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HomeMy WebLinkAboutSW3230802_Supplement-EZ Form_20230810 SUPPLEMENT-EZ COVER PAGE FORMS LOADED ,PROJECT INFORMATION 1 Project Name Green Acres Subdivision 2 Project Area(ac) 14.72 3 Coastal Wetland Area(ac) 0 4 Surface Water Area(ac) 0 5 Is this project High or Low Density? High 6 Does this project use an off-site SCM? No COMPLIANCE WITH 02H.1003(4) 7 Width of vegetated setbacks provided(feet) 25 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMs: 11 I Infiltration System 12 Bioretention Cell 13 Wet Pond 1 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 17 Rainwater Harvesting(RWH) 18 Green Roof 19 Level Spreader-Filter Strip(LS-FS) 20 Disconnected Impervious Surface(DIS) 21 Treatment Swale 22 Dry Pond 23 StormFilter 24 Silva Cell 25 Bayfilter 26 Filterra FORMS LOADED DESIGNER CERTIFICATION 27 Name and Title: Barry Fay,Project Engineer 28 Organization: American Engineering Associates 29 Street address: 8008 Corporate Center Dr.Suite 110 30 City,State,Zip: Charlotte,NC 28226 31 Phone number(s): 704-375-2438 32 Email: bfay@american-ea.com 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. Designer Signature of Designer Seal Date DRAINAGE 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 FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 4 Type of SCM Wet Pond 5 Total drainage area(sq ft) 641,247 532,346 6 Onsite drainage area(sq ft) 641,247 532,346 7 Offsite drainage area(sq ft) 0 0 8 Total BUA in project(sq ft) 249469 sf 228560 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) 135428 sf 135428 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 114041 sf 93132 sf 11 Offsite BUA(sq ft) n/a n/a 12 Breakdown of new BUA not on subdivided lots: _ -Parking(sq ft) -Sidewalk(sq ft) 21432 sf 21432 sf -Roof(sq ft) -Roadway(sq ft) 71700 sf 71700 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) 20909 sf 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) 18 Percent BUA 39% _ 43% 19 Design storm(inches) 1.0 in 20 Design volume of SCM(cu ft) 19360 cf 21 Calculation method for design volume Simple Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): Item#12 other BUA includes existing Green Acres Circle improvements. WET POND 1 Drainage area number 1 I 2 Minimum required treatment volume(Cu ft) 19360 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 Does the SCM have retaining walls,gabion walls or other 6 No engineered side slopes? Are the inlets,outlets,and receiving stream protected from erosion 7(10-year storm)? Yes 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 comply with General MDC(8)? Yes 12 Does the drainage easement comply with General MDC(9)? Yes If the SCM is on a single family lot,does(will?)the plat comply with 13 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 designed by an NC licensed professional? 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 647.00 removal)(fmsl) 21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 648.00 22 Elevation of the bottom of the vegetated shelf(fmsl) 653.50 23 Elevation of the permanent pool(fmsl) 654.00 24 Elevation of the top of the vegetated shelf(fmsl) 654.50 25 Elevation of the temporary pool(fmsl) 655.68 26 Surface area of the main permanent pool(square feet) 7077 27 Volume of the main permanent pool(cubic feet) 29443 cf 28 Average depth of the main pool(feet) 4.16 ft 29 Average depth equation used Equation 2 30 If using equation 3,main pool perimeter(feet) 31 If using equation 3,width of submerged veg.shelf(feet) 32 Volume of the forebay(cubic feet) 6127 cf 33 Is this 15-20%of the volume in the main pool? Yes 34 Clean-out depth for forebay(inches) 24 in 35 Design volume of SCM(cu ft) 35570 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice,orifice diameter(inches) - 38 If weir,weir height(inches) 39 If weir,weir length(inches) 40 Drawdown time for the temporary pool(days) 2.6 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? Yes 43 Depth of forebay at entrance(inches) 60 in 44 Depth of forebay at exit(inches) 36 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) 4:1 48 Does the orifice drawdown from below the top surface of the Yes permanent pool? Does the pond minimize impacts to the receiving channel from the 1- 4 Yes 9 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 Bermuda 54 Has a planting plan been provided for the vegetated shelf? Yes ADDITIONAL INFORMATION Please use this space to provide any additional information about 55 the wet pond(s): 2