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HomeMy WebLinkAbout73 Development Permit 648 St Matthews Baptist ChurchDEVELOPMENT PERMIT PERMIT NO. 648 ST. MATI1IEWS BAPTIST CHURCH FOR AREAS OUfSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CI'IY CODE SITE LEGAL DESCRIPTION: SITE ADDRESS: HRDLICKA SUBDIVISION, LOT 9&10 BLOCK 3 409 HOLLEMAN DRIVE OWNER: Thomas A Hall 409 Holleman Drive College Station, TX 77840 (409) 775--0771 DRAINAGE BASIN: Bee Creek Trib B TYPE OF DEVELOPMENT: SITE CONSTRUCTION AS PER APPROVED PLANS OF MAY 28, 1999. The required irrigation system is to be installed and operational concurrent with the completion and opening of the parking lot The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work. Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced before any operations of this permit can begin. 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. 5-ZX-rJ Date Owner/ Agent Date Contractor Date DRAINAGE COMPUTATIONS For Saint Matthew's Baptist Church 0.5 Acres Tract College Station , Brazos County, Texas Prepared for St. Matthew's Baptist Church 409 Holleman Drive College Station, Texas 77840 Telephone: (409) 775-0771 Prepared by: Garrett Engineering 4444 Carter Creek Parkway -Suite 108 Bryan , Texas 77802 Telephone: (409) 846-2688 Garret! Er0.-ln0-'4"'44 Cartet <:reek Palllwoy Suite 10ll-&}an, Toxas nso7-Teiephono; (409) 846-2688 -Fax: (409) 846-3094 -Page 1 J Drainage Computations fora Site & Grading Plan for St. Matthew's Baptist Church College Station, Brazos County, Texas *February,1999* Summary The project consist of a 0.50 acre tract situated at 409 Holleman Drive. The 0.50 acre tract currently is being used as a church; zoned Residential District. A 0.19 acre parking area, currently gravel, are the proposed developments. See Exhibit "A" -Site Plan. The total drainage area tributary to the project is 0.50 acres. The pre-development run-off coefficient for the 0.50 acre tract was estimated to be 0.46 , while talcing into account specific site improvements depicted on Exhibit "A" would result in a post-development weighted run-off coefficient of0.'7. The report calculations are summarized according to the following methodology. Beginning on page 2, based on the total tributary drainage area of the project (being estimated at 0.50 acres), the pre-development run-off coefficient (calculated at 0 :4~, and a minimum time concentration of 10 minutes, the relative pre-development peak discharge rate ("Q") was determined. The Rational Method was utilized to compute the estimated peak pre-development discharge rates. The equation that represents the Rational Method is as follows: Q =CIA. "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off coefficient, "I" is the storm intensity in inches per hour, and "A" is the area of the drainage basin in acres. Computations on page 3 are based on the tributary area of0.50 acres, the post- development run-off coefficient ofO.bl(being weighted according to the re lative amo unts of pervious and impervious surface assert), a minimum t ime of concentration o f 10 minutes, to yield the relative pre-development peak discharge rate ("Q") (assuming the same minimum time of concentration of 10 minutes). The Rational Method was again utilized to compute the estimated peak post-development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA, where; "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off coefficient (in the post- development condition "C" is weighted at 0.1..1), "I" is the storm intensity in inches per hour, and "A" is the area of the drainage basin in acres. Comparison of the peak pre-development vs. post-development discharge rate is determined as the volume difference generated between the pre-development and post- development hydrographs. Comparison of the pre-development vs. post-development peak discharge rates reflect a minimal impact in discharge rate . .Detem1ine Totaf Pre-Development Peak Ste>fm Water Discharge R$tes Tributary Area C'A"): 0.50 Acres Pervious Area : 0.37 Acres Impervious Area : 0.13 Acres Run-Off Coefficient ("Cwtj : 0.46 Time Of Concentration ("T/c"): Woodlands: Low Elevation: High Elevation: Distance (Feet): Slope(% Grade): Velocity ("Vw"): Time: