SW6230805_Supplement-EZ Form_20240711

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION--- '-�--- -"'"--`-- -"'--"`"—"'—'—""'_______s..____•._._.--- a__
1 I Project Name Turnberry South Phase 1
2 Project Area(ac) 18.92
3 Coastal Wetland Area(ac) . -
4 Surface Water Area(ac) -
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) 30
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)? N/A
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11 Infiltration System 0
12 Bioretention Cell 1
13 Wet Pond 1
14 Stormwater Wetland 0
15 Permeable Pavement 0
16 Sand Filter 0
17 Rainwater Harvesting(RWH) 0
18 Green Roof 0
19 Level Spreader-Filter Strip(LS-FS) 0
20 Disconnected Impervious Surface(DIS) 0
21 Treatment Swale 0
22 Dry Pond 0
23 StormFilter 0
24 Silva Cell 0
25 i Bayfilter 0
26 I Filterra 0
FORMS LOADED
DESIGNER CERTIFICATION
27 'Name and Title: Carlo Pardo, PE
28 Organization: Bowman North Carolina,Ltd.
29 Street address: 4006 Barrett Drive,Suite 104
30 City,State,Zip: Raleigh,NC 27609
31 Phone number(s): 919-553-6570
32 Email: [e-mail]
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
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DRAINAGE AREAS
1 Is this a high density project? Yes ,
2 ! If so,number of drainage areas/SCMs 2
3 Does s this project have low density areas? No 4
4 i If so,number of low density drainage areas 0 J
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site 1 2
4 Type of SCM - Wet Pond BioRetention
5 Total drainage area(sq ft) 824106 sf 403800 616411
6 Onsite drainage area(sq ft) 824106 sf 403800 328663
7 Offsite drainage area(sq ft) 287748
8 Total BUA in project(sq ft) 328773 sf • 208172 sf 266449 sf
New BUA on subdivided lots(subject to permitting)
9 (sq ft) 216000 sf 120000 sf 96000 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 112773 sf 88172 sf 24601 sf
11 Offsite BUA(sq ft) 145848 sf
12 ;Breakdown of new BUA not on subdivided lots:
-Parking(sq ft)
_ -Sidewalk(sq ft) 22692 sf 17159 sf 5533 sf
-Roof(sq ft)
-Roadway(sq ft) 90081 sf 71013 sf 19068 sf
-Future(sq ft)
i -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(q ft)
17 Existing BUA that will be removed(sq ft)
18 Percent BUA 39.89% 51.6% 43.2%
19 Design storm(inches) 1.0 in 1.0 in
20 Design volume of SCM(cu ft) _ _ 19332 cf 26625 cf
21 Calculation method for design volume Simple Method Simple Method
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Drainage Area 2's offsite area is on Parcel 494550301299.The offsite BUA
will include 88,000 sf on 22 lots,and 57,848 sf of roadways and sidewalks.

BIORETENTION CELL
1 Drainage area number 2
2 Minimum required treatment volume(cu ft) 22552 cf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? i Yes
4 Is the SCM located away from contaminated soils? 1Yes _
5 What are the side slopes of the SCM(H:V)? 3:1
Does the SCM have retaining walls,gabion walls or other engineered
6 side slopes? No
Are the inlets,outlets,and receiving stream protected from erosion
7 (10-year storm)? Yes
Is there an overflow or bypass for inflow volume in excess of the
8 design volume? Yes
g 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 designed by an NC licensed professional? Yes
BIORETENTION CELL MDC FROM 02H.1052
18 SHWT elevation(fmsl) 205.00
' 19 Bottom of the bioretention cell(fmsl) 220.00
20 Ponding depth of the design storm(inches) 7 in
21 Surface area of the bioretention cell(square feet) 43600 sf
22 Design volume of SCM(Cu ft) 26625 cf
23 Is the bioretention cell used for peak attenuation? Yes
24 Depth of peak attenuation over planting surface(in) 29.16 in
25 Height of peak attenuation outlet above the planting surface(in) 29.16 in
26 Infiltration rate of the in situ soil(inch/hour) 2 in/hr
27 Diameter of the underdrain pipes(if applicable) 4 in
28 Does the design include Internal Water Storage(IWS)? Yes
29 if so,elevation of the top of the IWS(fmsl) 218.5
30 Elevation of the planting surface(fmsl) 220.00
31 What type of vegetation will be planted? (grass,trees/shrubs,
other)? I Grass
32 Media depth(inches) I 30 in
_33 Percentage of medium to coarse washed sand by volume ; 75-85%
_34 Percentage of fines(silt and clay)by volume 8-10% _
35 Percentage of organic matter by volume 5-10%
36 Type of organic material Pine Bark Fines
37 ;Phosphorus Index(P-Index)of media(unitless) 30 —
38 Will compaction be avoided during construction? Yes
39 Will cell be maintained to a one inch/hour standard? Yes
40 Depth of mulch,if applicable(inches) ,
41 Type of mulch,if applicable
42 How many clean out pipes are being installed? 47
43 Type of pretreatment that will be used: Forebay
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
bioretention cell(s):LA4 :
Bioretention 1 1:04 PM 6/21/2024

WET POND
1 Drainage area number ; 1
2 Minimum required treatment volume(cu ft) ; 17295 cf I
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 engineered Yes
side slopes?
7Are the inlets,outlets,and receiving stream protected from erosion Yes
(10-year 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(preferredL
- 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 WA
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 220.00
removal)(fmsl)
21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 221.00
22 Elevation of the bottom of the vegetated shelf(fmsl) 226.50
23 Elevation of the permanent pool(fmsl) 227.00
24 Elevation of the top of the vegetated shelf(fmsl) 227.50
25 Elevation of the temporary pool(fmsl) 228.30
_ 26 Surface area of the main permanent pool(square feet) 9630 _
27 Volume of the main permanent pool(cubic feet) 41228 cf
28 Average depth of the main pool(feet) 4.67 ft
29 Average depth equation used Equation 3
30 If using equation 3,main pool perimeter(feet) 446.0 ft
31 If using equation 3,width of submerged veg.shelf(feet) 3.0 ft
32 Volume of the forebay(cubic feet) 7830 cf
33 Is this 15-20%of the volume in the main pool? Yes
34 Clean-out depth for forebay(inches) 12 in
35 Design volume of SCM(cu ft) 19332 cf
36 Is the outlet an orifice or a weir? Orifice
37 If orifice,orifice diameter(inches) 2.00 in
38 If weir,weir height(inches) r
39 If weir,weir length(inches)
40 Drawdown time for the temporary pool(days) 2.55
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) 30 in
44 Depth of forebay at exit(inches) 24 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 Hybrid Bermuda
54,Has a planting plan been provided for the vegetated shelf? Yes
ADDITIONAL INFORMATION
55'Please use this space to provide any additional information about the
wet pond(s):
Wet Pond MDC 6 requires that the main pool be equipped with a vegetative shelf
around it's perimeter.No vegetated shelf is provided along the perimeter of the
retaining wall.However,the retaining wall includes a fence that will deter any humans
from getting into the pond.Therefore.the fence on the retaining wall meets the
requirements for MDC 6.
Wet Pond 1 1:04 PM 6/21/2024