SW3220805_Supplement-EZ Form_20220921

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
iPROJECT INFORMATION
1 Project Name
2 Project Area (ac)
3 Coastal Wetland Area (ac)
4 Surface Water Area (ac)
5 Is this project High or Low Density?
6 Does this project use an off -site SCM?
of Granite C
8.72
0
0
High
No
Phase III
COMPLIANCE WITH 02H .1003(4)
7
Width of vegetated setbacks provided (feet)
20' Landscape Buffer
8
Will the vegetated setback remain vegetated?
Yes
9
Ilf BUA is proposed in the setback, does it meet NCAC 02H.1003(4)(c-d)?
N/A
10
I Is streambank stabilization proposed on this project?
No
NUMBER AND T
11
Infiltration System
0
12
Bioretention Cell
0
13
Wet Pond
1
14
Stormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
1
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
Storm Filter
0
24
Silva Cell
Bayfilter
Filterra
0
25
0
26
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
28
Organization:
29
Street address:
30
City, State, Zip:
31
1 Phone number(s):
32
Email:
Allen Mcdowell
Bohler Engineering, NC
1927 S. Tryon Street, Suite 310
Charlotte, NC 28203
[phone]
[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.
\ 0� CAROZ/
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046878
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'00` 03/28/22
Signature of Designer
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?
yes
4
If so, number of low density drainage areas
2
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
1
2
LD 1
LD 2
4
Type of SCM
Wet Pond
Sand Filter
Bypass PO13
Bypass PO14
5
Total drainage area (sq ft)
411754
222383
130996
42690
15685
6
Onsite drainage area (sq ft)
375720
216097
110038
33900
15685
7
Offsite drainage area (sq ft)
36034
6286
20958
8790
0
8
Total BUA in project (sq ft)
180495 sf
91430 sf
58350 sf
30715 sf
sf
9
New BUA on subdivided lots (subject to
permitting) (sq ft)
73290
34420 sf
28470 sf
10400 sf
sf
10
New BUA not on subdivided lots (subject to
permitting) (so
66470
34860 sf
29880 sf
1730 sf
11
Offsite BUA (sq ft)
40735 sf
22150 sf
sf
18585 sf
sf
12
Breakdown of new BUA not on subdivided lots:
Parking (sq ft)
4290 sf
2340 sf
1950 sf
sf
sf
Sidewalk (sq ft)
7460 sf
3050 sf
2680 sf
1730 sf
sf
Roof (sq ft)
48880 sf
28470 sf
20410 sf
sf
sf
Roadway (sq ft)
54720 sf
29470 sf
25250 sf
sf
sf
Future (sq ft)
sf
sf
sf
sf
sf
Other, please specify in the comment box
below (sq ft)
sf
sf
sf
sf
sf
13
New infiltrating permeable pavement on
subdivided lots (sq ft)
0
sf
sf
sf
sf
14
New infiltrating permeable pavement not on
subdivided lots (sq ft)
0
sf
sf
sf
sf
15
Existing BUA that will remain no subject to
permitting) (sq ft)
40735 sf
22150 sf
sf
18585 sf
sf
16
Existing BUA that is already permitted (sq ft)
0
sf
sf
sf
sf
17
Existing BUA that will be removed (sq ft)
0
sf
sf
sf
sf
18
Percent BUA
42.82854952
41%
45%
72%
0%
19
Design storm (inches)
1 in
1 in
1 in
n/a
n/a
20
Design volume of SCM (cu ft)
23904
16001
7903
n/a
n/a
21
Calculation method for design volume
scs
scs
scs
n/a
n/a
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s): J

