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Home My WebLink AboutSW6221201_Supplement-EZ Form_20230731I FORMS LOADED FORMS LOADED x0k "it Z: .4x SEAL 032721 I N o Designer Date 2-c) DRAINAGE AREAS ............................................................................................................................................................................................................................................................................. 1 Is this a hi h densi roject? Yes 2 If so, number of drainage areas/SCMs 1 3 Does this have low density areas No 4 „pro)ect If so number of low density drainage areas 0 Is all/part of this project subject to previous rule 5 versions? No FaEn5LgAP.Fp. DRAINAGE AREA INFORMATION Entire Site 1 4 Type of SCM Wet Pond 5 Total drainage area (sq ft 269,201 202,525 6 Onsite drainage area (sq ft 269,201 202,525 7 Offsite draina a areas ft 0 0 8 Total BUA in roject (sq ft 170952 sf 170952 sf New BUA on subdivided lots (subject to 9 permitting) (sq ft) n/a n/a,,,.. New BUA not on subdivided lots (subject to 10 permitting) (sf) 170952 sf 170952 sf 11 Offsite BUA (sq ft) 12 Breakdown of new BUA not on subdivided lots: Parking„ (sq ft) 65074 sf 65074 sf Sidewalk (sq ft) 925 sf 925 sf Roof (sq ft) 104953 sf 104953 sf Roadway (sq ft) Future..(sq ft) Other, please specify in the comment box below (sq ft New infiltrating permeable pavement on 13 subdivided lots (sq ft) New infiltrating permeable pavement not on 14 subdivided lots (sq ft Existing BUA that will remain (not subject to 15 permitting) (sq ft) 16 Existing BUA that is already„permitted (sq ft) 17 Existing BUA that will be removed (sq ft) 13016 sf„ 13016 sf 18 Percent BUA 19 Design storm (inches) 1.0 in 20 Design volume of SCM (cu ft) 21695 cf 21 Calculation method for design volume Simple Method ADDITIONAL INFORMATION �Please use this space to provide any additional information about the 22 drainage a rea(s) Drainage area for pre -post development analysis is the drainage area to the proposed wet pond. The existing drainage patterns do not change with respect to the site drainage outfall (lowest point on property). All new impervious will drain to wetpond; remaining area on property that does not d"resin to Mdet nend mM&I Mm ain nendO W 1............................................................................................................................................................................................................................................................ WET POND 1 Drainage area number 1 2 Minimum required treatment volume �cu ft� 13651 cf GENERAL MDC FROM 0211.1050 O50 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes .......................................................................................................................................................................................................................................................................................................................... 4 Is the SCM located away from contaminated soils? Yes .......................................................................................................................................................................................................................................................................................................................... 5 What are the side slopes of the SCM (H:V)? 3:1 .......................................................................................................................................................................................................................................................................................................................... 6 Does the SCM have retaining walls, gabion walls or other No engineered side slopes? 7 Are the inlets, outlets, and receiving stream protected from erosion Yes 10- ear storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes design volume? 9 .......................................................................................................................................................................................................................................................................................................................... What is the method for dewatering the SCM for maintenance? Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC (8)? Yes .......................................................................................................................................................................................................................................................................................................................... 12 Does the drainage easement comply with General MDC (9)? Yes .......................................................................................................................................................................................................................................................................................................................... 13 If the SCM is on a single family lot, does (will?) the plat comply with N/A General MDC 10 ? 14 Is there an O&M Agreement that complies with General MDC (11)? Yes 15 Is there an O&M Plan that complies with General MDC (12) . Yes 16 Does the SCM follow the device specific MDC. Yes 17 Was the SCM desi ned b an NC licensed rofessional . 9 R Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA 19 Has a stage/storage table been provided in the calculations? Yes 20 Elevation of the excavated main pool depth (bottom of sediment 183.00 removal) (fmsl) 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 185.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 191.00 23 Elevation of the permanent pool (fmsl) 192.00 24 Elevation of the top of the vegetated shelf (fmsl) 193.00 25 Elevation of the temporary pool (fmsl) 193.70 26 Surface area of the main permanent pool (square feet) 7810 27 Volume of the main permanent pool (cubic feet) 21695 cf 28 Average depth of the main pool (feet) 4.00 ft 29 Average depth equation used Equation 3 30 If using equation 3, main pool perimeter (feet) 560.1 ft 31 If using equation 3, width of submerged veg. shelf (feet) 6.0 ft 32 Volume of the forebay (cubic feet) 3987 cf 33 Is this 15-20% of the volume in the main pool? Yes 34 Clean -out depth for forebay (inches) 54 in 35 Design volume of SCM (cu ft) 21695 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice, orifice diameter (inches) 2.0 in 38 ....If weir, weir height(inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.18 41 Are the inlet(s) and outlet located in a manner that avoids short- Yes circuiting? 42 Are berms or baffles provided to improve the flow path? No 43 Depth of forebay at entrance (inches) 60 in 44 Depth of forebay at exit (inches) 12 in 45 Does water flow out of the forebay in a non -erosive manner? Yes 46 Width of the vegetated shelf (feet) 12 ft 47 Slope of vegetated shelf (H:V) 6:1 48 Does the orifice drawdown from below the top surface of the Yes permanent pool? 49 Does the pond minimize impacts to the receiving channel from the 1- Yes yr, 24-hr storm? 50 Are fountains proposed? (If Y, please provide documentation that No MDC(?) is met) 51 Is a trash rack or other device provided to protect the outlet system? Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes 53 Species of turf that will be used on the dam and embankment Bermudagrass 54 Has a Rlantm flan been provided for the vegetated shelf Yes ADDITIONAL INFORMATION Please use this s ace to rovde an additional information about p p Y 55 the wet pond(s): Berm is used to direct inflow to shallow end of forebay, away from outlet. Wet Pond 1 12:08 PM 7/27/2023