The URL can be used to link to this page

Home My WebLink AboutSW8021025_COMPLIANCE_20030114STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW�D, - DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE COMPLIANCE EVALUATION INSPECTION DOC DATE�� YYYYMM DD Beach Assembly of God Forebay Calculations East Coast Engineering Company, PA DFC TOTAL POND VOLUME at PERMANENT POOL 5' depth, 6:1 slope for 10 ', then 3:1 slope ELEVATION (FT MSL SURFACE AREA (SF) INCREMENTAL VOLUME CF ACCUMULATIVE VOLUME (CF) 31 433 686 686 32 939 1547 2233 33 2154 2593 4825 34 3031 3780 8605 35 4528 5541 14145 36 6553 227vf SO-1 3 20% OF PERMANENT POOL VOLUME = 2829.000 FOREBAY VOLUME at PERMANENT POOL 2:1 slope ELEVATION FT MSL) SURFACE AREA (SF) INCREMENTAL VOLUME CF) ACCUMULATIVE VOLUME (CF) 33 637 751 751 34 864 991 1741 35 1117 1255 2996 36 1393 t Sl c'l rp Jr AL IRTVi— Aso RECEIVED JAN 14 2003 DWQ PROD' # O2 /Oz5 Revision 10/9/02 Q U a LL a; C O U C C LU O U y ro LU m (4 U Gco OO Q 19 �_ O L L L n h V O 0 4— U) L . U) 4— U) 4— U L . U) �� Ul 4 - U 4'^ U) 4. U 4— U 4— U U U .0 U I- 1- Ln O m r O I,- CD M LO w Imo. I,- I~ m tD m to O (D GD CD CD (M M O O LO a M O GO CD q O m GO N (D CDto}T W T r T f• O(n 4n (f) of Nt — N GOO CA O0O T O I-- �- CD O O i` O C?r- 00 CD tC) CV O O00) CD hO C7Go0O '1 NCV OO C7co6 O N O � �• 4i CD Q CL5 0 p 0 x N U) O 4 x -p t1 N O D CL x > a r r �- _� L x x (D T XCO�? cn N) 7 7 Q) CL r II j v 7 m 4f) II n o Q C > Q N ro ro LO r. cm c .( �- Q ❑ + r W CV Cn 0 U) 0 i N �� N E CZ m K U) II Omo C R) 4_ O m � - -G - C X UU X y v Q cz'II v` (n L L {j E C j C C r U7 V II Q It I! II II as 0 �rY>O D O S ¢t U ¢ Q 4 4 p CD n, — b C, (D a mm i CV LO U vy U II II 0 m m 0 O m 0 +. C C 6d O O oro.o�-- ab�� ao IML o 11L ti c� From°' ��It 5 a� 3 °° as co I� m (aj ro m� a C m rom L O? ¢ S 3 m ces c °�) mo a r r m o �'-. vej y acx m y' 4- O c N m b N N a�a, Hsu) roa ro� 2 m ro �.. O �a� m m s�o(D o m m C)m m in ro a m a� mUm6aamm o a > m m 7 i ro ro cp a cU -Q m CN C O O .0 ¢¢ O O CL � � �� 4vali� OC1U2 U SOU 13 Q ID Qtiti OL C'1 W�� L Q DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021025.WK1 PROJECT NAME: Beach Assembly of God DATE: 10-Jan-03 Receiving Stream: Shallotte River Class: C Sw HQW Drainage Basin: Lumber Index No. LBR59 15-25-2-(1) Site Area 5.50 acres Drainage Area 4 2877 QO square feet Area = 4.80 acres IMPERVIOUS AREAS Rational C Building 16117.00 square feet Parking 69696.00 square feet Sidewalks 4792.00 square feet square feet square feet square feet TOTAL 9060'; square feet Rational Cc= 0.11 SURFACE AREA CALCULATION % IMPERVIOUS 43.38% Des. Depth 5 TSS: 90 SAIDA Ratio 3.04% Req. SA 6342 sf Prov. SA ...:.:::...:: ;.:$� .3 < sf VOLUME CALCULATION ' place a "'I" in the box if Rational is used Rational ?* FOREBAY Des. Storm 1:,04> inches Perm. Pool Volume = 14145 Rv= 0.44 Req. Forebay Volume= 2829 Bottom 31 msl Provided Volume= 2996.00 Perm. Pool :0€ msl Percent=2°4' Design Pool 37.17 msl Design SA 8073 sf Req. Volume 766 cf Prov. Volume cf ORIFICE CALCULATION SA @ _ Elevation= Avg. Head = 0.56 ft Q2 Area = 1.77 sq. in. Flow Q2, cfs 0.044 cfs Q5 Area = 0.71 sq. in. Flow Q5, cfs 0.018 cfs Orifice Area 0.79 sq. in. No. of Orifices :::'7:' Q= 0.020 cfs Diameter, inches 1.. weir H x W , ..:,, , :> in x :......:.: .:..: in Drawdown = ..:`....... _ days COMMENTS Surface Area , Volume and Orifice are within Design Guidelines 4 NARRATIVE RECEIVED for OCT 2 2 2002 Beach Assembly of God Brunswick County, NC DWQ DESCRIPTION PROJ # _ ..,.. The project area is 5.08 acres of the total 5.41-acre site located in Brunswick County, NC, near Grissettown. It is located on the west side of US Highway 17 about '/4 mile north of the intersection with NC Highway 904. The proposed development on the site is a church with associated paved drive and onsite parking. The site is cleared with sandy topsoil and grades ranging from 0.5% to 2.0%. The site will be graded to accommodate the proposed development. Construction is scheduled to begin as soon as all permits and approvals are obtained. STORMWATER MEASURES The stormwater will be treated with low -density stormwater features. The total proposed impervious area constitutes 43% of the disturbed area. The stormwater runoff from the site was estimated using the rational method for a 25-year event using published historical rainfall data for the area. The stormwater run-off from the impervious surface will be directed to the onsite pond by overland flow. The stormwater will flow through ten (10) curb cuts located along the periphery of the parking lot into two grassed swales located on either side of the impervious surface. The swales will route the stormwater to a wet detention basin utilizing a vegetated littoral shelve to accomplish water quality treatment of storm drainage. Discharge from the pond will be to an existing off -site ditch. A small portion of the lot will continue to drain to the existing NCDOT right -of way. EROSION CONTROL MEASURES The perimeter of the project boundary will bE fencing. Vegetation will be established quickly in detention basins. Excelsior erosion protection will be eliminate soil erosion. The grading contractor and maintenance for the erosion control measures. CONSTRUCTION SEQUENCE protected from erosion with silt the swales and around the wet used temporarily in the swales to the developer will provide the The Contractor will install silt fence prior to beginning any clearing and grading operations. The wet detention basins will be constructed and runoff will be directed to the basins during grading operation of the lots and the swales. The roadway will be rough graded. The swales will be established and protected with excelsior. The water and sewer utilities will be installed. The storm drainage features will be installed and inlet protection will be established. The disturbed areas will be landscaped and seeded upon completion, and as soon as possible. The wet detention basin will be restored to design specifications after completion of all other construction.