WET POND
1 11Drainage area number 1
21 Minimum reauired treatment volume (cu ft) 13448 cf
ERAL 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)?
2:1
6
Does the SCM have retaining walls, gabion walls or other
engineered side slopes?
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10-year storm)?
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
9
What is the method for dewaterin the SCM for maintenance?
Pumpreferred
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
General MDC (10)?
Yes
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
161
Does the SCM follow the device specific MDC?
Yes
17
Was the SCM designed by an NC licensedprofessional?
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
removal) (fmsl)
754.00
21
Elevation of the main pool bottom (top of sediment removal) (fmsl)
749.00
22
Elevation of the bottom of the vegetated shelf (fmsl)
754.00
23
Elevation of the permanent pool (fmsl)
754.00
24
Elevation of the top of the vegetated shelf (fmsl)
755.00
25
Elevation of the temporary pool (fmsl)
754.21
26
Surface area of the main permanent pool (square feet)
10252
27
Volume of the main permanent pool (cubic feet)
43890 cf
28
Average depth of the main pool (feet)
4.28 ft
29
Average depth equation used
Equation 2
301
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)
1200 cf
33
Is this 15-20% of the volume in the main pool?
Yes
34
Clean -out depth for forebay (inches)
6 in
35
Design volume of SCM (cu ft)
68712 cf
36
Is the outlet an orifice or a weir?
Orifice
371
If orifice, orifice diameter (inches)
2 in
38
If weir, weir height (inches)
39
If weir, weir length (inches)
40
Drawdown time for the temporary pool (days)
2.95
41
Are the inlet(s) and outlet located in a manner that avoids short-
circuiting?
Yes
42
Are berms or baffles provided to improve the flow path?
No
431
Depth of forebay at entrance (inches)
60 in
44
Depth of forebay at exit (inches)
60 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
permanent pool?
Yes
49
Does the pond minimize impacts to the receiving channel from the 1-
yr, 24-hr storm?
Yes
50
Are fountains proposed? (If Y, please provide documentation that
MDC(9) is met.)
No
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
541
Hasa plantinq plan been provided for the vegetated shelf?
Yes
ADDITIONAL
INFORMATION 11
55
Please use this space to provide any additional information about
the wet pond(s):
Wet Pond 3 3:41 PM 5/10/2022

SAND FILTER
1 Drainage area number 2
2 Minimum reauired treatment volume (cu ft) 7897 sf
ERAL MDC FROM 02H .1050
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Y-es
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 side slopes?
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10-year storm)?
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
9
What is the method for dewaterin the SCM for maintenance?
Pumpreferred
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
General MDC (10)?
Yes
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
161
Does the SCM follow the device specific MDC?
Yes
17
Was the SCM designed by an NC licensedprofessional?
Yes
SAND FILTER
MDC FROM 02H .1056
18
SHWT elevation (fmsl)
N/A
19
Type of sand filter (open or closed)
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?
Yes
Sediment Chamber
23
Volume that can be retained in the sediment chamber (cubic feet)
1579 cf
24
Will there be a permanent pool in the sediment chamber?
No
25
Bottom of the sediment chamber (fmsl)
752.00
26
Area of the sediment chamber (square feet)
24 in
27
Physical depth of the sediment chamber (inches)
Ponding depth in the sediment chamber, above any permanent
ool (inches)
Elevation of top of weir between chambers (fmsl)
28
54 in
29
754
Sand Chamber
30
Volume that can be retained in the sand chamber (cubic feet)
7903 cf
31
Bottom of the sand chamber (fmsl)
752.00
32
Area of the sand chamber (square feet)
800 sf
33
Physical depth of the sand chamber (inches)
72 in
34
Ponding depth in the sand chamber, above the sand surface
inches
in
351
Elevation of the bypass device (fmsl)
754
36
Type of bypass device
Weir
37
Mechanism for distributing flow over the sand surface
sheet flow
38
Sand specification for sand chamber
ASTM C-33
39
Depth above underdrain pipe (inches)
12 in
40
Will the media be maintained to drain at least two inches per hour at
the sand surface?
Yes
41
Is at least one clean -out pipe provided at the low point of each
underdrain line?
Yes
42
Will clean -out pipes be capped?
Yes
ADDITIONAL
INFORMATION
43
Please use this space to provide any additional information about
the sand filter(s):
Sand Filter 4 3:41 PM 5/10/2022