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Home My WebLink AboutFolderFOR OFF CASE NO.: -~-'-.-.~~A-,--t-r-- CITY OF C OLLEGE STATIO l Home of Texas A&M Univmiry• DEVELOPMENT PERMI T APPLICATION MINIMUM SUBMITTAL REQUIREMENTS: £soo (minimum) Development Permit Application I Public Infrastructure Review and Inspection Fee. Fee is 1 % of acceptable Engineer's Estimate for public infrastructure, $600 minimum (if fee is > $600, the balance is due prior to the issuance of any plans or development permit). ~Two (2) copies of the grading, drainage, and erosion control plans with supporting drainage report. -B-Two (2) copies of the Public infrastructure plans and supporting documents (if applicable). Date of Optional Preapplication or Stormwater Management Conference SPECIAL FLOOD HAZARD AREA? D Yes ~No NAME OF PROJECT ADDRESS 06 --~~~-----4-'-'~~-+-"-------~---~--~~-------- 3 Lof-I 1- -~P,.~ ___ Zip Code /7 f34S- Phone Number q? 1 . (o9tJ · ~ B2S Name /OD. E-mail Street Address City U State ____ 7X<=--~--Zip Code Phone_N_u_m-be_r __ -_-_-_~9~7~~q~_~.~~:5~~'l::J~-~~q~2~~Z-'-Lj_,___ Fax Number NDt/€. ARCHITECT OR EN~EER'S INFORMATION: Name JM_ {Z_a::tL,J , /1€ E-man d~~~<V1f!rJ~.lh'1}-{, StreetAddress Z.0/0 MoJ€S ~ tf --=Q._g"-=-----------State -~1>Z._~---Zip Code J 7 8i/S-City Phone Number __ q_71 __ .~5_rz~s_. ~!)i_D_'Z.._'2._ ____ Fax Number 17~, {d/0 · loB ~~ 10/10 Page 1 of 4 ./• " CERTIFICATIONS REQUIRED FOR ALL DEVELOPMENT Owner Certification: 1. No work of any kind may start until a permit is issued. 2. The permit may be revoked if any false statements are made herein. 3. If revoked, all work must cease until permit is re-issued . 4. Development shall not be used or occupied until a Certificate of Occupancy is issued. 5. The permit will expire if no significant work is progressing within 24 months of issuance. 6. Other permits may be required to fulfill local, state, and federal requirements. Owner will obtain or show compliance with all necessary State and Federal Permits prior to construction including NOi and SWPPP. 7. If required , Elevation Certificates will be provided with elevations certified during construction (forms at slab pre- pour) and post construction. 8. Owner hereby gives consent to City representatives to make reasonable inspections required to verify compliance. 9. If, stormwater mitigation is required, including detention ponds proposed as part of this project, it sha ll be designed and constructed first in the construction sequence of the project. 10. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that all debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply. 11. The information and concl_usions contained in the attached plans and supporting documents will comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines Technical Specifications, and Standard Details. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 12. Release of plans to (name or firm) is authorized for bidding purposes only. I understand that final approval and release of plans and development for construction is contingent on contractor signature on approved Development Permit. 13. I, THE OWNER, AGREE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR :~~~~:r~OPMENT PJ;ERMIT APPLICATION, ARE, TO THE BEST OF MY KNO/WLEDGE, TRUE, AND W.JL ;;:_____ 10/11 LZo11 Property Owner(s) Date I f Engineer Certification: 10/10 1. The project has been designed to ensure that stormwater mitigation, including detention ponds, proposed as part of the project will be constructed first in the construction sequence. 2. I will obtain or can show compliance with all necessary Local, State and Federal Permits prior to construction including NOi and SWPPP. Design will not preclude compliance with TPDES: i.e., Project over 1 O acres may require a sedimentation basin. 3. The information and conclusions contained in the attached plans and supporting documents comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and associated BCS Unified Design Guidelines. All development has been designed in accordance with all applicable codes and ordinances of the City of College Station and State and Federal Regulations. 4. I, THE ENGi ER, AG EE TO AND CERTIFY THAT ALL STATEMENTS HEREIN, AND IN ATTACHMENTS FOR THE D ELO NT PERMIT APPLICATION, ARE, TO THE BEST OF MY K OWLEDGE, TRUE, AND ACCURAT~~-.,il.-4~t-/f-=-~-- Date Page 2 of 4 The following CERTIFICATIONS apply to development in Special Flood Hazard Areas. Required for Site Plans, Final Plats, Construction Plans, Fill /Grading Permits, and Cleari ng Only Permits:* A. I, certify, as demonstrated in the attac drainage study, that the alterations or development covered by this permit, shall not : (i) increase the Base Flood elevation; (ii) create additional areas of Special Flood Hazard Area; (iii) decrease the conveyance capacity to that part of the S cial Flood Hazard Area that is not in the floodway and where the velocity of flow in the Base Flood ev is greater than one foot per second . This area can also be approximated to be either areas within feet of the boundary of the regu latory floodway or areas where the depth of from the BFE to n ral ground is 18 inches or greater; (iv) reduce the Base Flood water storage ume to the part of the Special Flood Hazard Area that is beyond (v) the floodway and conveyance are here the velocity of flow in the Base Flood is equal to and less than one foot per second without ac ptable compensation as set forth in the City of College Station Code of Ordinances, Chapter 13 co erning encroachment into the Special Flood Hazard Area; nor xempted by ordinance in Section 5.11.3a of Chapter 13 Code of Ordinances. Date Initial D * If a platting-status exemption to this requirement is asserted, provide written justification der separate letter in lieu of certification. Required for Site Plans, Final Plats, Construction Plans, and Fill / Gradin B. I, (i) that any nonresidential or multi-family stru cture on or proposed e on this site as part of this application is designed to prevent damage to the structure or its co ntents a result of flooding from the 100-year storm. Engineer Date Additional certification for Floodwa C. I, ----------~------' certify that the construction, improvement, or fill covered by this e flood elevation. I will apply for a variance to the Zoning Board of Adjustments. Engineer Date 10/10 Page 3 of4 , Required for all projects proposing structures in Special Flood Hazard Area (Elevation Certificate required). Residential Structures: D. I, , certify that all new construction or y substantial improvement of any residential structure shall have the lowest floor, including all utilities, ductw and any basement, at an elevation at least one foot above the Base Flood Elevation. Required Elevation ertificates will be provided with elevations certified during construction (forms at slab pre-pour) and post co ruction. Engineer I Surveyor Commercial Structures: E. I, , ce · that all new construction or any substantial improvement of any commercial, industrial, or other non-residen ·al structure are designed to have the lowest floor, including all utilities, ductwork and basements, elevated at le st one foot above the Base Flood Elevation Engineer I Surveyor Date OR I, , certify that the structure with its attendant utility, ductwork, basement and sanitary facili es is designed to be flood-proofed so that the structure and utilities, ductwork, basement and sanitary fa · 1ties are designed to be watertight and impermeable to the intrusion of water in all areas below the Base Fl od Elevation, and shall resist the structural loads and buoyancy effects from the hydrostatic and hydrod namic conditions. Required Elevation ertificates will be provided with elevations certified during construction (forms at slab pre- pour) and post co struction. Engineer I Surveyor Date Conditions or comments as part of approval: Print Form 10/10 Page 4 of 4 Erika Bridges From: Erika Bridges Sent: To: Friday, August 03, 2012 4:24 PM 'Joe Gattis' Cc: Subject: 'william@scarmardo.com'; Alan Gibbs RE: Record Drawings -Circuit City Joe, The letters look fine. I wasn't sure if Bill was the owner or not since 1003 Harvey Rd., LLD is listed on the application and BCAD as the owner. Do you know if he is the owner? Please forward this email as an FYI to the owner (if it is someone other than Bill). We would like them to be aware that the detention pond, as with all ponds in the City, is subject to routine inspections periodically to make sure it is functioning properly. There were some specific issues identified and acknowledged with this pond, so hopefully the agreed upon maintenance will prevent any drainage problems. If not, future improvements to the pond may be requested. Please let us know if you have any questions. Thanks, Erika Erika Bridges, EIT, CFM Graduate Civil Engineer Planning & Development Services 1101 Texas Avenue, College Station, TX 77842 (979) 764-3570 City of College Station Home of Texas A&M University ® From: Joe Gattis [mailto:joe@gattisengineering.com] Sent: Friday, August 03, 2012 2:48 PM To: Erika Bridges Subject: FW: Record Drawings -Circuit City Importance: High Hello Erika. In response to your email below, I have attached a letter from William Scarmardo addressing issues that you listed below and a letter from me addressing the pond performance. You already have the Record Drawings in hand. Please let me know if you need anything else. The City is withholding the C.O. from Guitar City and their Grand Opening is next week. We have to resolve immediately. Thanks in advance, 1 JoeG Joe Gattis, PE Gattis Engineering (979) 575-5022 (979) 690-6888 fax From: Erika Bridges [mailto:ebridges@cstx.gov] Sent: Wednesday, July 11, 2012 5:31 PM To: 'Joe Gattis' Subject: RE: Record Drawings -Circuit City Joe, I noticed a few minor issues besides the flume missing, but they are not critical. Since this is a privately maintained pond, these items should be addressed to keep the pond functioning properly: • The rip rap was not installed flush with the existing pavement and seems to be preventing some water from entering the pond. • It looks like fill and grass are blocking water from entering the pond at the bottom of the rip rap . • There appear to be several low spots in the pond that are holding water. • The existing concrete channel next to the apartments has debris which is causing water to pond . • FYI... If the flume is not constructed, the owner should be aware that the pond will probably hold water longer and may be more difficult to maintain. The bottom line is that the pond was not built as shown in the approved plans. With the certification on the as-builts, you are attesting that the pond was built "in accordance with the approved construction plans or amendments thereto approved by the City of College Station." In this case, the certification seems to be inaccurate since the pond was not built to plans and isn't meeting all the B/CS Unified Stormwater Design Guidelines. We have 2 conditions to accept the record drawings provided and not hold CO: 1. Submit a revised Letter of Acknowledgement specifying design items not meeting our standards. 2. Provide a letter or email confirming that you have observed the pond post-construction. Additionally, verify that the pond has adequate volume and should function as designed. Please let me know if you have any questions. Thanks, Erika Erika Bridges, EIT, CFM Graduate Civil Engineer Planning & Development Services 1101 Texas Avenue, College Station, TX 77842 (979) 764-3570 2 City of College Station Home of Texas A&M University ® From: Joe Gattis [mailto:joe@gattisengineering.com] Sent: Monday, July 09, 2012 3: 11 PM To: Erika Bridges Subject: RE: Record Drawings -Circuit City They did not build the pilot channel. They did not ask my permission for leaving it out. I visited with contractor during construction and he confirmed top of grate elevation and top of curb elevations and confirmed that they matched my plans and therefore his grading would too. The new berm itself looks to be a little higher but that is not a problem. The pilot channel that was not installed really should not be a problem with the pond being so small, so I did not make a big deal out of it not being installed. It performed as intended during storm events that occurred over the last couple of months as well. I do not have a post-construction survey. Is there something you see as not being correct or a concern? Joe Gattis, PE Gattis Engineering (979) 575-5022 (979) 690-6888 fax From: Erika Bridges [mailto:ebridges@cstx.gov] Sent: Monday, July 09, 2012 3:04 PM To: 'Joe Gattis' Subject: RE: Record Drawings -Circuit City Joe, I did receive the as-builts, but I haven't had a chance to visit the site yet and compare them. Why wasn't the pilot channel installed? It doesn't look like they built the pond as approved. Did you any survey data from the pond to verify elevations? Thanks, Erika From: Joe Gattis [mailto:joe@gattisengineering.com] Sent: Monday, July 09, 2012 2:45 PM To: Erika Bridges Subject: Record Drawings -Circuit City 3 Have you received the record drawings for Circuit City you requested yet? I mailed them before the 4th of July holiday. JoeG Joe Gattis, PE GATTIS ENGINEERING, LLC 2010 Moses Creek Ct. College Station, TX 77845 979.575.5022 office 979.690.6888 fax joe@gattisengineering.com CONFIDENTIALITY NOTICE: The information contained in this transmission is considered by the sender to be confidential. This material is intended only for use of the recipient named above. If the reader or other recipient ohhis material is not the intended recipient named above, please notify me and delete this transmission. Thank you. "It is understood and agreed, that Gattis Engineering, LLC, upon release of these electronic files is no longer responsible for their use or modification. The user of the attached electronic media accepts full responsibility and liability for any consequences arising out of the use of this electronic data." City of College Station Home of Texas A&M University ® City of College Station Home of Texas A&M University® 4 j;AT ISENGINEERIN~ ENGINEERS -$-CONSULTANTS August 3, 2012 Erika Bridges, EIT Development Services College Station, Texas 77845 Re: Circuit City Detention Pond Rehabilitation Dear Mrs . Bridges, Per your request, I have coordinated with the owner of the Circuit City site William Scannardo. He is aware that the changes that you referenced in your email from July 11, 2012, that he made during construction that differed from the approved construction plans. He understands that these changes that he made for aesthetic reasons might cause him additional maintenance issues in the future. As stated in the attached letter from William Scarmardo, he is willing to accept these possible maintenance issues, has hired a landscape company to handle them and will handle any situations that occur personally. From an engineering and hydraulic performance perspective, it is my opinion that these changes will not have any adverse affect on the detention ponds ability to capture, detain, and meter release storm water as initially designed. FIRM# 7698 • 2010 Moses Creek Ct. • College Station, Texas 77845 • Tel. 979.575.5022 · ·~ 'i;o5 ti~' l). ".'),• ~" 8/2/2012 Erika Bridges City of College Station Development Services Dear:Erlka, I am aware that the changes to the detention pond will create additional maintenance issues in the futu~ and will contract with the landscaping company to ensure the aesthetics and function of the dralhage pond remain. I am further aware of the following specific impllcatlons caused by changes made: :!) We used Rip-Rap River rock in lieu of the concrete flumes shown on the plans. 