SW6200904_Revised EZ Supplement Form_20220823

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1
Project Name
Timberland Ranch
2
Project Area (ac)520.306
3
Coastal Wetland Area (ac)
-
4
Surface Water Area (ac
5
Is this project High or Low Density?
Low
6
Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H .1003(4
7
Width of vegetated setbacks provided feet
N/A
8
Will the vegetated setback remain vegetated?
N/A
_ _9
If BUA is proposed in the setback, does it meet NCAC 021-1.1003 4 (c-d)?
_
No
10
Is streambank stabilization proposed on this project?
No
NUMBER AND TYPE OF SCMs:
11
Infiltration System _
Bioretention Cell
8
12
0
0
13
Wet Pond
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
0
20
Disconnected Impervious Surface (DIS)
21
Treatment Swale
0
22
Dry Pond
0
23
StormFilter
0
24
Silva Cell
0
25
Ba filter
0
26
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title: _
Organization:
Street address:
City, State, Zip:
Phone numbers :
Email:
Carlo Pardo, PE
28
Bowman North Carolina, Ltd.
29
4006 Barrett Drive, Suite 104
30
Raleigh, NC 27609
31
919-553-6570
32
[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-
C.
Signature of Designer
Date

DRAINAGE AREAS
1
Is this a hi h density project?
No
2
If so, number of drainage areas/SCMs
0
3
Does this project have low density areas?
Yes
4
If so, number of low density drainage areas
8
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
LD 1
LD 2
LD 3
L 4
4
Type of SCM
Infiltration Trench
Infiltration Trench
Infiltration Trench
Infiltration Trench
5
Total drainage area (sq ft
22664530 sf
212925
80165
111705
185040
6
Onsite drainage area (sq ft
22664530 sf
212925
80165
111705
185040
7
Offsite drainage area (sq ft
8
Total BUA in project (sq ft
1009888 sf
113469 sf
48933 sf
81750 sf
117141 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
894000 sf
84000 sf
36000 sf
72000 sf
96000 sf
10permitting)
New BUA not on subdivided lots (subject to
s
115888 sf
29469 sf
12933 sf
9750 sf
21141 sf
11
Offsite BUA (sq ft
12
Breakdown of new BUA not on subdivided lots:
Parking (sq ft
Sidewalk (sq ft
6046 sf
4702 sf
1344 sf
Roof (sq ft
Roadway s ft
104497 sf
24767 sf
11589 sf
9750 sf
15796 sf
Future (sq ft
Other. please specify in the comment box
below (sq ft
5345 sf
5345 sf
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15permitting)
Existing BUA that will remain (not subject to
s ft
16
Existina BUA that is already permitted (sq ft
17
Existing BUA that will be removed (sq ft
18
Percent BUA
4%
53%
61%
73%
63%
19
Design storm (inches)
1.0 in
1.0 in
1.0 in
1.0 in
20
Design volume of SCM cu ft
9397 cf
4004 cf
6597 cf
9557 cf
21
Calculation method for design volume
1 Simple Method
Simple Method
Simple Method
Simple Method
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
CD-4 Other: Mail Kiosk Impervious

DRAINAGE AREAS
1
Is this a hi h density r9ject?
No
2
If so number of drainage areas/SCMs
0
3
Does this project have low density areas?
Yes
4
If so, number of low density drainage areas
8
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
LD 5
LD 6
LD 7
LD 8
4
Type of SCM
Infiltration Trench
Infiltration Trench
Infiltration Trench
Infiltration Trench
5
Total drainage area (sq ft
22664530 sf
96006
113711
182260
201552
6
Onsite drainage area (sq ft
22664530 sf
96006
113711
182260
201552
7
Offsite drainage area (sq ft
8
Total BUA in.project (sq ft
1009888 sf
81698 sf
24000 sf
134033 sf
167080 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
894000 sf
72000 sf
24000 sf
120000 sf
150000 sf
10permitting)
New BUA not on subdivided lots (subject to
s
Offsite BUA (sq ft
Breakdown of new BUA not on subdivided lots:
115888 sf
9698 sf
14033 sf
17080 sf
11
12
- Parkin S
-Sidewalk (sft
6046 sf
Roof (sq ft
Roadwa sq ft
104497 sf
9698 sf
14033 sf
17080 sf
Future (sq ft
Other, please specify in the comment box
below (sq ft
5345 sf
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15permitting)
Existing BUA that will remain (not subject to
s ft
16
Existing BUA that is already permitted (sq ft)
17
Existing BUA that will be removed (sq ft
18
Percent BUA
4%
85%
21%
74%
83%
19
Design storm inches
1.0 in
1.0 in
1.0 in
1.0 in
20
Design volume of SCM cu ft
6527 cf
2274 cf
10812 cf
13371 cf
21
Calculation method for design volume
Sim le Method
Simple Method
Simple Method
Simple Method
INFORMATION
Please use this space to provide any additional information about the
22 ldrainaq_e are_a(s):
LD4 Other: Mail Kiosk Impervious

