to the need for this authorization at this site (do not repeal the SIC and NA/CS code): National Commercial Bank 8 . ls the project/site located on Indian Country Lands? 0Yes IEJNo IfYes, you must obtain authorization through EPA, Region VI . E. SITE MAILING ADDRESS (address for receiving mail at the site) 0 Same As Operator (check if address is the same, then proceed with Section F .) Mailing Address: Suite No./Bldg.No.: City: State: ZIP Code: F. GENERAL CHARACTERISTICS 1. Has a Pollution Prevention Plan been prepared as required in the general permit? IEJYes CJ No If No, coverage may be denied as the PPP is required at the time the NOi is submitted to TCEQ. 2 . Provide the estimated area of land disturbed (to the nearest acre): 1 Acres 3 . Provide the name of the receiving water body (local stream, lake, drainage ditch), MS4 Operator (if applicable) and the segment number where storm water runoff will flow from the construction site. MS4 Operator: City of College Station Receiving Water Body: Wolf Pen Creek Segment TCEQ-20022 (07/12/2004) Page 2 of3 , .. G. CERTIFICATION L Douglas R. Borchardt Executive Vice President Typed or printed name Title (R.equire~ certify under penalty oflaw that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directl y responsible for gathering the information, the information submitted is, to the best of my knowledge and belief; true, accurate, and complete. I am aware there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. I further certify that I am authorized under 30 Texas Administrative Code §305 .44 to sign and submit this document, and can provide documentation in proof of such authorization upon request. Signature : ________________ _ Date: _____________ _ (Use Blue Ink} TCEQ-20022 (07/12/2004) Page 3 of3