2) The grass in the detention pond Is below the riprap flow line and will be mowed low and thoroughly. 3) The Concrete Flumes that were on the plans for low energy water flow were left out at owner's choice for aesthetic reasons -and might cause for standing water and low spots and maintenance issues. 4} Siltation, vegetative growth and debris In the existing flume is a maintenance issue We are aware and prepared for standing water if there are low spots in the detention pond, and will include the additional malmenance required as part of our regular grounds keeping. William Scarmardo Joe Gattis From: Erika Bridges [ebridges@cstx.gov] Sent: Wednesday, May 16, 2012 10:21 AM To: joe@gattisengineering.com Subject: Old Circuit City Detention Pond Joe, Page 1 of 1 It looks like they are just about wrapped up on the construction of the detention pond. As a reminder, we need two copies of the record drawings with the Engineer's Certification. Please see the attached sheets from the Unified Stormwater Design Guidelines with the specific language for the certification. Please let me know if you have any questions. Thanks, Erika Bri dges, EIT, CFM Graduate Civi l Engineer Planning & Development Services 1101 Texas Avenue, College Station, TX 77842 (979) 764-3570 City of College Station Home of Texas A&M University ® City of College Station Home of Texas A&M University ® 6/27/201 2 DEVELOPMENT PERMIT PERMIT NO. 11-08 CITY OJ' COLLEGE S"I:·\rlON />l41111i11]!. ,_4 Dt1"t"!opnr11t .Vrvicn FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: Timber Ridge Ph.3, Lots 1-3 Circuit City Detention Pond Redevelop. DATE OF ISSUE: 12/28/11 OWNER: 1003 Harvey Rd., LLC (c/o Joe Gattis) 1003 Harvey Rd . College Station, TX 77840 SITE ADDRESS: 1003 Harvey Rd. DRAINAGE BASIN: Wolf Pen Creek VALID FOR 24 MONTHS CONTRACTOR: TYPE OF DEVELOPMENT: Full Development Permit CONDITIONS: 1. No work of any kind may start until a Development Permit is issued . 2. No work beyond limits covered in permit is authorized. 3. The permit may be revoked if any false statements are made herein. If revoked, all work must cease until permit is re- issued. 4. Development shall not be used or occupied until Certificate of Occupancy is issued. 5. The permit will expire if no significant work is progressing within 24 months of issuance. 6. If required, Elevation Certificates will be provided with elevations certified during construction (forms at slab pre-pour) and post construction. 7. Other permits may have been required to fulfill local, state and federal requirements. Construction will be in compliance with all necessary State and Federal Permits. 8. Stormwater mitigation, including detention ponds will be constructed first in the construction sequence of the project. 9. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that all debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. Construction Site Notice or Notice of Intent (NOi) along with Stormwater Pollution Prevention Plan (SWP3) will be kept and maintained on-site during construction as per TPDES permitting requirements. If it is determined that the prescribed erosion control measures are ineffective to retain all sediment on-site, it is the Contractor's responsibility to implement measures that will meet City, State, and Federal requirements. 10. All disturbed areas will be re-vegetated prior to Letter of Completion or Certificate of Occupancy. 11 . All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with the Landscaping and Tree Protection Section 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. 12. All construction shall be in accordance with the stamped approved plans and specifications for the above-named project and all of the codes and ordinances of the City of College Station, as well as State and Federal Regulations that apply. Only those deviations from BCS Unified Design Guidelines, Specifications and Details specifically requested and approved will be allowed. 13. Special Conditions: *** TCEQ PH .II RULES IN EFFECT*** l, __ {'l\_"'"~""'{_~....._~_D_~_,-'-\'---'..___ _____ , the Contractor, hereby agree to comply with all conditions herein. I J \______.______ I -'\-I ~ Contrbor Date I hereby grant this permit for development. Contact ---li"-IAAJ.--L..1-"'ll!;ci....:;;;)14~--..L-'--""--""=~-· the Public Works Inspector assigned to this project 24 hours prior to beginni n for scheduling required Inspections. ~5A · City Engine~ntative 12/2'&/11 Date Erika Bridges -Re: Circuit City From: To: Date: Subject: You got it! Erika Bridges joe@gattisengineering.com 12/14/2011 4:45 PM Re: Circuit City >>>"Joe Gattis, PE" <joe@gattisengineering.com> 12/14/2011 4:01 PM >>> Please put everything up-front for me to pick up please. Joe Gattis, PE Gattis Engineering, LLC 979-575-5022 From: "Erika Bridges" <Ebridges@cstx.gov> Date: Wed, 14 Dec 201115:45:11 -0600 To: <joe@gattisengineeri ng.com> Subject: Re: Circuit City Joe, Jave a few little comments for you: I need you to put your seal on the new Engineer's Certification. Page 1 of 2 j The plan sheet is showing 2-8' curb openings and the report calls for 3-6' openings. Not sure which one you meant for it to be, but we would like the curb openings to be limited to 4' wide. We are concerned that anything larger wil l lead to cars potentially driving into the pond. 3. On Page 3 of the report it mentions the going from 70'x125' to 70'x79'. When I scale it off the plan sheet it looks more like 65'x70' and 65'x50'. Maybe I'm measuring it wrong, but it looks like it's close to a 50% reduction in size. Where were you taking your measurements? I think these are pretty minor, but let me know if you have any more questions. Thanks, Erika Erika Bridges, EIT, CFM Graduate Civil Engineer Department of Public W orks 1101 Texas Ave. College Station, TX 77842 Phone: 979.764.3570 Fax: 979.764.3496 ebridges@cstx.gov ******************** file://C:\Documents and Settings\ebridges\Local Settings\ Temp\XPgrpwise\4EE8D296City oflQ.:Wtg@lS1 City of College Station Home of Texas A&M University ® >>>"Joe Gattis, PE" <joe@gattisengineering.com> 12/13/20111:57 PM >>> Just checking in Joe Gattis, PE Gattis Engineering, LLC 979-575-5022 Page 2 of2 file://C:\Documents and Settings\ebridges\Local Settings\ Temp\XPgrpwise\4EE8D296City o:tl COOJUgt}N1 ENGINEERING COMMENTS NO. 1 ase submit a Letter of AckJwledgment and Appendix D. . Engineer's Certification does not appear to be complete. Please revise. ~ -W'le Certrf1c@1 ~ post-development drainage areas need to include the detention pond area. Add lJ . 2'2!5Ac ough approximately 1 acre of site runoff does not currently enter the detention pond due to erosion over time, the entire site still needs to be included in the pond sizing , as it / was in the original Circuit City drainage report. Please revise hydrographs and calculations accordingly. Please submit 24x36 copies of the revised drainage and grading plan for review. In addition, this sheet needs to show/label: a. The existing pond b. Pond side/bottom/low-flow invert slopes c. A detail of the outlet structure d. The swale/curb cut allowing water to enter the pond e. The emergency overflow path f. Required erosion control measures (temporary & permanent) g. The 100-yr WSE h. The pond size (Ac-ft) Please provide the following calculations: a. Swale/curb cut sizing for water entering pond b. Pond outlet/weir sizing c. Pond storage routing analysis Reviewed by: Erika Bridges Date: 11/14/11 ~ ~.epcrt Cp. 4) QaJl\3 .flor ~ -,, Qw"\? o~i~-=>. f1w1 ~v05 z-8'. AdL w~\ ~ ~ 1-o tQlf {!J.Aj fuM dnv1"5 ln1"D (bnd? ~L .€1()-st b, F'f· fMds klol0 w°1 dA~-t-> Ii l'.,t ~°"' is \Jei~ ~ ~ ~f. IO 'x-itJ''I' ,_,/ l.©lilC:> \1ll€, lh'xlO "~ovi ~ .e.Al1:i 2'1 !pCJ ;t. 'b6' ovi -&YIW-t .wd (fMj--3) GATTIS ENGINEERING ENGINEERS • CONSULTANTS November 15, 2011 City of College Station -Development Services 1101 Texas Avenue, South College Station, Texas 77845 Re: Letter Acknowledging City Standards -Circuit City Store Detention Pond Re-Development To Whom It May Concern, The purpose of this letter is to acknowledge that the construction plans for the water, sanitary sewer, streets and drainage for the above referenced project, to the best of my knowledge, do not deviate from the B/CS Design Guideline Manual. Any alternate design or construction methodology that was used is listed below: None. I also acknowledge, to the best of my knowledge that the details provided in the construction plans are in accordance with the Bryan/College Station Standard Details . . Gattis, PE ic nsed Professional Engineer $ FmM # F-7698 • 2010 Moses Creek Ct. • College Station, Texas 77845 • Tel. 979.575.5022 • Fax 979.690.6888 $ ENGINEERING COMMENTS NO. 1 1. Please submit a Letter of Acknowledgment and Appendix D. 2. The Engineer's Certification does not appear to be complete. Please revise. 3. The post-development drainage areas need to include the detention pond area. 4. Although approximately 1 acre of site runoff does not currently enter the detention pond due to erosion over time, the entire site still needs to be included in the pond sizing, as it was in the original Circuit City drainage report. Please revise hydrographs and calculations accordingly. 5. Please submit 24x36 copies of the revised drainage and grading plan for review. In addition, this sheet needs to show/label: a. The existing pond b. Pond side/bottom/low-flow invert slopes c. A detail of the outlet structure d. The swale/curb cut allowing water to enter the pond e. The emergency overflow path f. Required erosion control measures (temporary & permanent) g. The 100-yr WSE h. The pond size (Ac-ft) 6. Please provide the following calculations : a. Swale/curb cut sizing for water entering pond b. Pond outleUweir sizing c. Pond storage routing analysis Reviewed by: Erika Bridges Date: 11/14/11 f' . t j;ATTIS ENGINEERIN~ ENGINEERS ~ CONSU LTANTS EXECUTIVE SUMMARY REPORT Circuit City Store Detention Pond Re-Development 1003 Harvey Road College Station, Texas November 2011 PROJECT ENGINEER Joe I. Gattis, PE #90964, Project Engineer GATTIS Engineering, LLC, Firm #7698 PART 1.1 2010 Moses Creek Ct., College Station, Texas 77845 979-57 5-5022, joe@gattisengineering.com OWNER William Scarmardo 1003 Harvey Road College Station, Texas 77845 979-571-9224, william@scarmardo.com SUB MITT AL DA TE: November 2011 PART 1.2 The SCOPE of this project consists of the re-development of the detention facility located at the Circuit City Store located at 1003 Harvey Road in College Station. The stormwater in-flows to the detention pond facility have decreased since 1995 . The project design is to decrease the size of the current detention facility to accommodate the current stormwater in-flows and allow for improved landscaping and curb appeal. PART 1.3 The Circuit City Store is located at the comer of Harvey Road and Rhett Butler Drive in College Station. The Circuit City Store tract is 3. 09 acres out of an original 5. 