INRLTRATION SYSTEM
' 1 Drainage area number 1 2 3___] 4
2 Minimum re uired treatment volume (cu ft) 9397 cf 4004 cf 6597 cf 9557 cf
GENERAL MDC FROM 02H .3050
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
Yes
Yes
Yes
4
Is the SCM located away from contaminated soils?
Yes
Yes
Yes
Yes
5
What are the side slopes of the SCM (H:V or enter "Vertical' for
trenches)?
3:1
3:1
3:1
3:1
6
Does the SCM have retaining walls, gabion walls or other engineered
side slopes?
No
No
No
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10 ear storm)?
Yes
Yes
Yes
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
Yes
Yes
Yes
9
jWhat is the method for dewatering the SCM for maintenance?
Pump (preferred)
Pump (preferred)
Pump (preferred)
Pump (preferred)
10
1 If applicable, will the SCM be cleaned out after construction?
Yes
Yes
Yes
Yes
11
Does the maintenance access comply with General MDC (8)?
Yes
Yes
Yes
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
Yes
Yes
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC 10 ?
N/A
N/A
N/A
NIA
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
Yes
Yes
Yes
15
Is there an O&M Plan that complies with General MDC (12)?
Yes
Yes
Yes
Yes
16
1 Does the SCM follow the devicespecific MDC?
Yes
Yes
Yes
Yes
17
lWas the SCM desi ned by an NC licensed p rofessional?
Yes
Yes
Yes
Yes
INFwatATION
5Y5TENt MQC FRom 0214 -insi
18
Proposed slope of the subgrade surface (%)
0%
0%
0%
0%
19
Are terraces or baffles provided?
No
No
No
No
20
Type of pretreatment:
Forebay
Forebay
Forebay
Forebay
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
Yes
Yes
Yes
22
JSHWT elevation fmsl
374.00
374.50
378,00
378.00
23
Depth to SHWT per soils report (in)
> 120
> 120
> 120
> 120
24
Ground elevation at boring in soils report (fmsl)
384.00
384.50
388.00
388.00
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
N/A
N/A
N/A
N/A
26
Soil infiltration rate in/hr
39.00
2.17
2.17
43.00
27
Factor of safety (FS) (2 is recommended):
2.00
2.00
2.00
2.00
29
1 Bottom elevation fmsl
380 ft
381 ft
384 ft 384 ft
30
Istorage elevation (fmsl)
384. ft
383. ft
386. It 387. f.
31
1 Bypass elevation (fmsl)
N/A
N/A
NIA NIA
For Basins Only
32 jBottom surface area (ft)
33 IStorage elevation surface area
34
Len th (ft)
163 ft
170 ft
291 ft
196 ft
35
Width (ft)
6 ft
5 ft
E ft
6 ft
36
Perforated pipe diameter, if applicable (inches)
N/A
NIA
N/A
N/A
37
Number of laterals
N/A
N/A
N/A
N/A
38
Total length of perforated piping
N/A
N/A
N/A
N/A
39
Stone type, if applicable
N/A
N/A
N/A
N/A
40
Stone porosity %
N/A
NIA
N/A
NIA
41
Is stone free of fines?
N/A
NIA
NIA
N/A
42
Is the stone wrapped in geotextile fabric?
Yes
Yes
Yes
Yes
43
Has at least one inspection port been provided?
Yes
Yes
Yes
Yes
Volumes/Drawdown
44 IDesign volume of SCM (cu ft) 9397 cf 4004 cf 6597 cf 9557 cf
45 1 Time to draw down (hours) 72 hrs 72 hrs 72 hrs 72 hrs
7d
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration systeln(s):
Infiltration 1 2:22 PM 11/2/2021

