SW4191201_17-116 - SuppEZ-2018-Version-2.1.1 2_1/2/2020

SUPPLEMENT-EZ COVER PAGE
f•ORMSLOADE❑
PROJECT INFORMATION
1
jProject Name
Lewisville Middle School
i 66.21
2
lProiect Area ac
3
Coastal Wetland Area ac
0
1.28
4
Surface Water AreaLac)
5
Is this project H' h or Low Density?
Hi h
6
Does this project use an off -site SCM?
No
COMPLIANCE WIT..'02H .1 _ S 4}.
f ve etated setbacks rovided feet
30
T7d
ve etated setback remain ve etated?
Yes
otherthat as listed in ,1003 4 c-d out of the setback?
Yes
mbank stabilization proposed on this project?
Yes
NUMBER
AND TYPE OF SCMs:
11
Infiltration S stem
0
12
Bioretention Cell
0
13
Wet Pond
1
14
Stormwater Wetland
1
15
Permeable Pavement
0
16
Sand Filter
_
0
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level S reader -Filter Stri LS-FS
0
20
Disconnected Impervious Surface DIS
0
21
Treatment Swale
0
22
IDry Pond
_
0
23
StormFilter
0
24
Silva Cell
0
25
Bayfilter
0
26
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Kenneth Lorin - Principal
28
Organization:
CLH Design PA
29
Street address:
400 Regency Forest Drive. Suite 120
30
City, State, Zip:
Cary, NC
31
Phone numbers :
919-319-6716
32
Email:
27518
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.
'fes IL
N r.
SEAL
23953 -
P
nature of Designer
Date
/z- 3 49

DRAINAGE AREAS
hi h densit roject?
Yes
number of draina a areas/SCMs
Fa
2
part of this project subject to previous rule
ns?
No
FORMS LOADED
p1AINAGE
AREA INFORMATION
M re Sike
1
4
Type of SCM
NIA
WET POND
WETLAND
5
Total BUA in pLoject (sq It)
388943 sf
349943 sf
32979 sf
6
New BUA on subdivided lots (subject to
ermittin s ft
NIA
N/A
NIA
7
New BUA outside of subdivided lots (subject to
ermittin sf
382❑98 sf
349119 sf
32979 sf
8
Offsite • total area (sq ft
0
19602 sf
0
9
Offsite BUA Lsq ft
0
0
0
10
Breakdown of new BUA outside subdivided lots:
Parking (sq ft
105490 sf
105490 of
0
Sidewalk (sq ft
25206 sl
23189 sf
2017 sf
Roof sa ft
62264 sf
62264 sf
0
Roadwa s it)
121582 sf
93234 sf
28348 sf
Future (sq It)
11326 sf
8712 sf
2614 sf
Other, please specify in the comment box
below (sq ft
56230 sf
58230.sf
0
11
New infiltrating permeable pavement on
subdivided lots (sq ft
0
❑
0
12
New infiltrating permeable pavement outside of
subdivided lots (sq ft
0
0
0
13permitting)
Exisitng BUA that will remain (not subject to
s ft
8021 sf
824 sf
0
14
Existing BUA tltal is already permitted Jsq ft
0
0
0
15
Existing BUA that will be removed s ft
24871 sf
23202 sf
284 sf
16
Percent BUA
14%
43%
37'/e
17
Design storm inches
NIA
1 In
1 In
18
Design valume of SCM cu ft
N(A
29521 cf
2822 cf
19
Calculation method for design volume
N/A
HRT
(Rain
Do Ih}(Rv}jDA}
APOITIONAL INFORMATION
20
Please use this space to provide any additional information about the
drainage area(s):
"Other" BUA includes gravel fire lane and `rook dust" track

WET POND
1 Drainage area number 1
2 Design volume of SCM (cu fto 29521 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
6
Does the SCM have retaining walls, gabion walls or other engineered
side slopes?
Are the inlets, outlets, and receiving stream protected from erosion
(10-year storm)?
Is there an overflow or bypass for inflow volume in excess of the
design volume?
What is the method for dewatering the SCM for maintenance?
No
7
Yes
Yes
8
9
Drawdown Orifice
Yes
10
If applicable, will the SCM be cleaned out after construction?
11
Does the maintenance access comply with General MDC (8)?
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
No
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC (10)?
Is there an O&M Agreement that complies with General MDC (11)?
Is there an O&M Plan that complies with General MDC (12)?
141
15
Yes
16
Does the SCM follow the device specific MDC?
Yes
17 Was the SCM designed by an NC licensed professional?
WET PONE? MDC FROM 02H .1053
18 Method used
19 Has a stage/storage table been provided in the calculations?
Elevation of the excavated main pool depth (bottom of sediment
201removal) (fmsl)
21 Elevation of the main pool bottom -(top of sediment removal) (fmsl)
22 Elevation of the bottom of the vegetated shelf (fmsl)
23 Elevation of the permanent pool (fmsl)
Yes
HRT
Yes
822.50
823.00
826.00
826.50
827.00
24
Elevation of the top of the vegetated shelf (fmsl)
25
Elevation of the temporary pool (fmsl)
828.50
26
Surface area of the main permanent pool (square feet)
30040:1
87015 cf
27
Volume of the main permanent pool (cubic feet)
28
Average depth of the main pool (feet)
3.13 ft
29
Average depth equation used
Equation 3
30
If using equation 3, main pool perimeter (feet)
796.0 ft
31
If using equation 3, width of submerged veg. shelf (feet)
3.0 ft
32
Volume of the forebay (cubic feet)
14313 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)
29521 cf
36
Is the outlet an orifice or a weir?
Orifice
37
If orifice, orifice diameter (inches)
3 in
38
If weir, weir height (inches)
N/A
39
If weir, weir length (inches)
N/A
40
Drawdown time for the temporary pool (days)
3.8
41
Are the inlet(s) and outlet located in a manner that avoids short-
circuiting?
Yes
et
A -re berms or baffles provided to improve the flow patIV
No
2:57 PM 12/3/2019