05 acre tract. The Delta Gamma House located to the North now sits on the remainder 1.96 acre tract. The project site is located in the Wolf Pen Creek Drainage Basin. The property is located in the unshaded Flood Zone 'X', outside of the 500yr floodplain, as shown on FIRM Map #4804ICOI44 C, dated July 2, 1992. There are no drainage ways or creeks that pass along or through this tract of land. • • • • PART 1.4 The Circuit City Store site consists of an existing 19 ,25 7 square foot building with associated parking lot and landscaped areas. The existing detention facility for this site is located at the front of the property along Harvey Road. The site generally drains from the rear of the property to the front. The stormwater runoff from the site and building roof drainage is captured in the parking lot areas and conveyed to the detention facility via surface sheet flow and curb concentrated flows. Site grades vary from 0.5% to 2.0%. PART 1.5 The stormwater run-off is released into the detention facility by multiple curb-cut openings totaling 18 linear feet located in the southwest comer of the parking lot. The stormwater is then detained and meter-released to the Harvey Road storm sewer system via the existing 2' x 2' steel inlet grate. The inlet grate outfalls into the Harvey Road storm sewer system. The stormwater is then conveyed to an open-ditch drainage channel on the other side of Harvey Road by a 42" reinforced concrete pipe. The detention facility also has an over-flow provided in case of an outlet blockage. The over-flow drains via surface flow to a surface area drain at an existing Harvey Road storm sewer inlet box. PART 1.6 This is the rehabilitation of an existing, previously approved site with an approved drainage report. There are no special permitting requirements associated with any local, state or federal agency. This project requires only a Development Permit to be issued by the City of College Station. PART 1.7 For this site, there is currently an approved drainage design titled 'Drainage Analysis, Circuit City Store, January 1995' by Hester Engineering on file at the City of College Station Development Services Department For this project, please see ADDENDUM #1, Drainage Report for the 'Circuit City Store Detention Pond Re-Development' for a complete hydraulic analysis and design for the re- development of the detention pond. This addendum drainage report consists of 48 pages of hydraulic analysis, calculations and summary with 2 drawings dated November 2011. FIRM# 7698 • 2010 Moses Creek Ct • College Station, Texas 77845 • Tel. 979.575.5022 • Fax 979.690.6888 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) Engineering and Design Professionals Information Engineering Firm Name and Address: Jurisdiction GATIIS Engineering, LLC City: Bryan 20 I 0 Moses Creek Ct. College Station College Station, Texas 77845 Date of Submittal: November I 8 , 20 I I Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: Joe Gattis, PE #909G4; 979-575-5022 JOe@gatt1sengineering.com none Supporting Engineering I Consulting Firm(s): Other contacts: None None Developer I Owner I Applicant Information Developer I Applicant Name and Address: Phone and e-mail: Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: William Scarmardo 979-57 1-9224 I 003 Harvey Rd., CS, Tx 77845 Project Identification Development Name: C1rcu1t City Detention Pond Re-Development Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? This 1s a Site Project. If multi-phase, subject property is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) Timber Ridge Ph 3 , Lot I ,2,3 I 003 Harvey Rd, College Station, Texas 77845 If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. All previous phases were completed by previous developer and are completed. General Location of Project Area, or subject property (phase): Circuit City Store at the corner of Rhett Butler and Harvey Road In City Limits? Bryan: acres. College Station: 3 .09 acres. STORMWATER DESIGN GUIDELINES Effective February 2007 Extraterritorial Jurisdiction (acreage): Bryan: College Station: Acreage Outside ET J: Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continu ed (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: Harvey Road, Rhett Butler Drive Delta Gamma Sorority House Sausalito Apartments Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): None Wolf Pen Creek Drainage Basin Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: unknown Final Plat File #: unknown Date: Name: Status and Vol/Pg: V I 0 I I 8 /Pg I 98 If two plats, second name: Not Applicable File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: C-3 Existing or Proposed ? Existing Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Project D1scuss1on, August 20 I I Alan Gibbs, Enka Bridges Preliminary Report Required? No Submittal Date Oct 2 I • 20 I I Review Date I I -14-20 I I Review Comments Addressed? Yes x No x When? I 1-1 G-1 I -- -- In Writing? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. Previous Drainage Report was completed and approved in January 1995. This 'New' report 1s an addendum. This Addendum #I Report address the site drainage as 1t exists currently and provides hydraulic support data to allow for the size of the current detention pond to be reduced. STORMWATER DESIGN GUIDELI NES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordi nation Dept. Cc ntac t: Date: Subiect: With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? x Yes No ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No x ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): T AMUS Needed? Yes No x ---- Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that obiective in soaces below. Entity Permitted or Approved? US Army Crops of Engineers No x Yes --- US Environmental Protection Agency No x Yes --- Texas Commission on Environmental Quality No x Yes ---- Brazos River Authority No x Yes --- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 Status of Actions (include dates) APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Re-development of existing detention pond facility size t o current drainage in-flows Site _x_ Redevelopment of one platted lot, or two or more adjoining platted lots. Development __ Building on a single platted lot of undeveloped land. Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ Construction of streets and utilities to serve one or more platted lots. Development __ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of The scope of work consists o nly with t he re-sizing and re-development o f t he ProQosed current det ention pond size. No work 1s being performed on the paving areas Project or the build ings . Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No Yes ---- FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I No_X_ Yes __ (Section 11, Paragraph B 1) or a tributary thereof? Is any part of subject property in floodplain I No_X_ Yes Rate Map area of a FEMA-regulated watercourse? -- Encroachment(s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No x -- Yes -- If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. Not Applicable STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (&date) here, and attach copy if not already in City files. x Drainage Analysis, Circuit City Store, January I 995 by Hester Engineering -- Is the stormwater mana~ement plan for the. property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi-phase project, describe stormwater management plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. x Yes Do existing topographic features on subject property store or detain runoff? __ No --Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? ~ No --Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) __ Detention is required. --Need must be evaluated. _x_ Detention not required. What decision has been reached? By whom? Detention will be provided; City College Station it: Gattis Engineering If the need for How was determination made? Type 1 Detention must be evaluated: The decision 1s based on maintaining existing drainage design from 1995. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? x No Yes If yes, --describe splits below. In Part 4 describe design concept for handling this. Watershed or Basin Larger acreage Lesser acreage Above-Project Areas(Section II , Paragraph 83-a) Does Project Area (project or phase) receive ru noff from upland areas? _x_ No --Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? --No --Yes If yes , describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? x No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). STORMWATER DESIGN GUIDELINES Effective February 2007 ' Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert)l Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage If yes, for what part of length? % Created by? __ plat, or easements instrument. If instrument(s), describe their provisions. exist for any -- part of pathway(s)? x No -- Yes -- Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Pathway Not Applicable Areas Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Not Applicable Nearby Drainage Do any of these have hydrologic or hydraulic influence on proposed stormwater Facilities design? x No Yes If yes, explain: ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. Not Applicable Discharge(s) To Lower Property(ies) (Section II , Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No Yes Separate Instrument? x No Yes -- -- Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring --x Pre-development Release (Scenario 2) property(ies)? --Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# ) Not Applicable Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) Detention Facility with grate inlet to control release of stormwater into Harvey Road storm sewer system. Combination: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. Not Applicable If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? No x Yes Explain and provide --documentation. Design will maintain existing drainage design of stormwater outfall into Harvey Road Storm Sewer System. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result in shifting runoff between Basins or Identify gaining Basins or Watersheds and acres shifting: Not Applicable between f--W_h_a_t -d-es-i-gn-a-nd-m-it-ig-a-ti_o_n-is-us_e_d_t_o_c_o_m_p_e_n_sa_t_e_f_or_i_n-cr_e_a-se-d-ru_n_o_ff_---i Watersheds? from gaining basin or watershed? __ x_ No Not Applicable Yes 1. __ With facility(ies) involving other development projects. 2. __ Establishing features to serve overall Project Area. How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 3. __ On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit# ) 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. C'-· -0 Q) CJ) c Q) ffi >-n:: CJ) c Cl "iii Q) 0 Oz (ij ! 1 Are aquatic echosystems proposed? __ No project(s)? __ Yes In which phase(s) or Are other Best Management Practices for reducing stormwater pollutants proposed? __ No __ Yes Summarize type of BMP and extent of use: If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. __ Detention elements __ Conduit elements __ Channel features __ Swales __ Ditches __ Inlets __ Valley gutters __ Outfalls __ Culvert features __ Bridges Other STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No __ Yes Identify type and general size and In which phase(s). Not Applicable If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location , conveyance pathway(s), construction sequence): Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area , is design in substantial conformance with earlier analysis and report for larger area? _x_ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? I Surfaces? C'-· "O CV <J) Steepest side slopes: I Usual front slopes: Usual back slopes: <J) :J CV <J) >- CV I .r:: Flow line slopes: least Typical distance from travelway: .B '6 (Attached Exhibit # ) CV 0 typical greatest "O "iii z "O xi ro 0 Are longitudinal culvert ends in compliance with B-CS Standard Specifications? '- CV Yes No, then explain: '-~ <J) At intersections or otherwise, do valley gutters cross arterial or collector streets? .0 CV No Yes If yes explain: ::, C'-· >---(.) "O I .I::: CV ..... <J) ·-:J :s: '-Are valley gutters proposed to cross any street away from an intersection? Vl CV Q) ~ 0 No Yes Explain: (number of locations?) ~ O>Z ---- ~ ~ x ..... "O I STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? --Yes --No If "no", identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? --Yes --No If no, explain where and why not. C"· "'O (l) (/) Will inlet size and placement prevent exceeding allowable water spread for 10-year ::J ..... (l) design storm throughout site (or phase)? Yes No If no, explain. ~ ---- Cl "'O ~ c "'O co (l) Sag curves : Are inlets placed at low points? Yes No Are inlets and .0 ~ ----..... ·-conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? ::J...., () c Yes No Explain "no" answers. 0 ..c () -- --....,~ '§ (/) a; (l) ..... iii (l) Will 100-yr stormflow be contained in combination of ROW and buried conduit on ..... <( whole length of all streets? Yes No If no, describe where and why. -- -- Do designs for curb, gutter, and inlets comply with 8-CS Technical Specifi cations? Yes --No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? __ No --Yes Identify length(s) and where used. C"· "'O Pipe runs between system I Typical ~ (/) Longest ::J (l) access points (feet): E >-~I Are junction boxes used at each bend? --Yes --No If not, explain where and why. (/) c ·-0 ~z j xj Are downstream soffits at or below upstream soffits? Least amount that hydraulic (/) grade line is below gutter line !!!. Yes No __ If not, explain where and why: --(system-wide): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Describe watercourse(s), or system(s) receiving system discharge(s) below Ul (include design discharge velocity, and angle between converging flow lines). Q) (.) c 1) Watercourse (or system), velocity, and angle? Cll u; c Q) ..... ~o -g E 2) Watercourse (or system), velocity, and angle? ::::J ..... c 0 ·--c . 0 .E .£,.~ E °' ~ °' E J§ 3) Watercourse (or system), velocity, and angle? --Cll ~r/l :J r/l Q) 0 c :"Q ·-> ~ e -0 Q. E .-For each outfall above, what measures are taken to prevent erosion or scour of ..... Q) 0 Q) receiving and all facilities at juncture? --.r::. (/) r/l Q) 1) iii ..... Cll Q. 2) Q) r/l c 3) -9.. Are swale(s) situated along property lines between properties? __ No --Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): C'-· r/l Qi ~ r/l --Q) Flow line slopes (minimum and maximum): r/l >-c ~ I -g 0 rllZ Outfall characteristics for each (velocity, convergent angle, & end treatment). ::::J r/l 1 ~ Cll ::: r/l Q) ..... Will 100-year design storm runoff be contained within easement(s) or platted drainage <( ROW in all instances? --Yes --No If "no" explain: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? x No __ Yes If so, provide the following : VJ Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes No <!) .r:. -- .B Are top of banks separated from road shoulders 2 feet or more? __ Yes No 0 -- <!) Are all ditch sections trapezoidal and at least 1.5 feet deep? --Yes --No -0 For any "no" answers provide location(s) and explain: ·c;; -0 Ill 0 a::: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length : VJ <!) Is 100-year design flow contained in conduit/swale combination? >-Yes No -- --I~ If "no" explain: c Space for 100-year storm flow? ROW Easement Width 0 Ill z (ii Swale Surface type, minimum Conduit Type and size, minimum and maximum x i~ and maximum slopes: slopes, design storm : 0 ~ C'· '6 VJ Qi -0 Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Ill c c >. Ill c .r:. Ill (.) ..... c .E <!) c Access Describe how maintenance access is provided (to swale, into conduit): a. 0 0 :;:; -Ill 0 E :J ..... .