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HomeMy WebLinkAbout29 Development Permit 387 College Station Junior HighDETENTION POND ACCUMULATED VOLUMES FROM KLING ENGR & SURVEYING REPORT JULY 1989 A1--1ii ACCUMULATED AREA 2 VOLUME ELEVATION (FT2) (FT2) (FTJ) 307.4 0 0 0 308 5,350 2,675 1,338 308 .5 10,400 7,875 3,938 309 18, 125 14,263 7,131 309.5 25,000 21,563 10,781 310 33 ,925 29,463 14,731 310.5 40,000 31 ,963 18,481 311 46 ,800 43,400 21,700 TOTAL AVAILABLE STORAGE-78 ,100 ft3 Top of Berm Elevation -311 .2 DETENTION POND VOLUMES - REVISED GRADING ORIGINAL ACCUMULATED ACCUMULATED VOLUME ELEVATION VOLUME (FT3) (FTJ) 309 12,407 12,609 310 37,919 44,520 311 78,100 119,216 NEW VOLUMES EXCEED ORIGINAL DESIGN VOLUME (FTJ) 0 1,338 5,276 12,407 23,188 37,919 56,400 78,100 /. -' CHEATHAM AND · .ASSOCIATES October 18, 1999 City of College Station P.O. Box 9960 College Station, Texas 77842 Attn: Mr. Jeff Tondre Re: A&M Consolidated Middle School Detention Facility Request for Comments/Clarification Engineer's Project No. 1019-215 Dear Mr. Tondre: Bill Savage of College Station ISD recently informed us that he met with the City concerning the most recent rendition of the referenced detention facility. According to him, the City has requested that Cheatham & Associates look at raising the berm and outlet structure to elevation 304.00. He further revealed that the City desires more detention from the proposed facility than is planned under the current configuration. We would be happy to look at the City's proposal, but we need further detail and clarification on what the City wants. Please provide answers to the following questions: 1. Increasing detention in the facility would require altering the outlet V-notch as well as raising the berm. Is this what the City desires? 2. What maximum water surface elevation behind the outlet does the City desire? 3. What is the City's target discharge from the pond for each frequency? Please note that this is affected by the answers to numbers 1 and 2. 4. Does the City propose to increase the pond grading to provide additional storage? If so, by what percent increase in volume? 5. If the water surface in the pond is increased above the current proposed configuration, the 100-year water surface will increase by more than 1 foot at the upstream end of the school's property. Will the City, as the floodplain administrator, and FEMA accept this? 6 . Will a CLOMR and/or LOMR be required for the City's proposed configuration? We ask that you provide a written letter response to these questions so that we may investigate the proposed configuration as you requested . Please also provide a written response to our most recent drainage study , commenting on the acceptability of the structure , pond, detention, pond outflows, and hydraulic/hydrologic models. Please also tell us if a CLO MR and/or LOMR will be required for it. ·~ ENGINEERS • PLANNERS• SURVEYORS A Sub si diary Firm of Southwest Planning and Design, Inc. 1601 E. Lamar Blvd .• Suite 200 •Arlington , Texas 76011 817 /548 -0696 • Metro 265-8836 • Fax 817 /265-8532 Mr. JejfTondre City of College Station October 18, 1999 Page Two Thank you for your timely response to these issues. If you have any questions, please call me at (817) 548-0696. ~ry~ Ron King, P .E. cc: Mr. Mark Smith, Director of Public Works Ms. Natalie Ruiz, Development Coordinator F :\ WORD\COLLEGE\215\ltr.Tondre.clarification. wpd •. February 18, 1998 College Station I.S.D. Construction Services 1812 Welsh Street College Station, TX 77840 Attn: Mr. Bill Savage, P.E. CHEATHAM AND ASSOCIATES Re: 1019-210, College Station I.S.D. Jr. High Detention Pond Analysis In accordance with your request, we studied the capacity of the existing detention pond at the College Station Jr. High site. The site was surveyed and found to be not in compliance with the Drainage Report for Lot IR, Block 1 (27.744 Acres) Westchester Park-Phase One Junior High School July, 1989 prepared by Kling Engineering and Surveying 4101 Texas Avenue Bryan, Texas 77803 We have prepared a new site grading plan, sheet 1 of 1, and a computation chart depicting storage that will be created when the site is constructed. As indicated, the new plan will proved more storage than originally designed. I, Eddie Cheatham, P .E., do certify that the design enclosed provides more storage capacity than the original design for the detention pond located at the College Station Jr. High School campus. (See computation chart.) Eddie Cheatham, P .E. cc: /Paul Kaspar, P .E. City of College Station ENGINEERS• PLANNERS• SURVEYORS A Subsidiary Firm of Southwest Planning and Design, Inc. 1601 E. Lamar Blvd.