HomeMy WebLinkAboutSW3181002_Supplement-EZ Form_20230918 SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 1Project Name Cottages West/Cottages at Indian Trail
2 Project Area(ac) 12.67
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) 30
8 Will the vegetated setback remain vegetated? N/A
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
12 Bioretention Cell
13 Wet Pond
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter 2
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 1Name and Title: Nicholas T.Vesely,PE(Engineer)
28 Organization: V3 Southeast
29 Street address: 2923 S.Tryon St.,Suite 320
30 City,State,Zip: Charlotte,NC,28203
31 Phone number(s): 704.940.2883
32 Email: NVesely@V3Co.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 2
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 2
4 Type of SCM Sand Filter Sand Filter
5 Total drainage area(sq ft) 652,964 292,723 360,241
6 Onsite drainage area(sq ft) 436,459 156,816 279,643
7 Offsite drainage area(sq ft) 216,635 136037 80598
8 Total BUA in project(sq ft) 213008 sf 60548 sf 152460 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft) 153767 sf 38333 sf 115434 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 59241 sf 22215 sf 37026 sf
11 Offsite BUA(sq ft) 217059 sf 136037 sf 81022 sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft)
-Sidewalk(sq ft) 16534 sf 6179 sf 10355 sf
-Roof(sq ft)
-Roadway(sq ft) 43549 sf 16556 sf 26993 sf
-Future(sq ft)
-Other,please specify in the comment box
below(sq ft) 380 sf 380 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) N/A
16 Existing BUA that is already permitted(sq ft)
17 Existing BUA that will be removed(sq ft)
18 Percent BUA 66% 67% 65%
19 Design storm(inches) 1.0 in 1.0 in
20 Design volume of SCM(cu ft) 14065 cf 22131 cf
21 Calculation method for design volume SCS TR-20 SCS TR-20
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
The drainage areas do not vary greatly from the previous design,however.
The 380 sf above indicates the amount of sidewalk that is bypassed around
the site.
SAND FILTER
1 Drainage area number 1 2
2 Minimum required treatment volume(cu ft) 11975 sf 14460 sf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yco Yeo
4 Is the SCM located away from contaminated soils? Yes Yes
5 What are the side slopes of the SCM(H:V)? 3:1 3:1
6 Does the SCM have retaining walls,gabion walls or other No Yes
engineered side slopes?
7 Are the inlets,outlets,and receiving stream protected from erosion Yes Yes
(10-year storm)?
8 Is there an overflow or bypass for inflow volume in excess of the Yes Yes
design volume?
9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice Drawdown Orifice
10 If applicable,will the SCM be cleaned out after construction? Yes Yes
11 Does the maintenance access comply with General MDC(8)? Yes Yes
12 Does the drainage easement comply with General MDC(9)? Yes Yes
If the SCM is on a single family lot,does(will?)the plat comply with
13 N/A N/A
General MDC(10)?
14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes
16 Does the SCM follow the device specific MDC? Yes Yes
17 Was the SCM designed by an NC licensed professional? Yes Yes
SAND FILTER MDC FROM 02H.1056
18 SHWT elevation(fmsl) <668 <650
19 Type of sand filter(open or closed) _ Open Open _
20 If closed,will the filter will be pre-cast or pour-in-place?
21 If closed,top of grate elevation(fmsl)
22 Is this sand filter designed to attenuate peak flows? No No
Sediment Chamber
23 Volume that can be retained in the sediment chamber(cubic feet) 5733 cf 12586 cf
24 Will there be a permanent pool in the sediment chamber? No No
25 Bottom of the sediment chamber(fmsl) 668.00 657.00
26 Area of the sediment chamber(square feet) 1911 sf 5034 sf
27 Physical depth of the sediment chamber(inches) 36 in 30 in
28 Ponding depth in the sediment chamber,above any permanent 36 in 30 in
pool(inches) _
29 Elevation of top of weir between chambers(fmsl) 671 659.5
Sand Chamber
30 Volume that can be retained in the sand chamber(cubic feet) 8332 cf 9545 cf
31 Bottom of the sand chamber(fmsl) 667.00 657.00
32 Area of the sand chamber(square feet) 2777 sf 3278 sf
33 Physical depth of the sand chamber(inches) 36 in 30 in
34 Ponding depth in the sand chamber,above the sand surface 25 in 30 in
(inches)
35 Elevation of the bypass device(fmsl) 671 659.5
36 Type of bypass device Outlet Control Outlet Control
Structure Structure
Rip-rap forebay to Rip-rap forebay to
37 Mechanism for distributing flow over the sand surface act as level act as level
spreader spreader
38 Sand specification for sand chamber ASTM C-33 ASTM C-33
39 Depth above underdrain pipe(inches) 12 in 12 in
40 Will the media be maintained to drain at least two inches per hour at Yes Yes
the sand surface?
41 Is at least one clean-out pipe provided at the low point of each Yes Yes
underdrain line?
42 Will clean-out pipes be capped? Yes Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about
43 the sand filter(s):