~ 0 --c c Instance 2 Describe general location, approximate length: <!) -0 E <!) Ill VJ VJ :J VJ <!) Is 100-year design flow contained in conduit/swale combination? c -0 Yes No 0 ·:;: -- -- ~ 0 If "no" explain : ..... c a. 15 Qi Space for 100-year storm flow? ROW E <!) Easement Width 0 .r:. (.) VJ Swale Surface type, minimum Conduit Type and size, minimum and maximum ...... 2 :J Ill and maximum slopes: slopes, design storm : -0 ..... c Ill 0 a. (.) <!) Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Q; VJ ro c ~ _£. VJ <!) Access Describe how maintenance access is provided (to swale, into conduit): ..... <l'. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters f Continued (Page 4. 7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: c C1l E a. x 0 w ~ :s= ui Is 100-year design flow contained in swale? --Yes --No Is swale wholly 0 Q) within drainage ROW? Yes No Explain "no" answers: c >-:::J I ----..... Q) -~ Q) Access Describe how maintenance access is provide: (.) Q) ..... 0 -z :::J "O xi c 0 (.) Instance 2 Describe general location, approximate length, surfacing: "O Q) ·c C'· :::J (/) ..0 c ::; Q) 0 E £ Q) (/) Is 100-year design flow contained in swale? Yes No Is swale wholly "§ C1l ---- (/) Q) within drainage ROW? __ Yes No Explain "no" answers: ..!!! 0 -- C1l s :!: (/) 0 ~ 0::: Access Describe how maintenance access is provided : -~ :0 :::J c. Instance 31 41 etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened , or straightened) or otherwise altered? No Yes If only slightly ---- C'· shaped, see "Swales" in this Part. If creating side banks, provide information below. "O c Will design replicate natural channel? Yes No If "no", for each instance Q) -----(/) C1l describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year 0 a. c. x design flow, and amount of freeboard: e w c. Instance 1: (/) (/) c Q) Q) >- E I Q) > Instance 2: 0 a. E 0 z a; 1 c Instance 3: c C1l £ u STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? )\ No Yes ----If "ves" provide the information below. W ill small creeks and their floodplains remain undisturbed? __ Yes No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. 'O Q) :J c E Watercourses (and tributaries): Aside from fringe changes, are Regulatory 0 Watercourses proposed to be altered? _x_ No __ Yes Explain below. ~ Ill c Submit full report describing proposed changes to Regulatory Watercourses. Address Q) existing and proposed section size and shape, surfaces, alignment, flow line changes, E Q) length affected, and capacity, and provide full documentation of analysis procedures > 0 and data. Is ful l report submitted? Yes No If "no" explain: ..... --a. E - Qi c c ro All Proposed Channel Work: For all proposed channel work, provide information ..c: u requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? --Yes --No If not, identify location and explain: Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: STORMWATER DESIGN GU IDELINES Effective February 2007 Page 17 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serv ing Subject Property (Phase, or Site) (continued) How many facilities for subject property project? I For each provide info. below. For each dry-type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% 2.1 Oac G, I 80cf 100-yr volume: free flow & plugged 2 ,534cf 3 ,509cf Design discharge (10 yr & 25 yr) I O.OOcfs I 0.83cfs Spillway crest at 100-yr WSE? __ yes x no __ yes no ---- Berms 6 inches above plugged WSE? _x_yes --no __ yes --no Explain any "no" an swers: I 00 year W.S.E. = 290.02' VI Spillway W.S.E. = 290.30' Q) Top of Berm Elev.=291 .00' >- xi For each facility what is 25-yr design Q, an d design of outlet structure? Facility 1: I 0.83cfs, Inlet Grate (2. I 3 sq ~): Depth of Water = I . I' (I 3 .2") 0 z Facility 2: I Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: _x_ Yes No Facility 2: Yes No ------C'· If "no" ex~lain: "O Q) Out et drains directly to storm sewer system in Harvey Road. VI 0 Spillway drains to Harvey Road Right-of-Way. c._ 0 ..... Cl.. For each, what is velocity of 25-yr design discharge at outlet? & at spillway? VI Q) Facility 1: 3.5 fps & 2.55fps Facility 2: & ~ ·0 Are energy dissipation measures used? x No Yes Describe type and <1l ----LL location: c 0 ~ Q) Qi 0 Q) For each, is spillway surface treatment other than concrete? Yes or no, and describe: 4: Facility 1: YES ; Small to Medium Bull Rock Facility 2: For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Small to Medium Bullrock will in h1b1t erosion Facility 2: If berms are used give heights, slopes and surface treatments of sides. Facility 1: Grass Berms, 3: I Slopes, Top W1dth=3'; Top Elev=29 I .00'; Max Height = 2 . 2' Facility 2: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": (/) Facility 1; Yes Q) :;:; =:o-:il Q) Facility 2: LL :::J c c :.;::::; 0 c :.;::::; 0 c (.) Q) ~ Q) For additional facilities provide all same information on a separate sheet. 0 Are parking areas to be used for detention? _x_ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? x No Yes If "yes", provide information in next two boxes. ---- Will 25-yr. flow pass without flowing over driveway in all cases? --Yes --No Without causing flowing or standing water on public roadway? --Yes --No Designs & materials comply with B-CS Technical Specifications? __ Yes --No Explain any "no" answers: C'· (/) Cl c "iii Are culverts parallel to public roadway alignment? __ Yes No Explain: (/) 0 --t; (/) Q) Q) iii >- > I ·;:: Creeks at Private Drives: Do private driveways, drives, or streets cross drainage a. ro ways that serve Above-Project areas or are in public easements/ ROW? -0 0 No Yes If "yes " provide information below. Q) z ----(/) xi :::J How many instances? Describe location and provide information below. (/) t: Q) Location 1: 2: :::J (.) Q) Location 2: ..... <( Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 1 OD-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.11 ) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulato!J! Watercourses {&Tributaries}: Are culverts proposed on these facilities? No __ Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: ~ Arterial or Major Collector Streets: Will culverts serve these types of roadways? Ci) Q) No Yes How many instances? For each identify the .c Ill -- -- Q) location and provide the information below. Ill -ro Instance 1: Q) .... >-~ I~ Instance 2: Instance 3: c 0 o~ Yes or No for the 1 OD-year design flow: 1 2 3 z E xi~ Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E C'-· ro Is velocity limited per conditions (Table C-11)? Ill Ill g'-o Explain any "no" answer(s): ·-c ~ ro 0 c .... 0 CJ +:i >-ro ro u 5: ..Q -0 Q) ro .o 0 ·-........ Minor Collector or Local Streets: Will culverts serve these types of streets? (.) (.) No Yes How many instances? for each identify the ·-Ill -Q) ----.g -0 location and provide the information below: Q_ Q) +-' Q_ Instance 1: ro .?:- -0 >-Instance 2: Q) c Ill ro :J -Instance 3: Ill 0 t: Ill Q) Q) .2: (.) For each instance enter value, or "yes" I "no" for: 1 2 3 :J c u ro Design yr. headwater WSE 1 ft. below curb top? Q) iii .... c <( ·-100-yr. max. depth at street crown 2 feet or less? Q) 0 Product of velocity (fps) & depth at crown (ft) = ? E .... g Is velocity limited per conditions (Table C-11 )? Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? Yes No If not, -- --identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? __ No __ Yes If yes , identify location (s) and provide justification: 'O Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? Q) --No --Yes If "yes" identify location(s), describe outfall design treatment(s): :::I c ~ 0 -2. <Fl t: Q) Is scour/erosion protection provided to ensure long term stability of culvert structural > ::i (.) components, and surfacing at culvert ends? __ Yes __ No If "no" Identify locations and provide justifi cation(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? __ Yes --No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with 8-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELI NES Effective February 2007 Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? )'.. No Yes ----If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? Ci) Q) Ol -c ·c en A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: ~ Pollution Prevention ro Plan (SW3P) I) Silt Fencing Around All Dirt Work ::J a established for 2) Sand Bags around ex1tsing inlet grate L.. project construction? 3) Silt Fence $ Hay Bale Combo at Spillway (1) iii s No x Yes ---- Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? x No Yes If "yes" list general type and location below. ---- Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised , and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? STORMWATER DESIGN GUIDELINES Effective February 2007 Yes ---- Page 22 of 26 No If "no" explain: APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements Channel features ---- Culvert features Swales Ditches Inlets Outfalls ---------- __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: · 1) 2) 3) 4) 5) Design Parameters Hydrology Is a map(s) showing all Design Drainage Areas provided? _x_ Yes --No Briefly summarize the range of applications made of the Rational Formula: The Rational Metod wa5 u5ed to evaluate the 2. I 0 acre5 that feed th15 detention pond facility. The Rational Method wa5 u5ed to develop Hydrograph5 for PERVIOUS and IMPERVIOUS surfaces and produce an estimated stormwater run-off. These surfaces included roof drainage. paved parking lot, and landscaped areas. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? 2. I 0 acres STORMWATER DESIGN GUIDELINES Effective February 2007 Location (or identifier): Roof Drainage $ Parking Lot Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? No x Yes In approximately what percent of Design Drainage Areas? 70 % As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? _x_ No --Yes If "yes" identify type of data, source(s), and where applied : For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets N/A Storm drain system for local streets N/A Open channels 2,5, I 0,25,50 , I 00 100 Swale/buried conduit combination in lieu of channel N/A Swales N/A Roadside ditches and culverts serving them N/A Detention facilities: spillway crest and its outfall 2,5, I 0 ,25,50, I 00 100 Detention facilities: outlet and conveyance structure(s) 2,5, I 0 ,25,50, I 00 100 Detention facilities: volume when outlet plugged 100 100 Culverts serving private drives or streets N/A Culverts serving public roadways N/A Bridges: provide in bridge report. N/A Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) 4.13fps Lowest (feet per second) 3 .51 fps Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For conduit type(s) STORMWATER DESIGN GUIDELINES Effective February 2007 For street gutters: Page 24 of 26 n=O.O 13 Coefficients: APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? x No Yes Head and friction losses x No Yes -- ------ Explain any "yes" answer: Not Applicable In conduit is velocity generally increased in the downstream direction? --Yes --No Are elevation drops provided at inlets, manholes, an d junction boxes? --Yes --No Explain any "no" answers: Not Applicable Are hydraulic grade lines calculated and shown fo r design storm? --Yes --No For 100-year flow conditions? --Yes --No Explain any "no" answers: Not Applicable What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Not Applicable Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? __ Yes __ No If "no" list locations and explain : Not Applicabl e Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Not Applicable Entrance, friction and exit losses: Bridges Provide all in bri dge report STORMWATER DESIGN GUIDELINES Effective February 2007 Not Applicable Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2009 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version , the date of the version, any applicable patches and the publisher • AutoCad Land Desktop 2005, Civil Design 2005; • Hydra Flow Hydragraphs 2007, Hydra flow Express 2007 Part 5 -Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: In the hydraulic re-design of the detention fa cility at the re-fashioned C1rcu1t City Store, I have, to the best of my knowledge, instituted new drainage measures to make this drainage facility perform as originally designed and to meet the standards as set forth 1n the B/CS Unified Drainage Design Guidelines. Attestation ngineer 9tJ?fo J( } STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of 26 Re · February 2009 Fi ,<pt-:#{&, '1 ~ pATTISENGINEERIN~ ENGINEERS ~ CONSULTANTS 2010 Moses Creek Ct. •College Station, Texas 77845 • P: 979.S7S.S022 •Firm #7698 DRAINAGE REPORT Addendum#l Circuit City Store Detention Pond Re-Development 1003 Harvey Road College Station, Texas Prepared for: William Scarmardo I 003 Harvey Road College Station, Texas 77845 November 23, 2011 GE# 020002 -~~'''"'~· ~ ~E OF /.~\:\., -..,_'"(,P........ ., ' ~ ""··~·· U' ~*. . ) ~*:j;, -... *" l············k't.~~~ Z JOE I. GATTIS Z ~-·~·················~ la~·.< 90964 :~ 2 .,0.:.•.f.c c NS f:.':e•~<ffe ,I ~. ~.ss • • • • • • 0~""""' ,, 10 ALE~ ~~ CERTIFICATION "I, Joe I. Gattis, PE #90964 certify that this report for the drainage design for the re-developed Circuit City Store Project in College Station, Texas, was prepared by me in accordance with the provisions of the Bryan/College Station Unified Stormwater Design Guidelines for the owners thereof. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued." GATIIS ~4''~~"· ,.:;-' :'i€. OF I~ .,,, ~c..~~e•••••e~.n ' ---..... ~ ··" . ii!' .i . ' ~/:ii. It\ J.c1,.·.