• Suite 200 •Arlington, Texas 76011 817 /548-0696 • Metro 265-8836 • Fax 817 /265-8532 COLLEGE STATION October 26, 1999 Mr. Ron King, P.E. Cheatham & Associates 1601 E Lamar Blvd . Suite 200 Arlington, TX 76011 P. 0 . Box 9960 Re: A&M Consolidated Middle School Detention Facility Mr. King, 1101 Texas Avenue Tet. 409 764 3500 Colle ge Stati on , TX 77842 This is in response to your letter of October 18, 1999, for the above-mentioned project. I have reviewed the detention pond submittal on October 8, 1999. The configuration submitted is intended to address the increase in runoff as a result of the school expansion . This pond is designed with a top of berm elevation of302' msl, reduces peak 100-year flows from 648 cfs to 643 cfs, and results in a maximum 100-year water surface elevation of 300.4'. Based upon the hydro logic analysis, this design is acceptable to meet the needs of CSISD. Embankment and riprap specifications should be included within the plans to complete the submittal. As noted in this report, a FEMA conditional letter of map revision is required as a result of this construction . The City of College Station desires for this pond to be expanded to further reduce the peak flow below the existing conditions. The city's Drainage Policy and Design Standards require 0.5 feet of free board (page 74). Based upon this, we would like to optimize the pond with a maximum water surface elevation of 303.5 for the 100-year storm. The outlet structure should be modified and the pond optimized, as needed, to produce this maximum water surface. All other design storm flows should be calculated based upon this outlet, provided the maximum discharge for any storm event is not increased. We do not wish to set target discharge or volume, but optimize it based upon site limitations. Any additional excavation should be limited to that necessary to balance the cut and fill with regard to the dam embankment. All additional excavation should be outside the jurisdictional waters to eliminate the need for a 404 individual permit. We will coordinate with TxDOT and Texas A&M regarding any increases in water surface elevation not located on CSISD property. We will request~ map showing the location and magnitude of the increases on adjacent properties . George Bush Drive is already overtopped by the l 00-year design storm and acts as a long weir. Because of this, we expect that the impact upstream will be minimal. Please advise us if this is not the case, or if you see any other problems, which may arise from this configuration. Either pond configuration will require a CLOMR and LOMR and the city will forward the applications to FEMA with a positive recommendation . Home of Texas A&M University Enclosed please find a copy of a preliminary hydrologic model fo r the pond with th e maximum 100-year water surface elevation set near 303.5 . This model uses av-notch weir with an angle of 38 degrees . This model shows that that configuration is capable of reducing the peak 100-year peak flow at Anderson Drive to approximately 590 cfs, an approximate 10% reduction in flows . At your discretion, you may choose to raise the top-of-berm, or the center portion, to 304.5 to provide one foot of free broad. All detention pond configurations must be coordinated with Municipal Design Group , which is designing the new parking lot for the Justice of the Peace office. If you have any questions, or need further information, please call me at (409) 764-3570 . Sincerely, ~(~ Jeff Tondre, P.E. Acting Asst. City Engineer Cc: Mark Smith, P.E., Director of Public Works W.J. Savage, Construction Manager, CSISD Via fax: (409) 694-5612 College Station Independent School District June 8 , 1998 Mr. Paul Kaspar City of College Station P . 0 . Box 9960 'E:(ceiknce. In Uucation ... JW. Investment In 'I1ie !Future. Letter No . 663 College Station , Texas 77842-9960 Subject: College Station Junior High School Detention Pond Corrective Construction Work Dear Mr. Kaspar: The construction work designed by Cheatham & Associates to add additional capacity to the detention pond of subject school has been completed . We required that the contractor pre-stake the pond prior to construction and to leave all stakes in place such that we could verify that the grading was performed to the design . Upon completion of the construction work the contractor and I examined each stake to verify that the excavation and dike construction met the specified requirements . From a personal inspection as stated above I certify that the excavation was constructed to or below the required grade elevation~>, the berms were constructed to or slightly above the specified elevations and all grades were uniformly straight between grade stakes . This detention pond meets the design impoundment requirements specified on the drawings. Please advise if this is acceptable with the City. We will hydromulch this entire basin following your notification. Y ours t ru!y , WJS/b cc : D. Nea l G . Mclean File LIP Construction Services 1812 Welsh Street College Station, TX 77840 409-694-5610 FAX 409-694-5612 JIM SCALES, Ph.D. Superintendent of Schools COLLEGE STATION P 0 . Bo x 9960 November 11, 1997 Mr. Bill Savage, P.E. College Station Independent School District Maintenance and Operations 2000 Welsh Ave. College Station, Texas 77840 Dear Mr. Savage: 1101 Te xas Avenu e Tel : 409 764 3500 Co ll ege St at ion , TX 77842 I am writing this letter to document our conversation on Friday November 7, 1997 regarding fill within the detention facility at the Rock Prairie Junior High School. It is my understanding that CSISD is aware of the possible impacts of decreasing the detention capacity of the basin and the potential impacts to downstream properties and is currently seeking a sound engineered solution to the problem . In our phone conversation you outlined a rough time schedule by which CSISD would come into compliance with the City of College Station's Drainage Ordinance . • Grading of existing fill within the detention facility (November 7-11) • Topographic-survey of re-graded detention facility (November 11-12) • Forward topographic survey to Cheatham & Associates for detention pond re-design (November 17) • Cheatham & Associates'. re-design of pond and outlet structure submitted to City for review (December 8) Please keep me informed of the progress on this project and don't hesitate to call if you have any questions. Sincerely, /1;~ W . Paul Kaspar Graduate Engineer xc: !