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HomeMy WebLinkAboutSW5210202_Supplement-EZ Form_20210611DRAINAGE AREAS ............................................................................................................................................................................................................................................................................ 1 Is this a high density project? Yes 2 If so, number of drainage areas/SCMs 1 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 Is all/part of this project subject to previous rule 5 versions? No Mai a I.. LD.F.D DRAINAGE AREA INFORMATION��������������������� Ent°ire S°ite 1��������� 4 T e of SCM wetpond 5 Total drainage area (sq ft 1226463 64812 6 Onsite drainage area (sq ft 1226463 64812 7 Offsite drainage area (sq ft) 0 0 8 Total BUA in roject (sq ft 220948 sf 25934 sf New BUA on subdivided lots (subject to 9 permitting) (sq ft) .... New BUA not on subdivided lots (subject to 10 permitting) (sq 11 Offsite BUA (sq ft) 12 Breakdown of new BUA not on subdivided lots: Parking„ (sq ft) 6237 sf 6237 sf Sidewalk (sq ft).... 623 sf 623 sf Roof (sq ft) 7694 sf 7694 sf Roadway (sq ft) 9281 sf 9281 sf 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 s ft Existing BUA that will remain (not subject to 15 permitting) (sq ft) 197113 sf 2099 sf 16 Existing BUA that is already permitted (sq ft) 17 Existing BUA that will be removed (sq ft) 1434 sf 1434 sf 18 I Percent BUA 18% 40% 19 Design storm (inches) 1.0 in 20 Design volume of SCM (cu ft) 2098 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) FORMS LOADED Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here, yyY�"� �^�'�yywrwrrrrarrrir,� •��r a SEAL � 34374 '4 jktoO Z' All NR0,1 .000h A A In1,it tit'it4 S nature of ftestlgmer z Date WET POND 1 Drainage area number 1 2 Mmimum required treatment volumecu ft) ...... ...... ...... ...... ...... .... 2231 cf GENERAL MDC FROM 02H�.1050������������� 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? Drawdown Orifice 10 If applicable will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comp!coTp!y 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 NC licensed �rofessronal Was the SCM desi Heil bar an � 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 244.00 removal) (fmsl) 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 245.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 250.50 23 Elevation of the permanent pool (fmsl) 251.00 24 Elevation of the top of the vegetated shelf (fmsl) 251.50 25 Elevation of the temporary pool (fmsl) 251.40 26 Surface area of the main permanent pool (square feet) 4109 27 Volume of the main permanent pool (cubic feet) 13374 cf 28 Average depth of the main pool (feet) 3.50 ft 29 Average depth equation used Equation 3 30 If using equation 3, main pool perimeter (feet) 290.0 ft 31 If using equation 3, width of submerged veg. shelf (feet) 3.0 ft 32 Volume of the forebay (cubic feet) 2500 cf 33 Is this 15-20% of the volume in the main pool? Yes 34 Clean -out depth for forebay (inches) 60 in 35 Design volume of SCM (cu ft) 12531 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice, orifice diameter (inches) 1 in 38 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 2.9 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) 72 in 44 Depth of forebay at exit (inches) 72 in 45 Does water flow out of the forebay in a non -erosive manner? Yes 46 Width of the vegetated shelf (feet) 6 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(9) 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 tall fescue 54Hasa�lantinc�lan�been�rovidedforthe�ve�etated�shelf?�������� Yes ADDITIONAL INFORMATION 55 Please use this s aCe to rovde an additional ................................................t p p Y the wet pond(s): Wet Pond 1 9:45 AM 6/11/2021