\l , ................... ~ 2 OEl.GATIIS 2 ~··~··············:··I fj ~·· < 90964 Q .. $2 ,,,0~•/ CE NS~ •• ~~~ '· ~.s~ ••••• ·~\G' ~ '\~IONAL €.\, ~~ AM "°'7{/f'b p,tv -- PATTISENGINEERIN~ ENGINEERS + CONSULTANTS 2010 Moses Creek Ct., College Station, Texas 77845 • P: 979.575.5022 • Finn #7698 DRAINAGE ADDENDUM #1 CIRCUIT CITY STORE DETENTION RE-DEVELOPMENT November 2011 PROJECT INFORMATION The vacated Circuit City Store located at the intersection of Rhett Butler Drive and Harvey Road in College Station, Texas, has been remodeled and transitioned into an existing office building. The project site consists of the existing 19,257 square foot building, surrounding parking lot, loading dock area, landscaping and grass detention pond on 3.09 acres. This Drainage Report is an Addendum to the existing drainage design report 'Drainage Analysis, Circuit City Store, January 1995 'Hester Engineering. The existing Detention Pond Facility located at the front of the property along Harvey Road was designed to handle the storm water run-off of the original 5. 05 acre tract that extended from University Oaks Boulevard to Harvey Road. See Attachment #1 for the 1995 'Site grading & Drainage Plan Sheet. ' With the development of the Sorority and Fraternity houses at the comer of Rhett Butler Drive and University Oaks Boulevard, the applicable storm water in-flows to the Circuit City Detention Pond have decreased. Thus, tms report will address the existing drainage patterns of the 3. 09 acre Circuit City Store site as it drains cu"ently today with the purpose of adjusting the existing detention facility located at the front of the property for more efficient use of street frontage for landscaping and curb appeal PROPERTY HYDRAULIC INFORMATION The subject property is located in the Wolf Pen Creek Drainage Basin. The property is relatively flat with grades between 1 % and 3%. The rear and western side of the building's grassy areas generally drain to the west towards the Sausalito Apartments' parking lot where the storm water run-off is ultimately conveyed to the Harvey Road drainage system. The remainder of the site (paved areas, building and landscaping) drains into the parking lot and thus to the detention pond at the front of the property along Harvey Road. The property is located in the un-shaded Flood Zone "X", outside of the 500-Yr. flood plain, as shown on FIRM (Flood Insurance Rate Map), Map No: 48041C0144 C, dated July 2, 1992. REVISED CIRCUIT CITY STORE -1 -GAITIS ENGINEERING Drainage Pond Drainage Basin: The watershed basin that in-flows to the detention pond facility consist of the all site parking and paving associated landscaped areas, down- spouts for the building roof drainage and the detention facility itself totaling 2.10 acres. The run-off from this basin sheet flows across the parking lot in a southerly direction to wards Harvey Road and is localized at a curb-cuts at the southern most comer where it is captured into the existing detention facility . The water is then detained by the current 2' x 2' inlet grate (Grate #1) outfall structure and released into the Harvey Road storm sewer system. Existing grate is a Vulcan V-8157-1 (A=2.13 sq. ft). HYDRAULIC & RUN-OFF CALCULATIONS The "Rational Method" (Q) was used to determine storm water run-off for all basins included within the subject property . The equation approximates storm water run-off production in cubic feet per second ( cfs ). Rational Method -Q=C*I*A The runoff Coefficients (C) for the hydraulic model were determined by type of land cover and grade as shown in the Unified Stormwater Design Guidelines. A coefficient of C=0.35 was used for undeveloped natural grasslands and developed landscaped areas. With respect for the impervious areas such as buildings, sidewalks, and pavements, a coefficient of C=0.9 was used for the calculations. AREA Over-All Site (3 .09 ac) Weighted 'C' 0.62 Re-Developed Drainage Basin (2.1 Oac) *See Attaclnnent #3 for Weighted 'C' Data Sheet 0.75 Intensity ffi was determined by calculating the Time of Concentration (Tc) for each particular basin's longest flow path. Being that this subject property is minimal in size, the required minimum standard of Tc= IO minutes was used for calculation purposes. The watershed total Area (A) is in acres. Please see Attachment #3 for ' Tc & Intensity ' Calculations Summary Sheet. Other resources used to calculate and model the hydraulics of the project were JntelliSOLVE Hydra.flow Hydrographs 2007 for hydrograph generation and detention pond design. JntelliSOLVE Hydra.flow Express 2007 application was used to develop and determine open channel flow characteristics and capacities. All hydrographs and support data are attached herein. The hydraulic performance for the outfall structure (Grate #1) for the Detention Pond was determined by the Orifice Equation and Weir Equation, respectively. ORIFICE: Q=4.82* Ag*y 112 ; WEJR: Q=Cw*L*Hi.s; REVISED CIRCUIT CITY STORE Q=Capacity in cubic feet per second Ag=Orifice Area (sq. ft.) y=Effective Head on orifice Cw=3.00 (interpolated for broad crested weir) L=Length of weir crest H=Height of energy grade above crest elevation -2-GATTIS ENGINEERING BUILDINGS The existing building is 19,257 square feet in size and will remain unchanged. No new buildings will be added to this site. PROJECT DRAINAGE SUMMARY & DESIGN The storm water run-off patterns for this site will remain un-changed with the re- development of the detention facility. Currently, storm water run-off from the site drains to the Sausalito Apartments, Rhett Butler and Harvey Road right-of-ways, and the detention facility. See Attachment #1 for Drainage Basin Summary Map. Sausalito Apartments Drainage Area 0. 62 acres The grassy areas behind the Circuit City building and also along the western property are currently sloped towards the Sausalito property line due to 15 years of weathering, erosion and ground movement/expansion. The storm water run-off sheet flows over grassland to the apartments' parking lot, where it is thus conveyed to the Harvey Road storm sewer system. Rhett Butler & Harvey Rd. Right-of-Ways 0.37 acres The landscaped areas adjacent to these right-of-ways currently slope towards these streets due to natural weathering and erosion of 15 years. The storm water run-offs from these areas sheet flow to the above referenced streets where they intercepted by inlet grates along Rhett Butler or the curb-and-gutter of Harvey Road. The run-off is then conveyed to the Harvey Road storm sewer system. Detention Pond Facility 2.10 acres This area consists of all the storm water run-off from the site that is captured into the parking lot and conveyed to the existing detention pond. This includes the roof drainage from the building and some surrounding landscaped areas that are graded towards the parking lot. The original size of the detention pond was approximately 70' by 125 ' (0.200 acres,+/-7, 700 cubic feet). Upon completion of the re-development of the detention pond, its new dimensions are approximately 63 ' x 70' x 70.5' x 34.5' (0.127 acres, 6, 180 cubic feet). With the decrease in the watershed basin requiring detention, we have decreased the over-all size of the pond by 0.073 acres(+/-1,520 cubic feet). Please see Table 1 below for the summ of the storm water un-off of the site. Table 1 DRAINAGE BASIN PEAK RUNOFF (cfsl SUMMARY 2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr Run-Off to Right ofWays: 0.83 1.00 1.12 1.28 1.44 1.46 Run-Off to Apartments: 1.39 1.67 1.87 2.14 2.42 2.44 Run-OfftoDetentionPond: 10.06 12.12 13.60 15.53 17.56 17.71 DetentionPondDischarges: 8.21 9.45 10.00 10.83 11.72 11.77 *See Attachment #4 for Site Hydrographs & Pond Stage Storage I Discharge Graphs Existing Site Run-Off (3 .09ac): 10.86 13.10 14.75 16.87 19.09 19.29 Total Site Run-Offw/Detention: 10.07 11.76 12.50 13.54 14.67 14.76 Net Decrease: -0.79 -1.34 -1.21 -3.33 -4.42 -4.53 *See Attachment #5 for Total Site Hydrograph Comparisons REVISED CIRCUIT CITY STORE -3-GATTIS ENGINEERING As shown in Table 1, the re-developed detention pond under current site drainage conditions performs as designed by detaining the storm water run-off captured. Please see Attachment #4 for Total Site Hydrographs. DETENTION POND & CHANNEL PERFORMANCE Parking Lot Curb-Cuts (Outfall) As described earlier, the detention pond drainage basin storm water flows over the parking lot, accumulates along the curb-n-gutters in the southern most corner where it is released into the detention pond facility via curb-cuts. Originally, there was an under- sized 2' wide curb-cut opening for all storm event flows thus resulting in 'over-topping' of the curb and erosion. In order to fully accommodate the 100 year storm event of 17. 71 cfs without over- topping, the 'WEIR Equation' listed above was used for outfall analysis. The re-designed detention facility will now have 18 linear feet of curb-cut openings, an existing 2' opening along with four other 4' wide curb cuts (outfall points). This results in a depth of 0.48' (5.76") at the curb-cut outfall points for a 100 year storm event. See Attachment #6 for Curb-Cut X-Section (100 yr). Detention Pond The top of berm elevation of the detention pond is 291.00' with an emergency over-flow elevation of290.30'. The existing top of grate elevation is 288.70'. During a 50 Year Storm Event, the water surface elevation of the pond is 290.01 ' with a free-board of 0.99'. During a 100 Year Storm Event, the water surface elevation of the pond is 290.02' with a free-board of0.98'. Table 2 POND & FLUME/CHANNEL PERFORMANCE 2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr Pond Water Surface Elevation: 289.40' 289.55 ' 289.66' 289.83 ' 290.01 ' 290.02' Det. Pond Total Storage (C.F.): 885 1,204 1,516 1,982 2,494 2,534 DetentionPondDischarges: 8.21 9.45 10.00 10.83 11.72 11.77 Detention Pond Freeboard: 1.60' 1.45' 1.34' 1.17' 0.99' 0.98' *See Attachment #4 for Site Hydrographs & Pond Stage Storage I Discharge Graphs Channel/Flume Peak Flow (cfs): 10.06 12.12 13 .60 Channel/Flume Depth (ft.): 0.89 1.01 1.09 *See Attachment #6 for Flume/Channel Cross-Sections Detention Pond Over-Flow 15.53 1.19 17.56 1.29 17.71 1.29 In the event of the detention pond outflow interruption (inlet grate blockage), an over- flow discharge route has been provided over the berm at an elevation of290.30' to keep storm water from over-topping the berm. The storm water will over-flow at the specified over-flow point and drain via surface flow over grass for approximately 40 feet where it enters an existing surface area drain at the back of an existing Harvey Road storm sewer curb inlet box. REVISED CIRCUIT CITY STORE -4-GATTIS ENGINEERING IN SUMMARY, from the infonnation presented in this report, it is shown that the proposed re-development of the Circuit City Store detention pond in College Station, Texas, will be in compliance with the Bryan -City of College Station's Unified Stonnwater Design Guidelines. Respectfully Submitted, GATTIS ENGINE G ttis, P.E. Li ns Ci Professional Engineer REVISED CIRCUIT CITY STORE -5- ~~''''"· ,,,#"' :1;E. OF rs-.i:'\\ ~c::,~~······~.s-·•• ~1.-·;1_z;k-uit;· •• 1*tl, l···"'···············rJ 2 JOE I. GATIIS 2 g •• ~··············:··1 fj ~·· < 90964 :472 ,,,O~•/ CE NS ~~·~«I /ii!' \. ~.s~ ••••• ·~,0-.;: 6' '\~IO L;; GATIISENGINEERING ATTACHMENT #1 ORIGINAL DRAINAGE & GRADING MAP CURRENT DRAINAGE BASIN MAP REVISED CIRCUIT CITY STORE -6-GATTIS ENGINEERING • 'A' 4> I I L_ GRATE INLET NOT TO SCALE GRADING AND DRAINAGE PLAN OUTFALL STRUCTURE 1/"t'-1·-<:f' \ ) I I I I I I I I I I 0 <{ 0 O'.'. >-w GENERAL NOTES: NO MIA...., l:OUl"Yl:NT Ofll 9TOC:-: ,-UHQ 0# MATl:fl:IAI,. -.t.. alC •u .. o~o \lllllTMIN 'THI: O~t'lll Of' 1HI[ M.MAINIHO ~l:ltS. 8fr:\ ... i~°"AU.SM~s~'" AU. 111:0AOWAYS Clc:A.11 0# I.IUD ANO :'11:1~~ss~:~,~~~cr~ T~ LA'l'O: OF OltOAH!C MAl1:fll:IAL. 9CW..10 •co •ll'tl•4 0, Ol:TENnON ••llN Aftl'."- ~~~~~~~ C~~A~~ ~r~~T t.~TTHI -...&.ES 011 S~AnCH 1'1:NC!NO. E.:kfi~:t~~~!.T'~~;;.::r~H'¥-'st~ti!~r'flOM irDl~,~~T\il~~la~~f~ff!l!•~~O~'.iNP¥'MT l~J:~~!&\~~~~~~li~:f~~~,t{~~J ~I[ Ttd: OOt-ITtU.Oroft •HAI.I. •I: ftCS.,ON•a1..C: ,.Of' IUM0\11"'0 AU.. st.Ott.ll:Mt COH'W'tOI.. OC:\llOl:S M~ T1'11[ OOHSTl"'VOT!OH IS CO...,.Ll:TE ANO 1111:: ~Nn:O AftltAS HAVI: at:I: ... STA9ll.IZCO. Kit ,. ... \11:1.11[ ... .,. Ol:TAIL Slooll:l:l' ... o. COHC•1:n: wons. \ > O'.'. <{ I SILT FENCE PLACEMENT SILT FENCE I I I 9A3lfll~im..a.o u ·-u•ite....o.JU: ...... ' CONCRETE FLUME AT DETENTION BASIN 9ENCHMA.l'tK .&. -i-~ !:.!~:UPW. -~NO TOP OF F'lRE HYOA~ N<>R'™£AST CORNER OF RHITT-BUTL.ER OR. AND HARVEY ROAD. ·~-·u~~·::tt1 BASIN OVERFLOW 3/r-1·-r:r E:LCV. :29.Z.4~ ~~E.::G~~~[ Of" N#1 D:CAVAf'IOH, cou.tot n ...no.t -OK*.WI" Qt.0901 -'7 ... -.HIO U>C STAA GAS -lollC;l""-l:L •AUtC -1'H-11J.4 01'1 -OliHHT ~A~ -111-t~1 ~O[ .. ;fA~~C. --•,'t,;/1.:~ -114-3MO TYPE 'W' MICROSTORE I 1511 COLLEGE STATION, TElcAS TX C2.1 ~orll90HA1. Of' MeotO: lllOU4&1C!!!!