/'Development Permit Fil # 387 Veronica Morgan, Assista c· Jon Mies, Code Enforcement Home of Texas A&M University TO: CITY OF COLLEGE STATIO DF:VELOPME T SERVICES 1100 Tl!~XAS AVENUE COL LKGF. ST ATION , TEXAS 77840 TPM. Total Program Managcmc~t , Inc , TRANSMITTAL LETTER PROJECT: JUNIOR HIGH SCHOOL ATHLETIC COMPLEX COLLEGE ST A TION l.S ,D, ATT 1 : SHIRLEY VOLK PROJECT NO: Bond DATE: 30 JULY 1996 We arc send in g you [ x ] Att ached [ ] U nde r se parate cove r Via. __________________________ t.he fo ll owin g ite ms : ] D rawin gs ] S pecifi ca tio ns COPIES DAT E I ] Co py of Lett e r [ J Shop Drawin g s [ ] Change Orde r []Sa mpl e s [ ] P rint [ ] Re p ro duc ibl es . [ x ] DEVELOPME T PERMIT DESCRIPTION .HJ LY 23 , 1996 DEVELOPME T PERMIT FOR CSISD C OLLEGE STA TIO J UN IOR HJ G H SCHOOL SITE IMPROVEMENTS. THESE ARE T RA 'SM ITrED AS C HEC KED BELOW: [ ] For App ro val [ ] No Exceptio n Taken A s Submitted [ ] Res u bmit. ____ Co pi es for Approval [ X J Fo r Yo ur ll sG [ ] Ex ce pli on Ta ken As oted [ ] S ubmit Co pi es fo r Distributio n [ ] As Requ e sted [ J Rejec ted Resubmittal Required [ ] Return Co rrected Pri nts REMARKS: COPJES TO : F ILE 128 E. Tex as St. Grapevin e, Texas 7605 1 (8 17) 4 88-77 32 fax(8 I 7) 488-9708 18 12 Welsh, ste. I 30C Coll ege Stati o n, Texas 77840 (409) 693-5650 fax( 409) 693-6996 163 S. Main , ste. A Kell er, Tex as 76248 (8 17)43 1-11 29 fax(8 I 7) 43 1-1583 55 11 Park crest Dr. #20 7 Austin , Texas 7873 1 (5 12) 454-25 80 fax(5 I 2) 454-263 0 .. . ·-4o. Figure XII Development Permit City of College Station, Texas College Station Junior High 24.744 Acres Crawford Burnett Site Legal Description : League, A-7 & Robert Stevenson League, A-54 SiteOwner: College Station I.S.D. Address : 1812 Welsh, College Station, TX 77840 Tclephone: 409/693-5650 Architect/ Address : 1601 E. Lamar Blvd., #200, Arl., TX Engineer : Cheatham & Associates Tel e phone No : 817 /548-0696 76011 A ..J..J .----· r..uu1 c ::.~. ------------- Telephone No : _________ _ Date Applicati o n Filed : ________ _ Approved : ___________ ~ Application is hereby made for the following development specific waterway alterations : Enlarge existing detention pon_~L. 0 Application Fee 0 Signed Certifications 0 Drainage and erosion control plan, with supporting Drainage Report two (2) copies each . 0 Site and Construction Plans, with supporting Drainage Report two (2) copies each. 0 Other: -----------------------------~-~ ACKNOWLEDGMENTS : L College Station I.S.D. , design engineer/owner, hereby acknowledge or affirm that : The information and conclusions contained in the above plans and supporting documents compl y with the current requirements of the City of College Station, Texas City Code, Chapter 13 and its associated Drainage Policy and Design Standards . As a condition of approval of this permit application , I agree to construct the improvements proposed in this application according to these documents and the requirements of Chapter 13 of t College Station City Code. Contractor Figure XII Continued CER TIFICA TIO NS : (for proposed alterat ions within designated flood hazard areas .) A. I , certify that any nonresidential structure on or proposed to be on this site as part of this application is designated to prevent damage to the structure or its contents as a result of flooding from the 100 year storm . c .... 9 ;t ~, --Engineer Date I3 . I, ce rtify that th e fi ni s he d floor eleva tion of the lowest floor , including any basement, of any residential structure , proposed as part of this application is at or abov e the bas e flood eievation estab(i sh ed ir. the lat e st Federal Insurance AdrTu.nistrat~on Flood Hazard Stud y and maps , as amended . -Engineer Date C . I, ce rtify that the alterations or development covered by this permit shall not diminish the flood -carrying capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent with requirements of the City of College Station City Code, Chapter 13 concerning encroachments of floodways and of floodway fringes . Eng ineer Date I , do certify that the proposed alterations do not raise the le ve l of th e 100 year flo o d above elevation established in the latest Federal Insurance Administration Flood Hazard Stud y. _1u : , . Cv ... _.. . ~ En g ineer Dat e C onditions or comments as part of appro va l:-------------------- In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities . I hereby grant this permit for development. All development shall be in accordance with the plans and sp ecifications 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 .