Pastures: Low Elevation : High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vp'): Time: Pavements: Low Elevation : High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vpave'): Time : Total Travel Time: Hourly Intensity Rates ("I"): 2-Year. 6 .33 5-Year: 7.69 10-Year: 8 .63 25-Year: 9.86 50-Year: 11.15 100-Year: 11 .64 Peak Discharge Rate ("Q"): 2-Year. 1.44 5-Year: 1.75 10-Year. 1.97 25-Year: 2.25 50-Year: 2.54 100-Year. 2.65 c = 0.30 c = 0.90 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 10.00 Minutes Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second • Determine Post Development Peak Storm Water Discharge Tributary Area ("A''): 0.50 Acres Pervious Area: 0.19 Acres c = 0.30 c = 0.90 Impervious Area : 0.31 Acres Run-Off Coefficient ('cwt•): 0.67 Time Of Concentration ("T/c"): 10 Minutes Hourly Intensity Rates ("I"): 2-Year: 5-Year: 10-Year: 25-Year: 50-Year: 100-Year: Peak Discharge Rate C'Q"): 2-Year: 5-Year: 10-Year: 25-Year: 50-Year: 100-Year: Comparison Of Predevelopment And Current Peak Discharge Rates . Predevelopment 2-Year: 1.44 Ft3/sec 5-Year: 1.75 Ft3/sec 10-Year. 1.97 Ft3/sec 25-Year: 2 .25 Ft3/sec 50-Year: 2.54 Ft3/sec 100-Year: 2 .65 Ft3/sec 6 .33 Inches I Hour 7.69 Inches I Hour 8.63 Inches I Hour 9.86 Inches I Hour 11 .15 Inches I Hour 11.64 Inches I Hour 2.13 Cubic Feet I Second 2.58 Cubic Feet I Second 2.90 Cubic Feet I Second 3.31 Cubic Feet I Second 3.75 Cubic Feet I Second 3.91 Cubic Feet I Second Current Increase 2.13 Ft3/sec 0.68 Ft3/sec 2 .58 Ft3/sec 0.83 Ft3/sec 2.90 Ft3/sec 0 .93 Ft3/sec 3.31 Ft3/sec 1.07 Ft3/sec 3.75 Ft3/sec 1.20 Ft3/sec 3.91 Ft3/sec 1 .26 Ft3/sec 16:03 '5'409 76-l 3496 DEVELOP~IE N T SVCS ......... GARRETT [4Joo2 :0~ SUPPLEMENT.AL DEVELOPMENT PERMIT INFORMATION Application is hereby made for the following development specific waterway alterations : ~ fJ..~.v34S~~ f"Dt..~~~L.ol. 1~<cu.i::::e:; ~ LANt:?Xe§f?iNry I q,C:~PI~ I r\Nb \~esnoN ~· ACKNOWLEDGMENTS: I , .:::..-r: AA~ BA:~ L.J~. design engineer/owner, hereby acknowledge or affirm that: Th e information and conclusions contained in the above plans and supporting documents comply \ltith the CUJTent requirem ents 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 pemtlt application, I agree to construct the improvements proposed in this application according to ~and J _e ~f Chapter 13 of the College Station City Code . 'j. 0T1n1111/z f\v s att,_[.sr <PbteJL~=-- P10peny Owner(s) Contractor CERTIFICATIONS: (for proposed alterations withi n 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 . Engineer Date B. I. , certify that the finished floor elevation of the lowest floor, including any basement, of any residential structwe, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps , as amended. Engineer Date c. I, . certify tlui.t the alterations or development covered by this permit shall not diminish the flood~ng capacity of the waterway adjoining or crossing this pennitted site and tl'iat such alterations or development are consistent with requirements of the City of College Station Ciiy Code. Chapter 13 concerning encroachme nts of flOodways and of floodway fiinges . Engineer Date D. I, , do certify that the proposed alterations do not raise the level oft11e 100 vear flood above elevation established in the latest Federal Insurance Administration Flood Hazard Study . • Engineer Date Co.nditions or comments as part of approval : In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to i nsure that debris from construction, erosion, a.nd sedimentation shall not be deposited in city streets , or existing drainage facilities . I hereby grant this pennit for development. Alt development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project . AH of the applicable codes and ordinances of the City of College Station shall apply . SITE PL;U.; Al'PLICATh)N SITEAPP 04 /13 /99 , I ot~3 GARRETT ENGINEERING ,• COllSUL TillG £HG1NURlltG & LANO SURVfYING 4444 CARTlR CREEK PARKWAY. SUITE 111 ·BRYAN, TEXAS 771112. (4111) I~ • {411) 141-l014 TO: RE: We Are Sentling You : __ Herewith _ Untlcr Scpnrme Cover The Following: Copies _l Remn.rks: By: cc: Date Description lk··:~o ~[E © fE G \'ll fE \\fil APR 3 0 1 By ~,Ju Rccci\'l'tl Dy:------------