\M· -tOl-1• ATTACHMENT #2 Re-DEVELOPED DETENTION FACILITY REVISED CIRCUIT CITY STORE -7-GATTIS ENGINEERING ATTACHMENT #3 Tc & Rainfall Intensity Calculations Weighted 'C' Data Sheet REVISED CIRCUIT CITY STORE -8-GA ms ENGINEERING I .. I GATTIS ENGINEERING ENGINEERS -$-CONSULTANTS Tc & INTENSITY CALCULATIONS SUMMARY SHEET Revised C1rcu1t City Store Detention November 2011 -GE020002 EXISTING CONDITIONS -TIME OF CONCENTRATION (Tc) LENGTH VELOCITY TYPE OF FLOW (feet) (fps) PRE-DEVELOPED Overland Flow (-1%) 117 0.8 Shallow Concentrated-(2%) 84 2.8 Shallow Concentrated (-0.5%) 467 1.4 Channel Flow (-2.6%) 69 2.4 I U IAL (mtn) - TIME (min.) 2.4 0.5 5.6 0.5 9.0 {-Nu 1 t:: 10 Minutes 1s Mtntmum) PROPOSED CONDITIONS -TIME OF CONCENTRATION (Tc• LENGTH VELOCITY TIME TYPE OF FLOW (feet) (fps) (min.) DEVELOPED Overland Flow (-1%) 62 0.8 1.3 Shallow Concentrated-(2%) 84 2.8 0.5 Shallow Concentrated (-0.5%) 467 1.4 5.6 Channel Flow (-2.6%) 69 2.4 0.5 I TOT AL ~min~ = 10.0 Intensity= b/(Tc + d)Ae I RAINFALL INTENSITY DIFFERENTIAL SUMMARY Brazos County Existing Intensity Proposed Intensity (±)Difference Yr b d e (in.hr.) (in.hr.) (in./hr.) 2 65 8.0 0.806 6.62 6.33 -0.30 5 76 8.5 0.785 8.04 7.69 -0.34 10 80 8.5 0.763 9.01 8.63 -0.37 25 89 8.5 0.754 10.28 9.86 -0.42 50 98 8.5 0.745 11.62 11 .15 -0.47 100 96 8.0 0.73 12.14 11.64 -0.50 *Texas Highway Department-Bridge Division Hydraulic Manual, 3/2004 I I I - PATTIS ENGINEERIN~ ENGINEERS + CONSULTANTS Weighted Runoff Coefficients (C) Calculations Sheet CIRCUIT CITY DETENTION POND RE-DEVELOPMENT NOVEMBER 2011 Runoff Weighted DESCRIPTION AREA (ac.) Coefficient 'C' Factor OVER-ALL SITE Landscaping I Grass 1.56 0.35 0.18 Pavement I Bldg. 1.53 0.90 0.45 OVER-ALL SITE= 3.09 Total Weighted "C" = 0.62 Runoff Weighted DESCRIPTION AREA (ac.) Coefficient 'C' C' Factor RE-DEVELOPED DETENTION BASIN Landscaping I Grass 0.57 0.35 0.10 Pavement I Bldg. 1.53 0.9 0.66 RE-DEVELOPED DETENTION BASIN= 2.10 Total Weighted "C" = 0.75 REVISED CIRCUIT CITY STORE ATTACHMENT #4 HYDROGRAPHS TABLE OF CONTENTS -9-GA ms ENGINEERING - Hydraflow Table of Contents Circuit City .gpw Hydranow Hydrographs by lntelisolve v9.22 Monday, Nov 28, 2011 Hydrograph Return Period Recap ............................................................................ 1 2 -Year Summary Report ....................................................................................................................... 2 Hydrograph Reports . . . . . ... ....... ...... ... . ......... ....... .. . . .......... .. . . . . . . . . . . ....... .. . .. . .. . . ............ ... . . . . . . . . .. . . . . 3 Hydrograph No. 1, Rational, Detained Drainage Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Hydrograph No. 2, Reservoir, Detention Pond . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pond Report -Front Pond .................................................................................................. 5 Hydrograph No. 3, Rational, Right of Ways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Hydrograph No. 4, Rational, Sausalito Apartments . . . .. .. .. .. . . . . . . . . . .. . .. .. . .. . .. . . . . . . . . . . .. .. . . . . . . . . . . . .. . . . . 7 Hydrograph No. 5, Combine, Post Total Site Drainage .......................................................... 8 Hydrograph No. 6, Rational, Existing Site Drainage ............................................................... 9 5 -Year Summary Report ..................................................................................................................... 10 Hydrograph Repor'ts . . .. . .. .. ......... .............. ............ ... . ... .. . .. ... . . . ........ ......... .. . . . . .. . . .... .. . ... . . . ... ...... 11 Hydrograph No. 1, Rational, Detained Drainage Basin .. . . . .. . . . .. .. .. . .. .. .. . .. . . . . . .. . . . . . . . . . .. . .. . . . . . .. . . 11 Hydrograph No. 2, Reservoir, Detention Pond .. . . .. .. .. .. .. .. .. . .. .. .. .. . . .. .. .. . .. . .. . .. .. .. .. . . . .. . . .. . .. . .. .. .. 12 Hydrograph No. 3, Rational, Right of Ways . . . . .. . .. .. . .. .. . .. . . . . . . . . .. .. . . . . . .. . . . . . .. .. .. . .. .. .. . . . . . .. . . .. .. .. . . . 13 Hydrograph No. 4, Rational, Sausalito Apartments .............................................................. 14 Hydrograph No. 5, Combine, Post Total Site Drainage ... .. . .. . .. . .. . . .. ... ................. ... .... . ........ .. 15 Hydrograph No. 6, Rational, Existing Site Drainage .. .. . . .. .. . . .. .. .. .. . . .. . .. . .. .. . .. .. .. .. . .. .. . .. .. .. . .. .. .. . 16 10 -Year Summary-Report ................................................... .................................................................. 17 Hydrograph Reports . . ... . . ............... .. . ... ......... .. . ... ........ ..... .. . . . . ... . ....... ......... .. . ...... ...... .. . .. ... .. .. . . 18 Hydrograph No. 1, Rational, Detained Drainage Basin .. .. .. . .. .. .. .. .. .. .. .. .. . .. .. . .. .. .. .. .. . .. .. . .. . .. .. .. 18 Hydrograph No. 2, Reservoir, Detention Pond .. . . . . . . . . . . . .. .. .. .. . .. .. . .. .. . .. . . . . .. .. .. .. . . . . . . . . .. .. .. . .. .. .. .. 19 Hydrograph No. 3, Rational, Right of Ways .......................................................................... 20 Hydrograph No. 4, Rational, Sausalito Apartments . . . . .. . . .. .. .. .. . . .. .. .. . .. . .. .. .. .. .. .. . .. . . .. . . .. . . .. . . . . .. . 21 Hydrograph No. 5, Combine, Post Total Site Drainage ........................................................ 22 Hydrograph No. 6, Rational, Existing Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 25-Year Summary Report . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . 24 Hydrograph Repom . ............... .. ... .. . ........ ... . . . . .................. .. . ... . ....... .. . .. . . . . . . ..... .... ... .. . . . .. . . . . . . .. .. 25 Hydrograph No. 1, Rational, Detained Drainage Basin . . . . . .. . . . .. . . . . . . . .. .. . . . . . .. . .. . . . .. . . . . . . . . . . . . . . . . . . 25 Hydrograph No. 2, Reservoir, Detention Pond .. .. . .. . .. .. .. . . .. . . . .. .. . .. .. .. .. .. .. .. .. . .. . . . . .. . .. .. . . .. . .. .. . .. . 26 Hydrograph No. 3, Rational, Right of Ways .......................................................................... 27 Hydrograph No. 4, Rational, Sausalito Apartments .. . .. .. .. .. . .. . . .. . .. .. .. .. .. .. .. .. .. .. .. . .. . .. .. .. . .. .. .. . .. . 28 Hydrograph No. 5, Combine, Post Total Site Drainage ........................................................ 29 Hydrograph No. 6, Rational, Existing Site Drainage . .. .. . .. .. .. . . .. .. .. .. .. .. .. . . . .. .. .. . .. .. .. .. .. .. .. .. .. .. .. . 30 50 -Year Summary Report ..................................................................................................................... 31 Hydrograph Repor'ts ... . . . . . . . . . ................. .. ............. .. . . .. . .......... ...... .. .. . . . . . . . ... ...... ................ .. . . .. .. 32 Hydrograph No. 1, Rational, Detained Drainage Basin .. .. . . . .. .. . . .. .. . .. . .. .. .. . . .. . .. .. .. . .. .. . .. .. . .. .. .. . 32 Hydrograph No. 2, Reservoir, Detention Pond ..................................................................... 33 ~"rlrn1u·Qnn f.Jn ~ QQtinnQI Qinht nf \/\IQ\/Q ~4!1 Contents continued ... Circuit City .gpw Hydrograph No. 4, Rational, Sausalito Apartments .. . . . . .. . . . . .. . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .. . .. .. . 35 Hydrograph No. 5, Combine, Post Total Site Drainage ........................................................ 36 Hydrograph No. 6, Rational, Existing Site Drainage .. . . .. . . . . .. .. . . .. .. . .. .. .. .. . . . . .. . . .. .. . .. .. . . . . .. . . . .. . . . . 37 100 -Year Summary-Report ..................................................................................................................... 38 Hydrograph Reports ................................................................................... ............................ 39 Hydrograph No. 1, Rational, Detained Drainage Basin .. . . . . . . . . . . . . . .. . .. .. .. . . . . . .. .. . .. .. .. . . .. . .. .. . .. . .. . 39 Hydrograph No. 2, Reservoir, Detention Pond ..................................................................... 40 Hydrograph No. 3, Rational, Right of Ways .......................................................................... 41 Hydrograph No. 4, Rational, Sausalito Apartments . .. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. . . . . . . . . . . . . . . . 42 Hydrograph No. 5, Combine, Post Total Site Drainage ........................................................ 43 Hydrograph No. 6, Rational, Existing Site Drainage . .. . . . .. . . . .. . .. . . . . . . . . . . . . . . .. . . . . . . . . . . .. . .. . . .. . . . . . .. . . . 44 1 ydrograph Return Period Recap Hydraflow Hydrographs by lntelisolve v9.22 Hydrograph Inflow Peak Outflow (cfs) I Hydrograph type Hyd(s) l description (origin) 1-Yr 2-Yr 3-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr I Rational ----10.06 --12.12 13.60 15.53 17.56 17.71 I Detained Drainage Basin Reservoir I ~-I -1 8.2131 ·-1 9.4521 10.00 I 10.83 111.721 11.77 Detention Pond Rational --0.828 --0.996 1.118 1.277 1.444 1.456 Right of Ways Rational I·-I -I 1.387 I -I 1.669 I 1.874 I 2.140 I 2.419 I 2.440 Sausalito Apartments Combine 12, 3, 4 I -110.071 --111.761 12.50 I 13.54 I 14.67 I 14.76 I Post Total Site Drainage Rational I ----10.86 --13.10 14.75 16.87 19.09 19.29 Existing Site Drainage ~ 2 ydrograph Summary Report Hydrallow Hydrographs by lntelisolve v9.22 Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph type flow interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) Rational 10.06 10 6,039 Detained Drainage Basin Reservoir 8.21 3 12 6,039 289.40 885 Detention Pond Rational 0.828 10 497 Right of Ways Rational 1.387 10 832 Sausalito Apartments Combine 10.07 11 7,367 2,3,4 Post Total Site Drainage Rational 10.86 13 8,474 Existing Site Drainage Hydrograph Report Hydrallow Hydrographs by lntelisolve v9.22 Hyd. No. 1 Detained Drainage Basin Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 2 yrs = 1 min = 2.100 ac = 6.390 in/hr IDF Curve = Brazos County Rainfall. IDF *Composite (Area/C) = ((1 .530 x 0.90) + (0.570 x 0.35)] / 2.100 Detained Drainage Basin Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 3 Monday, Nov 28, 2011 = 10.06 cfs = 10 min = 6,039 cuft = 0.75* = 10.00 min = 1/1 Q (cfs) Hyd. No. 1 --2 Year Q (cfs) 12.00 .-----.----.------.---,.----,.----,-----,------,.---..----~ 12.00 0.00 _____ ___.___ __ __._ __ __.L ___ ..__ __ _,__ __ ___,__ __ ___L_ __ ___.1. ___ L__ _ ____.:~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) Hydrograph Report Hydraflow Hydrographs by lntelisolve v9.22 Hyd. No. 2 Detention Pond = Reservoir = 2 yrs = 1 min Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. Detention Pond Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 4 Monday, Nov 28, 2011 = 8.213 cfs = 12 min = 6,039 cuft = 289.40 ft = 885 cuft Q (cfs) Hyd. No. 2 --2 Year Q (cfs) 12.00 -.,-----r----r----..----.,.-----.--~--~--~--~--~--~ 12.00 0.00 ...-:,. __ .....__ __ .J....._ __ L_ _ ___JL__ _ ___L __ __L __ __L __ _l_ __ _L_ __ -ll........;::::.i~ 0.00 0 2 4 6 8 10 12 14 16 18 20 22 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 885 cuft Time (min) - Pond Report Hydraftow Hydrographs by lntelisolve v9.22 Pond No. 1 -Front Pond Pond Data Contours • User-<lefined contour areas. Average end area method used for volume calculation. Begining Elevation = 288.70 ft Stage I Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Iner. Storage (cuft) Total storage (cuft) 0.00 288.70 00 0 0 0.30 289.00 1,223 183 183 0.80 289.50 2,290 878 1,062 1.30 290.00 3,362 1,413 2,475 1.80 290.50 3,705 1,767 4,241 2.30 291.00 4,048 1,938 6,1 80 Culvert I Orifice Structures Weir Structures [A] [BJ [C] [PrfRsrJ [AJ [BJ [CJ Rise (In) Inactive 0.00 0.00 0.00 Crest Len (ft) Inactive 0.00 0.00 Span (in) = 17.50 0.00 0.00 0.00 Crest El. (ft) = 288.70 0.00 0.00 No. Barrels = 1 0 0 0 WeirCoeff. = 3.33 3.33 3.33 Invert El. (ft) = 288.70 0.00 0.00 0.00 Weir Type = Riser Length (ft) = 0.00 0.00 0.00 0.00 Multi-Stage = Yes No No Slope(%) = 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Contour) Multi-Stage = n/a No No No TW Elev. (ft) = 0.00 5 Monday, Nov 28, 2011 [DJ 0.00 0.00 3.33 No Note: Culvert/Orifice outllows are analyzed under inlet (ic) and outlet (oc) control. Vlleir ri-• checked for orifice conditions (ic) and submergence (a). Stage (ft) Stage I Discharge Elev (ft) 3.00 ~----~----~----~-----~----~----~----~----~ 291 .70 0.00 -'--='-----'-------'--------'-----L-------'-------'------'-------'--288.70 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 -TotalQ Discharge (cfs) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 2 yrs = 1 min = 0.370 ac = 6.390 in/hr IDF Curve = Brazos County Rainfall. IDF Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 / / / / / / v / / Right of Ways Hyd. No. 3 --2 Year ~ I\.. / ~ ~ '\ I\. Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact ~ ~ '\ ~ 6 Monday, Nov 28, 201 1 = 0.828 cfs = 10 min = 497 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 ~ 0.30 0.20 '\ ' ~ 0.10 0 2 4 6 8 10 12 14 16 18 0.00 20 -HydNo.3 Time (min) Hydrograph Report Hydrallow Hydrographs by lntelisolve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 2 yrs = 1 min = 0.620 ac = 6.390 in/hr IDF Curve = Brazos County Rainfall. IDF Sausalito Apartments Hyd. No. 4 -2 Year Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 7 Monday, Nov 28, 2011 = 1.387 cfs = 10 min = 832 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 0.00 ____ _.__ __ __.__ __ __,_ __ ___L._ __ __1.. __ ---l. __ ___J ___ J_ __ .l..._ _ ____::!lil.-0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type Storm frequency Time interval Inflow hyds. Q (cfs) = Combine = 2 yrs = 1 min = 2,3,4 Post Total Site Drainage Hyd. No. 5 -2 Year 8 Monday, Nov 28, 2011 Peak discharge = 10.07 cfs Time to peak = 11 min Hyd. volume = 7,367 cuft Contrib. drain. area = 0.990 ac Q (cfs) 12.00 10.00 0.00 1~~~~:::E::::r==j::r::t::::t::::3::~J~!!!llli.1~===-1 0.00 0 2 4 6 8 10 12 14 16 18 20 22 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type = Rational Storm frequency = 2 yrs Time interval = 1 min Drainage area = 3.090 ac Intensity = 5.671 in/hr IDF Curve = Brazos County Rainfall. IDF * Composite (Area/C) = ((1.500 x 0.90) + (1 .590 x 0.35)] / 3.090 Q (cfs) 12.00 10.00 - Existing Site Drainage Hyd. No. 6 -2 Year V\ v I\ J \. 9 Monday, Nov 28, 2011 Peak discharge = 10.86 cfs Time to peak = 13min Hyd. volume = 8,474 cuft Runoff coeff. = 0.62* Tc by User = 13.00 min Ase/Rec limb fact = 1/1 Q (cfs) 12.00 10.00 8.00 v \ 8.00 J " v \ I " v \ -1 1 ~ "" ~ I/ ' v I\ 6.00 4.00 2.00 0.00 6.00 4.00 2.