SW3191101_Supplement-EZ Form_20200414

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name
2 1Projecl Area (ac)
3 `Coastal Wetland Area (ac)
4 Surface Water Area (ac)
5 41s this project Hlgh or Low Densily?
6 Does this project use an off -site SCM7
WITH 02H A-1011i
7 Width of vegetated setbacks provided (feet)
8 Will the vegetated setback remain vegetated?
9 _ is BLIA dharthat as listed in .1003(4)(c-d) out of the setback?
10 Is streambank stabilization proposed on this project?
t AND TYPE OF SCMa:
11
Infiltration System___
12
19ioretant1on Call
13
Wet Pond _
14
Stormwaler Welland _
15
Permeable Pavement
16
Sand Filler _
1.7
Harvesling (RWH) _
18
�Rainwalef
Green Roof
19
Level Spreader-Fi ter Strip (LS•FS)
20
Disconnected imp ervlous Surface (DIS) ,
21
Treatment Swale —
4 _
dry Pond _
23
StormFliter
24
Silva Call
25
Beylilter
26
Filterra
FORMS LOADED
Cambridge Village Multifamily
10.6
0
High
No
0
0
0
iDr=S14NER CERTIFICATION
27 Name and Title: Stave Farmanino, Project Manager _
28 Organizallory _ ^�8ohter Engineering
29 Street address 1927_South tlyan_st Suite 310
30 City, State, Zip; — Charlotte, NC 28204
31 IPhone number(s). _ (9e0} 272-3400
32 :Email; [e-mail]
flien. ns
1 certify, under penalty of law that this Supplement-EZ form and all supporting Information were prepared under my dlrectlon or
supervision; that the informstlon provided In the form Is. to the beet of my knowledge and belief, true, soourate, and complete; and
that the engineering plans, speolflcatlons, operatlon and maintenance agreements and other supporting Information are oonaletent
with the Information provided here,
,`��`a'`�, 11t1C1,11� it�'I
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SEAL
5 0473% x
Date

DRAINAGE AREAS
1
Is this a high density project?
Yes
2
If so, number of drainage areas/SCMs
3
3
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
1
2
3
4
Type of SCM
N/A
Wet Pond
Wet Pond
N/A
5
Total BUA in project (sq ft
306887 sf
94530 sf
194933 sf
17424 sf
6permitting)
New BUA on subdivided lots (subject to
s ft
N/A
N/A
N/A
N/A
7permitting)
New BUA outside of subdivided lots (subject to
s
Offsite - total area (sq ft
Offsite BUA (sq ft
289463 sf
94530 sf
194933 sf
sf
8
75376 sf
sf
39722 sf
35654 sf
9
17424 sf
sf
sf
17424 sf
10
Breakdown of new BUA outside subdivided lots:
N/A
Parking (sq ft
158317 sf
51905 sf
106412 sf
Sidewalk (sq ft
25381 sf
8045 sf
17336 sf
Roof (sq ft
104465 sf
34580 sf
69885 sf
Roadway s ft
sf
sf
sf
sf
Future (sq ft
sf
sf
sf
sf
Other, please specify in the comment box
below (sq ft
1300 sf
sf
1300 sf
sf
11
New infiltrating permeable pavement on
subdivided lots (sq ft
sf
sf
sf
sf
12
New infiltrating permeable pavement outside of
subdivided lots (sq ft
sf
sf
sf
sf
13permitting)
Exisitng BUA that will remain (not subject to
s ft
17424 sf
sf
17424 sf
14
Existing BUA that is already permitted (sq ft
17424 sf
sf
17424 sf
15
Existing BUA that will be removed (sq ft
17276 sf
sf
17276 sf
16
Percent BUA
62%
69%
61 %
30%
17
Design storm inches
1 in
1 in
N/A
18
Design volume of SCM cu ft
Calculation method for design volume
7726 cf
15950 cf
N/A
19
Simple Method
Simple Method
N/A
DDITIONAL INFORMATION
Please use this space to provide any additional information about the
20 drainage area(s):
1300 sf "other" BUA is ammenity area at clubhouse
Drainage Area 2 offsite total area is portion of BMP on adjacent lot.

WET POND
1
Drainage area number Prop DA-1
Prop DA-2
21 Design volume of SCM (cu ft) 7726 cf 15950 cf
GENERAL MDC FROM 02H .1050
3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes
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
engineered side slopes?
No
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10-year storm)?
Yes
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
Yes
9
What is the method for dewatering the SCM for maintenance?
Pump (preferred)
Pump (preferred)
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
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC (10)?
No
No
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 speck MDC?
Yes
Yes
17
Was the SCM designed by an NC licensed professional?
MDC FROM 02H .1053
Yes
SA/DA
Yes
SA/DA
WET POND
18
Method used
19
Has a stage/storage table been provided in the calculations?
Yes
Yes
20
Elevation of the excavated main pool depth (bottom of sediment
removal) (fmsl)
781.00
769.00
21
Elevation of the main pool bottom -(top of sediment removal) (fmsl)
782.00
770.00
22
Elevation of the bottom of the vegetated shelf (fmsl)
787.00
776.00
23
Elevation of the permanent pool (fmsl)
787.50
777.00
24
Elevation of the top of the vegetated shelf (fmsl)
788.00
777.00
25
Elevation of the temporary pool (fmsl)
788.50
778.30
26
Surface area of the main permanent pool (square feet)
5852:1
8292:1
27
Volume of the main permanent pool (cubic feet)
20834 cf
31220 cf
28
Average depth of the main pool (feet)
4.15 ft
5.30 ft
29
Average depth equation used
Equation 3
Equation 3
30
If using equation 3, main pool perimeter (feet)
306.0 ft
407.0 ft
31
If using equation 3, width of submerged veg. shelf (feet)
3.0 ft
6.0 ft
32
Volume of the forebay (cubic feet)
3575 cf
5808 Gf
33
Is this 15-20 % of the volume in the main pool?
Yes
Yes
34
Clean -out depth for forebay (inches)
42 in
48 in
35
Design volume of SCM (cu ft)
7726 cf
15950 cf
36
Is the outlet an orifice or a weir?
Orifice
Orifice
37
If orifice, orifice diameter (inches)
1.5 in
2.0 in
38
If weir, weir height (inches)
39
If weir, weir length (inches)
40
Drawdown time for the temporary pool (days)
2.71
2.76
41
Are the inlet(s) and outlet located in a manner that avoids short-
circuiting?
No
Yes
42
Are berms or baffles provided to improve the flow path?
Yes
No
43
Depth of forebay at entrance (inches)
60 in
66 in
44
Depth of forebay at exit (inches)
48 in
54 in
45
Does water flow out of the forebay in a non -erosive manner?
Yes
Yes
46
Width of the vegetated shelf (feet)
6 ft
6 ft
47
Slope of vegetated shelf (H:V)
6:1
6:1
48
Does the orifice drawdown from below the top surface of the
permanent pool?
Yes
Yes
49
Does the pond minimize impacts to the receiving channel from the 1
yr, 24-hr storm?
Yes
Yes
50
Are fountains proposed? (If Y, please provide documentation that
MDC(9) is met.)
No
No
51
Is a trash rack or other device provided to protect the outlet system?
Yes
Yes
52
Are the dam and embankment planted in non -clumping turf grass?
Yes
Yes
53
Species of turf that will be used on the dam and embankment
Bermuda
Bermuda
54
Has a planting plan been provided or the vegetated she
Yes Yes
ADDITIONAL
INFORMATION
55
Please use this space to provide any additional information about
the wet pond(s):
Wet Pond 3 11:14 AM 4/14/2020