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HomeMy WebLinkAboutSW8021031_COMPLIANCE_20030113STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021031.WK1 PROJECT #: SW8 021031 REVIEWER: L. Lewis PROJECT NAME: Joe & Moe's Auto Services Site DATE: 13-Jan-03 Receiving Stream: Shailotte River Class: C SW Drainage Basin: Lumber Index No. LBR59 15-25-2-15-(1) Site Area 2.19 acres Drainage Area 722$. 00 square feet Area = 1.70 acres IMPERVIOUS AREAS Building Parking SW TOTAL SURFACE AREA CALCULATION IMPERVIOUS 67.55% Des. Depth 5 TSS: 90 7500,00 square feet 40238.00 square feet 2405.00 square feet square feet square feet square feet 5014:3 C10' square feet SAIDA Ratio Req. SA Prov. SA Rational C Rational Cc= 4.83% 3584 sf X. sf VOLUME CALCULATION " place a "1" in the box if Rational is used Rational ?* Des. Storm :......1.'DO _.. inches Rv= 0.66 Bottom 4 msl Perm. Pool 9':Q(n msl Design Pool 10.25 msI Design SA 4770 sf Req. Volume 407fJ cf Prov. Volume xx- cf ORIFICE CALCULATION Avg. Head = Flow Q2, cfs Flow Q5, cfs No. of Orifices Diameter, inches Drawdown = 0.60 ft 0.024 cfs 0.009 cfs weir HxW days FOREBAY Perm. Pool Volume= Req. Forebay Volume= Provided Volume= Percent= SA @ _ Elevation= 5385 1077 1088.00 Q2 Area = 0.91 sq. in. Q5 Area = 0.36 sq. in. Orifice Area 0.79 sq. in. Q= 0.020 cfs i n x FTU COMMENTS Surface Area , Volume and Orifice are within Design Guidelines in M JOE & MOE'S AUTO SERVICES, INS-a0� SHALLOTTE, NC STORMWATER DESIGN CALCULATIONS FOR SITE DEVELOPMENT May 2002 Prepared by: East Coast Engineering Company, P.A. Consulting Engineers Shallotte, North Carolina 28459 Post Office Box 2469 4918 Main Street Office: 910.754.8029 r O U cn m W C 6L 0 U. 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V � Y" m _ $ ,� +: ,E .. ` Y Y+ Q� co L Otl Wcl W q) O O co co .O Z - +— ro CL p N Q) cC I O -0 -0 O C A 4 Q r-LO m Cl)¢ m b t p 41 q) O _ co m (p co y b b� b U -� c o\°\° co Q Q 'b b Cn o Q F` m a co Q y > L a��i coo Cn c6 Ycvs,O w �, Z30- U o o �ZEZ nw �n oc z a Cr �o� ro Q �QQ Q�� dL� V)w c cy �§ § 0 § ci 6 00 ° Q b § \ 7 / \ o o _ \ E \§kk\k/ \7 E / � § °®Im Sƒ 2 E k§; g f @2\��kkE2f�f c c m g a a q u]§ d\ q k f \ k CL o � ja § § f § B § § (D w § f \ Lr) H a R § 2 U < E z Cl) - cc < / ) } \ § - E / 4/ 4\ a 0 It \ %t ) cn § \ & ±f< (b \ \ k _ \ k Joe and Moe's Auto Repair Service, Inc. Forebav Calculations TOTAL POND VOLUME at PERMANENT POOL East Coast Engineering Company, PA SMH FT MSL) AREA (SF) VOLUME (CF) VOLUME (CF) 4 78 169 169 6 544 731 1303 7 919 1302 2604 8 1685 2257 4861 20% OF PERMANENT POOL VOLUME = 972.253 Surface area at Permanent Pool @ 9 3602 Surface area at Storage Pool @ 10.25 5014 Total storage volume provided 5385 cf FOREBAY VOLUME at PERMANENT POOL ELEVATION SURFACE INCREMENTAL ACCUMULATIVE (FT MSL) AREA (SF) VOLUME CF VOLUME (CF) 6 95 163 163 7 231 345 508 1 Sheet 3 kI 62 n ¢ \ LU \ 0 ) 0: § 2 �_j �w &6 \q \� LU� o r f n \ 22 \m /� 7� K Q\ 2 / \ ƒ E % \ \ \ � ® 2 \ / / \ d 6 c m o � m2 U E \ g 9 ¥ 0) a R / 2 o Q O / \ / : K _ - o � / k w � k % b ƒ LU i w w � \ \ / w LLJ Cl) ® ® \ w w z / z 7 \ § A o @ w / k -j 0 ® m > / � z D 2 7LL e z ± w I_ - 6 w = u O n w 2 < / _m \ \ ƒ 3 ® E O f ,It k m 7 W 742 7130' o 001 73B 25' 3y 218C 000 FEET 1765 C rJ r) r:, socc Lj ' ( - FEET 7 ; I � 'u J! fl, 7 �)34&1 -39 A 130, r so 'A Radio, CL er ;no "WIN 'I BTUnswlc Gri(✓ e"Qh 4w mot �A un pl cu'r t 4, mes' h Y s 0 -g'- r,fl Masonic -AO a I I nt1pe TOY—w r s h i xl_ 4 L79 V rtOn . - rA Y 52 A NJ IR Chur Go 0 m B bun d I f Peasant Hill .0 33 57' 30" 760 3759 NARRATIVE for Joe & Moe's Auto Services, Inc. Shallotte, Brunswick County, NC .DESCRIPTION The site is a 2.19-acre tract located in Shallotte, NC, at 5651 Main Street. The proposed development on the site is a commercial development consisting of an auto service center with adjacent parking and display area. The project is an expansion of the existing business on the site. The site has an existing garage and a gravel circle drive with an asphalt entryway from Business Hwy 17. A 1.70-acre section of the site will be disturbed and graded to accommodate the proposed plans. Construction is scheduled to begin as soon as all permits and approvals are obtained. STORMWATER MEASURES The stormwater runoff from the site is estimated using the rational method. The site is located near the origins of the Shallotte River and classified as C-Sw, HQW waters. The first inch (1.0") of rainfall is accounted for in the design. The stormwater will collect into one (1) wet detention basin (pond) on the site. The pond is designed so the 25-year storm event, using rainfall data for the area, will not overflow the available freeboard. The stormwater run-off will be directed to the pond by proper grading of the asphalt paving and curbing around the perimeter of the parking and driveways. No pretreatment device is designed for the pond other than the proposed forebay. EROSION CONTROL MEASURES The perimeter of the project area will be protected from erosion and sedimentation runoff with silt fencing. Vegetation will be established quickly in the disturbed areas not to be paved after the initial grading activities have concluded. Excelsion matting will be used as necessary to eliminate soil erosion. The 'grading contractor and the developer will provide the maintenance for the erosion control measures. CONSTRUCTION SEQUENCE The Contractor will install silt fence prior to beginning any clearing and grading operations. The wet detention basin will be constructed immediately after that portion of the site is graded, and the outlet structure will be installed. The disturbed areas will be landscaped and seeded upon completion, and as soon as possible. The building will be constructed and the paving will be installed as per the design plans. The wet detention basin will be restored to design depth after completion of all other construction.