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 -HydNo.6 Time (min) 10 Hydrograph Summary Report Hydrallow Hydrographs by lntelisolve v9.22 Hyd. Hydrograph Peak Time rmeto Hyd. Inflow Maximum Total Hydrograph No. type flow interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) Rational 12.12 10 7,270 Detained Drainage Basin 2 Reservoir 9.452 12 7,270 289.55 1,204 Detention Pond 3 Rational 0.996 10 598 Right of Ways 4 Rational 1.669 10 1,002 Sausalito Apartments 5 Combine 11 .76 11 8,869 2,3,4 Post Total Site Drainage 6 Rational 13.10 13 10,216 Existing Site Drainage Hydrograph Report Hydraftow Hydrographs by lnteli&olve v9.22 Hyd. No. 1 Detained Drainage Basin Hydrograph type Storm frequency Time interval Drainage area Intensity IDF Curve = Rational = 5 yrs = 1 min = 2.100 ac = 7.693 in/hr = Brazos County Rainfall. IOF •Composite (Area/C) = [(1 .530 x 0.90) + (0.570 x 0.35)) / 2.100 Q (cfs) Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 11 Monday, Nov 28, 2011 = 12.12 cfs = 10 min = 7,270 cuft = 0.75* = 10.00 min = 1/1 14.00 -.----.-----.------,,---,-----.-----.-------..----,.-----,-----,- Q (cfs) 14.00 12.00 10.00 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 2 Detention Pond Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = Reservoir = 5 yrs = 1 min = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. Q (cfs) Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 12 Monday, Nov 28, 2011 = 9.452 cfs = 12 min = 7,270 cuft = 289.55 ft = 1 ,204 cuft Q (cfs) 14.00 .-----.,.----.----.----.-----,.----,----.,------.----.,----.-----r-14.00 0.00 -#C.--.J__ _ __JL__ _ __L __ ___J__ __ _J_ __ __L__ __ L_ _ __l __ _L __ ~_;:::::._ 0.00 0 2 4 6 8 10 12 14 16 18 20 22 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 1,204 cuft Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 5 yrs = 1 min = 0.370 ac = 7.693 in/hr IDF Curve = Brazos County Rainfall. !OF Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 I I I v I I I v Right of Ways Hyd. No. 3 - 5 Year I \ I/ \ Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact \ \ \ \ \ 13 Monday, Nov 28, 2011 = 0.996 cfs = 10 min = 598 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 \ 0.30 0.20 \ \ 0.10 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.3 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type Storm frequency Time interval Drainage area Intensity IDF Curve a (cfs) = Rational = 5 yrs = 1 min = 0.620 ac = 7.693 in/hr = Brazos County Rainfall. !OF Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 14 Monday, Nov 28, 2011 = 1.669 cfs = 10 min = 1,002 cuft = 0.35 = 10.00 min = 1/1 a (cts) 2.00 .----.---r----,------.--~-----,,..-----r-----.----~--~ 2.00 1.00 0.00 ~---'------'-----'-----'-----l--___JL.._ __ L._ __ .l..._ __ _l_ __ ~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type Storm frequency Time interval Inflow hyds. = Combine = 5 yrs = 1 min = 2, 3,4 Post Total Site Drainage Hyd. No. 5 --5 Year 15 Monday, Nov 28, 2011 Peak discharge = 11. 76 cfs Time to peak = 11 min Hyd. volume = 8,869 cuft Contrib. drain. area = 0.990 ac Q (cfs) 0.00 1~~k::::::::JE:::I::=t:::::r::t::E::~~:::J~~l~====l 0.00 0 2 4 6 8 10 12 14 16 18 20 22 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) .. Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 5 yrs = 1 min = 3.090 ac = 6.837 in/hr IDF Curve = Brazos County Rainfall. IDF • Composite (Area/C) = ((1 .500 x 0.90) + (1 .590 x 0.35)) / 3.090 Q (cfs) 14.00 12.00 ,_ ·-- Existing Site Drainage Hyd. No. 6 --5 Year /\'- v I\ Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 16 Monday, Nov 28, 201 1 = 13.10 cfs = 13 min = 10,216 cuft = 0.62* = 13.00 min = 1/1 Q (cfs) 14.00 12.00 8.00 v \ 10.00 10.00 8.00 v \ ·-v \ v \ l/·-\ 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 -HydNo.6 Time (min) 17 ydrograph Summary Report Hydraftow Hydrographs by lntelisolve v9.22 Hydrograph Peak Time rmeto Hyd. Inflow Maximum Total Hydrograph type flow Interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (curt) (ft) (cuft) Rational 13.60 10 8,160 Detained Drainage Basin Reservoir 10.00 13 8,160 289.67 1,516 Detention Pond Rational 1.118 10 671 Right of Ways Rational 1.874 10 1, 124 Sausalito Apartments Combine 12.50 11 9,955 2,3,4 Post Total Site Drainage Rational 14.75 13 11,505 Existing Site Drainage 18 Hydrograph Report Hydraftow Hydrographs by lntellsolve v9.22 Monday, Nov 28, 2011 Hyd. No. 1 Detained Drainage Basin Hydrograph type = Rational Peak discharge = 13.60 cfs Storm frequency = 10 yrs Time to peak = 10min Time interval = 1 min Hyd. volume = 8,160 cuft Drainage area = 2.100 ac Runoff coeff. = 0.75* Intensity = 8.635 in/hr Tc by User = 10.00 min IDF Curve = Brazos County Rainfall. IDF Ase/Rec limb fact = 1/1 • Composite (Area/C) = ((1.530 x 0.90) + (0.570 x 0.35)) / 2.100 a (cfs) a (cfs) 14.00 .------,-----,----...,,-----,-----.-----.-----r----.,-----...------.-14.00 12.00 0.00 _,_ __ __._ __ ___J_ __ __JL__ __ ..L.._ __ _J__ __ __l_ __ __J_ __ __JL_ __ J__ __ ~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) - Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 2 Detention Pond Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = Reservoir = 10 yrs = 1 min = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. Q (cfs) Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 19 Monday, Nov 28, 201 1 = 10.00 cfs = 13 min = 8, 160 cuft = 289.67 ft = 1,516 cuft Q (cfs} 14.00 .-----r-----.---.---r-----,----.----.-------.----.----~----.---~ 14.00 0.00 _____ ..___ _ ___.._ __ _,__ __ L__ _ __l.,_ __ __J__ __ L__ _ ____L __ __L_ _ _____JI..--~--~ 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 1,516 cuft Time (min) Hydrograph Report Hydrallow Hydrographs by lntelisolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity IDF Curve a (cfs) = Rational = 10 yrs = 1 min = 0.370 ac = 8.635 in/hr = Brazos County Rainfall.IDF Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 20 Monday, Nov 28, 2011 = 1.118 cfs = 10 min = 671 cuft = 0.35 = 10.00 min = 1/1 a (cfs) 2.00 .,.---.----.-----r-----.----r-----.,,...----.----~--~--~ 2.00 o.oo .... o"'---------'---'-----...1..__--...l.__--_l_--_j_--__L_--_l._-----1..--~ o.oo 2 4 6 8 10 12 14 16 18 20 -HydNo.3 Time (min) ... Hydrograph Report Hydrallow Hydrographs by lntelisolve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 10 yrs = 1 min = 0.620 ac = 8.635 in/hr IDF Curve = Brazos County Rainfall. !OF Sausalito Apartments Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 21 Monday, Nov 28, 2011 = 1.874 cfs = 10 min = 1, 124 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) Hyd. No. 4 -10 Year Q (cfs) 2.00 .----.----.----,-----.-----r-----.---.-----.,...---~--~ 2.00 0.00 ~---'-------i------'------'------1-----....l---L---J__--..J.._--~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type Storm frequency Time interval Inflow hyds. Q (cfs) = Combine = 10 yrs = 1 min = 2,3,4 22 Monday, Nov 28, 2011 Peak discharge = 12.50 cfs Time to peak = 11 min Hyd. volume = 9,955 cuft Contrib. drain. area = 0.990 ac Q (cfs) 14.00 .---.------,.---~---,-----r---~--..------,.--~--~--~ 14.00 0.00 1~~~~:::E::3::::!::I::t:=E::~::::::::::J~-l~~l 0.00 0 2 4 6 8 10 12 14 16 18 20 22 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 10 yrs = 1 min = 3.090 ac = 7.699 in/hr IDF Curve = Brazos County Rainfall. IDF • Composite (Area/C) = ((1 .500 x 0.90) + (1 .590 x 0.35)] I 3.090 Existing Site Drainage Hyd. No. 6 - 1 O Year Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 23 Monday, Nov 28, 2011 = 14.75 cfs = 13 min = 11 ,505 cuft = 0.62* = 13.00 min = 1/1 Q (cfs} 0.00 ___ __._ __ ...__. _ _,__ _ __L __ _,__ _ __i_ __ L_ _ _L_ _ __l. __ ...L_ _ _L _ ___JL__,1. 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 -HydNo.6 Time (min) 24 ydrograph Summary Report Hydraflow Hydrographs by lntelisolve v9.22 Hydrograph Peak Time Time to Hyd. In ft ow Maximum Total Hydrograph type now interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) Rational 15.53 10 9,319 Detained Drainage Basin Reservoir 10.83 13 9,319 289.83 1,982 Detention Pond Rational 1.277 10 766 Right of Ways Rational 2.140 10 1,284 Sausalito Apartments Combine 13.54 11 11 ,369 2,3,4 Post Total Site Drainage Rational 16.87 13 13,158 Existing Site Drainage .. Hydrograph Report Hydraftow Hydrographs by lntellsolve v9.22 Hyd. No. 1 Detained Drainage Basin Hydrograph type Storm frequency Time interval Drainage area Intensity IDF Curve = Rational = 25 yrs = 1 min = 2.100 ac = 9.861 in/hr = Brazos County Rainfall. IDF • Composite (Area/C) = [(1.530 x 0.90) + (0.570 x 0.35)) / 2.100 Q (cfs) 25 Monday, Nov 28, 201 1 Peak discharge = 15.53 cfs Time to peak = 10min Hyd. volume = 9,319 cuft Runoff coeff. = 0.75* Tc by User = 10.00 min Ase/Rec limb fact = 1/1 Q (cfs) 18.00 .----.----.-----,,-----.----.----..-------r------i.----.,..----,.-18.00 15.00 0.00 ____ __._ __ __._ __ ___Jc__ __ ..J...._ __ -1..._ __ ___l_ __ __L __ ___JL_ __ J__ __ ~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) Hydrograph Report Hydraftow Hydrographs by lntellsolve v9.22 Hyd. No. 2 Detention Pond = Reservoir = 25 yrs = 1 min Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. Detention Pond Hyd. No. 2 --25 Year Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 26 Monday, Nov 28, 2011 = 10.83 cfs = 13 min = 9,319 cuft = 289.83 ft = 1,982 cuft Q (cfs) 0.00 ----~~---'----'-----''------'----'----.JL----L--....l.__-----.ll"----.l.....;;::ii-""-0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 1,982 cuft Time (min) Hydrograph Report Hydraftow Hydrographs by lntellsolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 25 yrs = 1 min = 0.370 ac = 9.861 in/hr IDF Curve = Brazos County Rainfall. IDF Right of Ways Hyd. No. 3 --25 Year Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 27 Monday, Nov 28, 201 1 = 1.277 cfs = 10 min = 766 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 0.00 -----~--~--~--~--~--~---~--~--~----0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo. 3 Time (min) Hydrograph Report Hydrallow Hydrographs by lnteli&olve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type Storm frequency Time interval Drainage area Intensity IDF Curve Q (cfs) = Rational = 25 yrs = 1 min = 0.620 ac = 9.861 in/hr = Brazos County Rainfall. IDF Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 28 Monday, Nov 28, 201 1 = 2.140 cfs = 10 min = 1,284 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 3.00 .....-----..-------.-------.----..,...----..-----.---.----..----.....-----.-3.00 0.00 ----~--~--~--~--__._ __ ___. ___ .__ __ ,__ __ _.__ _____ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) Hydrograph Report Hydranow Hydrographs by lntellsolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type Storm frequency Time interval Inflow hyds. = Combine = 25 yrs = 1 min = 2,3,4 29 Monday, Nov 28, 201 1 Peak discharge = 13.54 cfs Time to peak = 11 min Hyd. volume = 11 ,369 cuft Contrib. drain. area = 0.990 ac Post Total Site Drainage Q (cfs) Hyd. No. 5 -25 Year Q (cfs) 14.00 -,-----,----,----.-----r---....--------..---,.--~r---~--~-~--~ 14.00 0.00 1e~:::::::i::::t:j::r:j::r::3~§:~:::"!!-t~1~_1 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 25 yrs = 1 min = 3.090 ac = 8.805 in/hr IDF Curve = Brazos County Rainfall. IDF • Composite (Area/C) = [(1 .500 x 0.90) + (1 .590 x 0.35)] I 3.090 Existing Site Drainage Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 30 Monday, Nov 28, 2011 = 16.87 cfs = 13 min = 13, 158 cuft = 0.62* = 13.00 min = 1/1 Q (cfs) Hyd. No. 6 --25 Year Q (cfs) 18.00 --,----r---,----.----..---r-----...-----,.-----.----""T""---.-----.------.----,-18.00 0.00 ___ __._ __ ..__ _ __._ _ __,_ __ ..L-_ _.._ __ ,___ _ __.__ _ __,_ __ _.___----'------'--.31.-0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 -HydNo.6 Time (min) 31 ydrograph Summary Report Hydrallow Hydrographs by lntelisolve v9.22 Hydrograph Peak rme rmeto Hyd. Inflow Maximum Total Hydrograph type flow interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) Rational 17.56 1 10 10,535 ----I Detained Drainage Basin Reservoir 11.72 1 13 10,535 1 290.01 2,494 Detention Pond Rational 1.444 1 10 866 ----Right of Ways Rational 2.419 1 10 1,451 ----Sausalito Apartments Combine 14.67 1 11 12,852 2,3,4 ---Post Total Site Drainage Rational 19.09 1 13 14,894 ----Existing Site Drainage .. Hydrograph Report Hydraflow Hydrographs by lntelisolve v9.22 Hyd. No. 1 Detained Drainage Basin Hydrograph type = Rational Storm frequency = 50 yrs Time interval = 1 min Drainage area = 2.100ac Intensity = 11 .148 in/hr IDF Curve = Brazos County Rainfall. IDF •Composite (Area/C) = ((1.530 x 0.90) + (0.570 x 0.35)) / 2.100 Q (cfs) Detained Drainage Basin Hyd. No. 1 --50 Year 32 Monday, Nov 28, 2011 Peak discharge = 17.56 cfs Time to peak = 10 min Hyd. volume = 10,535 cuft Runoff coeff. = 0.75* Tc by User = 10.00 min AsdRec limb fact = 1/1 Q (cfs) 18.00 ....------..---~-----.---...-----.-----..---~-----.---...-----..--18.00 0.00 --------'-----'-------'----'-----'------'-----'-------'----'----~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 2 Detention Pond = Reservoir = 50 yrs = 1 min Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. a (cfs) Detention Pond Hyd. No. 2 -50 Year Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 33 Monday, Nov 28, 2011 = 11 .72 cfs = 13 min = 10,535 cuft = 290.01 ft = 2 ,494 cuft a (cfs) 18.00 -.-------.r---~---.-------.r---~---.------,r---~---.------,r---~---,-18.00 0.00 -------''------'-----'------''------'-----'------''------'-----'------'1---....i..-.....-i--0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 2,494 cuft Time (min) Hydrograph Report Hydranow Hydrographs by lntelisolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 50 yrs = 1 min = 0.370 ac = 11 . 148 in/hr IOF Curve = Brazos County Rainfall. !OF Q (cfs) Right of Ways Hyd. No. 3 -50 Year Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 34 Monday, Nov 28, 201 1 = 1.444 cfs = 10 min = 866 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 2.00 ~---,.----.-----..-----.------.-------.------,,-----.,....---.,.