WET POND
Depth of forebay at entrance (inches)
54 in
r45
Depth of forebay at exit (inches)
54 in
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?
Does the pond minimize impacts to the receiving channel from the 1-
yr, 24-hr storm?
Yes
49
Yes
No
50
Are fountains proposed? (If Y, please provide documentation that
MDC(9) is met.)
Is a trash rack or other device provided to protect the outlet system?
Are the dam and embankment planted in non -clumping turf grass?
51
Yes
52
Yes
53
L4
Species of turf that will be used on the dam and embankment
No Mow Seed Mix
as a planting plan been provideprovidea for the vegetate shelf?
es
ADDITIONAL
INFORMATION
Please use this space to provide any additional information about the
55 wet pond(s):
Wet Pond 4 2:57 PM 12/3/2019

STORMWATER WETLAND
1 Drainage area number
2 1 Design volume of SCM (cu it)
3ENERAL MDC FROM 02H .1050
2
T 2822 cf
Is the SCM sized to treat the SW from all surfaces at build -out?
1 Is the SCM located away from contaminated soils?
What are the side slopes of the SCM (H:V)?
Does the SCM have retaining walls, gabion walls or other engineered side
slopes?
Are the inlets, outlets, and receiving stream protected from erosion (10-year
storm)?
Is there an overflow or bypass for inflow volume in excess of the design volume?
What is the method for dewatering the SCM for maintenance?\
Yes
4
Yes
5
3:1
6
No
7
Yes
8
9
No
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
13 1
If the SCM is on a single family lot, does (will?) the plat comply with General
MDC (10)?
Is there an O&M Agreement that complies with General MDC (11)?
No
14
Yes
15
Is there an O&M Plan that complies with General MDC (12)?
Yes
16
Does the SCM follow the device specific MDC?
Was the SCM designed by an NC licensed professional?
Yes
17
Yes
STORMWATER WETLAND MDC FROM 02H .#054
18 jAre the inlet(s) and outlet located in a manner that avoids short-circuiting?
19 jAre berms or baffles provided to improve the flow path?
Yes
Yes
20 Does the orifice drawdown from below the top surface of the permanent pool? Yes
Does the wetland minimize impacts to the receiving channel from the 1-yr, 24-hr
21 storm? Yes
22 Is a trash rack or other device provided to protect the outlet system? Yes
Elevations
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
Elevation, peak attenuation above temporary pool (if applicable) (fmsl)
Elevation, temporary pool (top of the temporary inundation zone) (fmsl)
813.00
Elevation, permanent pool (top of the shallow water zone) (fmsl)
812.00
Elevation, bottom of shallow water zone (fmsl)
811.50
Elevation, bottom of forebay deep pool at deepest point (at forebay entrance)
(fmsl)
Elevation, bottom of forebay deep pool at shallowest point (at forebay exit) (fmsl)
810.00
810.00
Elevation, bottom of non-forebay deep pool at deepest point (fmsl)
810.00
g Zones
Area, total surface area of the SW wetland at temporary pool elev. (sq ft) 4,670.00
Area, temporary inundation zone at temporary pool elev. (sq ft) 1,710.00
Area, shallow water zone at temporary pool elev. (sq ft) 1,690.00
Area, forebay at temporary ool elev. (sq ft 680.00
Area, non-forebay deep pool at temporary ool elev .(sq ft 590.00
Percent area provided, temporary inundation zone should be 30-45% 37%
Percent area provided, shallow water zone should be 35-45% 36%
Percent area provided, deep pool(forebay) should be 10-15% 15%
Percent area provided, deep pool (non-forebay) (should be 5-15%) 13%
2:17 PM 12/3/2019

STORM`IVATER WETLAND
Depths and Outlet
39 Peak attenuation depth above temporary inundation zone (inches)
40 I -Temporary inundation zone depth temporary pool to permanent pool) (inches)
41 Shallow water zone depth(permanent pool to bottom of wetland) (inches)
Depth, forebay at entrance (permanent pool to bottom of forebay entrance)
42 inches
43 Depth, forebay at exit (permanent pool to bottom of forebay exit) (inches)
44 Depth, non-forebay deep pools (permanent pool to deep pool bottom) (inches
45 If there is an orifice, diameter (inches)
46 If there is a weir, weir height inches
47 If there is a weir, weir length inches
48 Drawdown time for the temporary pool (days)
ill and Plants
49 ISoil amendment depth (inches)
50 lHas a soil amendment specification been provided?
51 Has a landscaping plan that meets SW Wetland MDC (12) been provided?
52 Number of plants per 200 square feet (#) in the shallow water zone:
Does the temporary inundation zone planting comply with SW Wetland MDC
53 (14)?
Are the dam structure and temporary fill slopes planted in non -clumping
54 turfgrass?
55 lWill cattails be planted in the wetland?
)DITIONAL INFORMATION
Please use this space to provide any additional information about the
56
stormwater wetland(s):
11 in
__12 in
6 in
24 in
24 in
24 in
1 in
12 in
12 in
2.2
4 in
Yes
Yes
50
Yes
Yes
go —
Wetland 6 2:57 PM 12/3/2019