----..,-2.00 0.00 -----~--~--~--~--~--~----''----"'----~-----0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.3 Time (min) - Hydrograph Report Hydranow Hydrographs by lntelisolve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 50 yrs = 1 min = 0.620 ac = 11 .148 in/hr IDF Curve = Brazos County Rainfall. !OF Sausalito Apartments Hyd. No. 4 --50 Year Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 35 Monday, Nov 28, 2011 = 2.419 cfs = 10 min = 1,451 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) 0.00 ------'------'-----'------'------1.-----'---'-----'----....L..,_--.3i.-0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type Storm frequency Time interval Inflow hyds. Q (cfs) = Combine = 50 yrs = 1 min = 2,3,4 Post Total Site Drainage Hyd. No. 5 -50 Year 36 Monday, Nov 28, 2011 Peak discharge = 14.67 cfs Time to peak = 11 min Hyd. volume = 12,852 cuft Contrib. drain. area = 0.990 ac Q (cfs) 15.00 -,....------.----r---.----....---.....----.-----.-------,.-------.----..-----,----,.-15.00 0.00 1~J::::::::::i=::t:1::[:j::t::~~====~ ..... -l_J~:::.i 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) - Hydrograph Report Hydraflow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type = Rational Storm frequency = 50 yrs Time interval = 1 min Drainage area = 3.090 ac Intensity = 9.967 in/hr IDF Curve = Brazos County Rainfall. IDF • Composite (Area/C) = ((1 .500 x 0.90) + (1 .590 x 0.35)] / 3.090 Q (cfs) 21 .00 18.00 ---,..._ Existing Site Drainage Hyd. No. 6 -50 Year /\. , "' I \: Peak discharge = Time to peak = Hyd. volume = Runoff coeff. = Tc by User = Ase/Rec limb fact = - 37 Monday, Nov 28, 2011 19.09 cfs 13 min 14,894 cuft 0.62* 13.00 min 1/1 Q (cfs) 21.00 18.00 ;· l'\ 15.00 15.00 12.00 12.00 9.00 I/ I/ v v 6.00 3.00 0.00 0 2 4 6 8 10 12 -HydNo.6 14 16 'I\ I\ - I\ - I\ 9.00 6.00 3.00 18 20 22 24 0.00 26 Time (min) 38 Hydrograph Summary Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. Hydrograph Peak Time rmeto Hyd. In ft ow Maximum Total Hydrograph No. type flow interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuf't) (ft) (cuft) Rational 17.71 10 10,625 Detained Drainage Basin 2 Reservoir 11 .77 13 10,625 290.02 2,534 Detention Pond 3 Rational 1.456 10 874 Right of Ways 4 Rational 2.440 10 1,464 Sausalito Apartments 5 Combine 14.76 11 12,963 2,3,4 Post Total Site Drainage 6 Rational 19.29 13 15,044 Existing Site Drainage - Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 1 Detained Drainage Basin Hydrograph type = Rational Storm frequency = 100 yrs Time interval = 1 min Drainage area = 2.100ac Intensity = 11 .243 in/hr IDF Curve = Brazos County Rainfall. IDF •Composite (Area/C) = [(1.530 x 0.90) + (0.570 x 0.35)] / 2.100 a (cts) Detained Drainage Basin Hyd. No. 1 -100 Year 39 Monday, Nov 28, 2011 Peak discharge = 17.71 cfs Time to peak = 10 min Hyd. volume = 10,625 cuft Runoff coeff. = 0.75* Tc by User = 10.00 min Ase/Rec limb fact = 1/1 a (cts) 18.00 ~--~------.------,---.....-----.----~------.------,---...------..-18.00 0.00 ____ _..._ __ --L-__ ___. ___ ~--~--_..._ __ -..L.. __ ___. ___ ~-----0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.1 Time (min) - Hydrograph Report Hydranow Hydrographs by lntelisolve v9.22 Hyd. No. 2 Detention Pond Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name = Reservoir = 100 yrs = 1 min = 1 -Detained Drainage Basin = Front Pond Storage Indication method used. Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage 40 Monday, Nov 28, 2011 = 11.77 cfs = 13 min = 10,625cuft = 290.02 ft = 2,534 cuft Detention Pond Q (cfs) Hyd. No. 2 --100 Year Q (cfs) 18.00 ~--~-~--~--~-~--~--~-~--~--~-~--~ 18.00 0.00 ~-___Jc__ _ ___..L_ __ __J__ _ ___Jc__ _ ___..L_ __ __J__ _ ___Jc__ _ ___..L_ __ __.1___--311 __ __,__.....;;:__ 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.2 -HydNo.1 111111111111111111111 Total storage used = 2,534 cuft Time (min) - Hydrograph Report Hydrallow Hydrographs by lntellsolve v9.22 Hyd. No. 3 Right of Ways Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 100 yrs = 1 min = 0.370 ac = 11 .243 in/hr IDF Curve = Brazos County Rainfall. IDF Right of Ways Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 41 Monday, Nov 28, 2011 = 1.456 cfs = 10 min = 874 cuft = 0.35 = 10.00 min = 1/1 Q (cfs) Hyd. No. 3 -100 Year Q (cfs) 2.00 -.-----.--------.-----r----.----r------.,...----~--~--~--~ 2.00 1.00 0.00 ____ _.,_ __ _..._ __ ___._ __ ___._ __ --1. __ __JL__ __ L__ __ .l__ __ _J__ _ ___:~ 0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.3 Time (min) Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 4 Sausalito Apartments Hydrograph type = Storm frequency = Time interval = Rational 100 yrs 1 min Drainage area = 0.620 ac Intensity = 11 .243 in/hr IDF Curve = Brazos County Rainfall. !OF Q (cfs) Sausalito Apartments Hyd. No. 4 -100 Year 42 Monday, Nov 28, 2011 Peak discharge = 2.440 cfs Time to peak = 10 min Hyd. volume = 1,464 cuft Runoff coeff. = 0.35 Tc by User = 10.00 min Ase/Rec limb fact = 1/1 Q (cfs) 0.00 ___ _._ __ _.__ __ ~ __ _.._ __ __._ __ __.1. __ ____. ___ .__ __ .J__ __ :!i-0.00 0 2 4 6 8 10 12 14 16 18 20 -HydNo.4 Time (min) .. Hydrograph Report Hydraftow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Post Total Site Drainage Hydrograph type = Combine Storm frequency = 100 yrs Time interval = 1 min Inflow hyds. = 2, 3, 4 Q (cfs) Post Total Site Drainage Hyd. No. 5 -100 Year 43 Monday, Nov 28, 2011 Peak discharge = 14. 76 cfs Time to peak = 11 min Hyd. volume = 12,963 cuft Contrib. drain. area = 0.990 ac Q (cfs) 15.00 -,----,----r---,....-------r----r-------r---.-----.---~--~-~--~ 15.00 0.00 1eJ~~f:::t:j~:I:j::f::j~::::~...:-L.::::J~~i 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 -HydNo.5 -HydNo.2 -HydNo.3 -HydNo.4 Time (min) - Hydrograph Report Hydranow Hydrographs by lntelisolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Storm frequency Time interval Drainage area Intensity = Rational = 100 yrs = 1 min = 3.090 ac = 10.068 in/hr IDF Curve = Brazos County Rainfall. IDF *Composite (Area/C) = ((1.500 x 0.90) + (1 .590 x 0.35)] / 3.090 Q (cfs) 21.00 18.00 - Existing Site Drainage Hyd. No. 6 --100 Year /\. -1 \ Peak discharge Time to peak Hyd. volume Runoff coeff. Tc by User Ase/Rec limb fact 44 Monday, Nov 28, 2011 = 19.29 cfs = 13 min = 15,044 cuft = 0.62* = 13.00 min = 1/1 -- - - Q (cfs) 21 .00 18.00 15.00 I \ - - 15.00 12.00 12.00 3.00 I/ \ - -I -\ I ~ I -\ 9.00 9.00 6.00 6.00 3.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 -HydNo.6 Time (min) ATTACHMENT #5 TOTAL SITE PRE-& POST-HYDROGRAPHS REVISED CIRCUIT CITY STORE -10 -GATTIS ENGINEERING Multi-Hydrograph Plot Hyd. No. 5 Post Total Site Drainage Hydrograph type = Combine Peak discharge = 10.07 cfs Time to peak = 11 min Hyd. Volume = 7,367 cuft Hydraflow Hydrographs by lnteUsolve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Peak discharge Time to peak Hyd. Volume = Rational = 10.86 cfs = 13 min = 8,474 cuft Post Total Site Drainage through Existing Site Drainage Q (cfs) 2-yr frequency Q (cfs) 12.00 -,--------~------~------~------~ 12.00 0.00 ----------'------------'--------.........L----------'-0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) Multi-Hydrograph Plot Hyd. No. 5 Post Total Site Drainage Hydrograph type = Combine Peak discharge = 11 . 76 cfs Time to peak = 11 min Hyd. Volume = 8,869 cuft Hydraflow Hydrographs by lntetisotve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type = Rational Peak discharge = 13.1 O cfs Time to peak = 13 min Hyd. Volume = 10,216 cuft Post Total Site Drainage through Existing Site Drainage Q (cfs) 5-yr frequency Q (cfs) 14.00 ~------~------~------~------~ 14.00 0.00 -#'----------'-----------'---------_._ ______ __._ 0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) - Multi-Hydrograph Plot Hyd. No. 5 Post Total Site Drainage Hydrograph type = Combine Peak discharge = 12.50 cfs Time to peak = 11 min Hyd. Volume = 9,955 cuft Hydraflow Hydrographs by lnteli&Olve v9.22 Hyd. No. 6 Existing Site Drainage Hydrograph type Peak discharge Time to peak Hyd. Volume = = = = Rational 14.75 cfs 13 min 11 ,505 cuft Post Total Site Drainage through Existing Site Drainage Q (cfs) 10-yr frequency Q (cfs) 15.00 ~------~------~------~------~ 15.00 0.00 -----------~----------'---------"'-------~ 0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) Multi-Hydrograph Plot Hydraflow Hydrographs by lntelisolve v9.22 Hyd. No. 5 Hyd. No. 6 Post Total Site Drainage Existing Site Drainage Hydrograph type = Combine Hydrograph type = Rational Peak discharge = 13.54 cfs Peak discharge = 16.87 cfs Time to peak = 11 min Time to peak = 13 min Hyd. Volume = 11,369 cuft Hyd. Volume = 13, 158 cuft Post Total Site Drainage through Existing Site Drainage Q (cfs) 25-yr frequency Q (cfs) 18.00 ~------~------~-------~------~ 18.00 0.00 _________ __._ ______ ____. _______ ........_ ______ _.._ 0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) - Multi-Hydrograph Plot Hydraflow Hydrographs by lnteti&otve v9.22 Hyd. No. 5 Hyd. No. 6 Post Total Site Drainage Existing Site Drainage Hydrograph type = Combine Hydrograph type = Rational Peak discharge = 14.67 cfs Peak discharge = 19.09 cfs Time to peak = 11 min Time to peak = 13 min Hyd. Volume = 12,852 cuft Hyd. Volume = 14,894 cuft Post Total Site Drainage through Existing Site Drainage a (cfs) 50-yr frequency a (cfs) 21.00 ~---------------------------~ 21 .00 0.00 ----------~------~------~------~ 0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) - Multi-Hydrograph Plot Hydraflow Hydrographs by lntetisolve v9.22 Hyd. No. 5 Hyd. No. 6 Post Total Site Drainage Existing Site Drainage Hydrograph type = Combine Hydrograph type = Rational Peak discharge = 14.76 cfs Peak discharge = 19.29 cfs Time to peak = 11 min Time to peak = 13 min Hyd. Volume = 12,963 cuft Hyd. Volume = 15,044 cuft Post Total Site Drainage through Existing Site Drainage Q (cfs) 100-yr frequency Q (cfs) 21.00 ~------~------~------~------~ 21 .00 0.00 ------------~------~------~------~ 0.00 0 5 10 15 20 -HydNo.5 -HydNo.6 Time (min) ATTACHMENT #6 DETENTION POND FLUME I CHANNEL X-SECTIONS CURB-CUT 100 YEAR X-SECTION REVISED CIRCUIT CITY STORE -11 -GATTIS ENGINEERING - Channel Report Hydraflow Express by lntelisolve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291.00 290.50 290.00 289.50 289.00 288.50 0 \ .5 \ \ , = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 10.06 \ \ \ 1 1.5 Section v "=' 2 2.5 3 Reach (ft) Tuesday, Nov 22 2011 Highlighted Depth (ft) = 0.89 Q (cfs) = 10.06 Area (sqft) = 2.87 Velocity (ft/s) = 3.51 Wetted Perim (ft) = 4.83 Crit Depth, Ye (ft) = 0. 70 Top Width (ft) = 3.45 EGL (ft) = 1.08 j I I I 3.5 4 4.5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 5 Channel Report Hydraflow Express by lntelisolve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z: 1) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291 .00 290.50 290.00 289.50 . 289.00 288.50 0 - ' .5 l , = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 12.12 \ , \ 1 1.5 2 Section v -- 2.5 3 Reach (ft) Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (fVs) Wetted Perim (ft) Crit Depth, Ye (ft) Top Width (ft) EGL (ft) , I J 3.5 4 Tuesday, Nov 22 2011 = 1.01 = 12.12 = 3.29 = 3.69 = 5.08 = 0.79 = 3.51 = 1.22 4.5 5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 Channel Report Hydraflow Express by lntelisolve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z: 1) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291.00 290.50 \ 290.00 1 289.50 289.00 288.50 0 .5 = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 13.60 ' \ \ 1 1.5 2 Section v -- 2.5 3 Reach (ft) Tuesday, Nov 22 2011 Highlighted Depth (ft) = 1.09 Q (cfs) = 13.60 Area (sqft) = 3.57 Velocity (ft/s) = 3.81 Wetted Perim (ft) = 5.25 Crit Depth, Ye (ft) = 0.85 Top Width (ft) = 3.55 EGL (ft) = 1.32 , I J 3.5 4 4.5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 5 - Channel Report Hydraflow Express by lntelisolve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291 .00 290.50 \ = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 15.53 290.00 \ \ \ \ 289.50 289.00 288.50 0 .5 1 1.5 2 Section v -- 2.5 3 Reach (ft) Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth, Ye (ft) Top Width (ft) EGL (ft) I I J 3.5 4 Tuesday, Nov 22 2011 = 1.19 = 15.53 = 3.92 = 3.96 = 5.45 = 0.92 = 3.60 = 1.43 4.5 5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 Channel Report Hydraflow Express by lntetisolve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z: 1) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291 .00 290.50 290.00 289.50 289.00 288.50 0 \ , .5 ' = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 17.56 ' \ 1 1.5 2 Section v -- 2.5 3 Reach (ft) Tuesday, Nov 22 2011 Highlighted Depth (ft) = 1.29 Q (cfs) = 17.56 Area (sqft) = 4.29 Velocity (ft/s) = 4.10 Wetted Perim (ft) = 5.66 Crit Depth, Ye (ft) = 1.00 Top Width (ft) = 3.65 EGL (ft) = 1.55 I 7 1 ) ) ~ 3.5 4 4.5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 5 Channel Report Hydraflow Express by lntelisotve Detention Pond Flume I Channel Trapezoidal Botom Width (ft) Side Slopes (z: 1 ) Total Depth (ft) Invert Elev (ft) Slope(%) N-Value Calculations Compute by: Known Q ( cfs) Elev (ft) 291 .00 290.50 290.00 289.50 289.00 288.50 0 \ , .5 \ = 3.00 = 0.25, 0.25 = 1.50 = 289.00 = 0.45 = 0.020 Known Q = 17.71 \ \ \ 1 1.5 2 Section v -=- 2.5 3 Reach (ft) Highlighted Depth (ft) Q (cfs) Area (sqft) Velocity (ft/s) Wetted Perim (ft) Crit Depth, Ye (ft) Top Width (ft) EGL (ft) , j , ' I J 3.5 4 Tuesday, Nov 22 2011 = 1.29 = 17.71 = 4.29 = 4.13 = 5.66 = 1.00 = 3.65 = 1.56 4.5 5 Depth (ft) 2.00 1.50 1.00 0.50 0.00 -0.50 - Weir Report Hydraflow Express by lntelisolve Parking Lot Curb Cut-100 Year Storm Event Rectangular Weir Crest = Sharp Bottom Length (ft) = 18.00 Total Depth (ft) = 0.50 Calculations Weir Coeff. Cw Compute by: Known a ( cfs) = 3.00 Known a = 17.71 Highlighted Depth (ft) a (cts) Area (sqft) Velocity (ft/s) Top Width (ft) Depth (ft) Parking Lot Curb Cut -100 Year Storm Event 1.00 0.50 0.00 -0.50 0 2 --Weir 4 6 --w.s. 8 ~ --- 10 12 14 16 18 Monday, Nov 28 2011 = 0.48 = 17.71 = 8.56 = 2.07 = 18.00 20 22 Depth (ft) 1.00 0.50 0.00 -0.50 Length (ft)