INFILTRATION SYSTEM
1 Dralnage area number 5 6 7 8
2 Minimum re uu-ed treatment volume(co ft 6527 cf 2274 cf 10812 cf 13371 cf
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
Yes
Yes
Yes
4
Is the SCM located away from contaminated soils?
Yes
Yes
Yes
Yes
5
What are the side slopes of the SCM (H:V or enter "Vertical' for
trenches)?
3:1
3:1
3:1
3:1
6
Does the SCM have retaining walls, gabion walls or other engineered
side slopes?
No
No
No
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10- ear storm)?
Yes
Yes
Yes
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
Yes
Yes
Yes
9
jWhat is the method for dewatering the SCM for maintenance?
Pump (preferred)
Pump (preferred)
Pump (preferred)
Pump (preferred)
10
If applicable, will the SCM be cleaned out after construction?
Yes
Yes
Yes
Yes
11
Does the maintenance access comply with General MDC (8)?
Yes
Yes
Yes
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
Yes
Yes
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC 10 ?
NIA
N/A
N/A
N/A
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
Yes
Yes
Yes
15
Is there an O&M Plan that complies with General MDC (12)?
Yes
Yes
Yes
Yes
16
IDoes the SCM follow the device specific MDC?
Yes
Yes
Yes
Yes
17
lWas the SCM designed by an NC licensedprofessional.?
Yes
Yes
Yes
Yes
INFILTRATION
SYMM MDC FROM 02H .1051
18
Proposed slape of the subgrade surface
0%
0%
0%
-:J
0%
19
Are terraces or bafflesprovided?
No
No
No
No
20
Type of pretreatment:
Forebay
Forebay
Forebay
I Forebay
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
Yes
Yes
Yes
22
JSHWT elevation fmsl)
379.50
373.50
379.00
387.00
23
1 Depth to SHWT per soils report (in)
> 120
> 120
> 121Y
> 120
24
Ground elevation at boring in soils report (fmsl)
389.50
383.50
389.00
297.00
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
N/A
N/A
N/A
N/A
26
Soil infiltration rate (in/hr)
5.50
2.17
2.17
2.17
27
Factor of safety (FS) (2 is recommended):
2.00
2.00
2.00
2.00
1 G1-#t-
29
Bottom elevation (fmsl)
384 ft
378 ft
383 ft
389 ft
30
Storage elevation fmsl
387. ft
380. ft
386. ft
392. ft
31
Bypass elevation (fmsl)
N/A
N/A
N/A
N/A
C- I1..h.
34
Length (ft)
190 ft
114 ft
338 ft
298 ft
35
Width (ft)
6 It
5 ft
7 ft
8 ft
36
Perforated pipe diameter, if applicable (inches)
NIA
N/A
N/A
N/A
37
Number of laterals
NIA
N/A
N/A
N/A
38
Total length of perforated piping
N/A
N/A
N/A
N/A
39
Stone type, if applicable
N/A
N/A
N/A
N/A
40
Stoneporosity (%)
N/A
N/A
N/A
N/A
41
Is stone free of fines?
N/A
N/A
N/A
N/A
42
Is the stone wrapped in geotextile fabric?
Yes
Yes
Yes
Yes
43
Has at least one inspection port been provided?
Yes
Yes
Yes
Yes
Volvmea(Drawdown
44 Desi n volume of SCM (cu ft) 6527 cf 2274 cf 10812 cf 13371 cf
45 1 Time to draw down hours 72 hrs 72 hrs 72 hrs 72 hrs
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration system(s):
Infiltration 2
2:22 PM 11/2/2021

LOW DENSITY
7ESIGN REQUIREMENTS FOR LOW DENSITY S FROM 02H 1003
1
is project below density thresholds set forth In theapplicablestormwater rule?
Yes
2
Does project maximize dispersed FlOw and minimize rhannelization of flow?
Yes
Yes
3
Has the use of piping been minimized per .1003(2)(c)?
sf
4
Side slopes of the vegetated conveyances (H:V)
3.71
5
Maximum velocity In the vegetated conveyances during the 10-year storm?
No
6 Are curb outlet swales proposed?
7
Maximum Ionghudinal slope of curb outlet swales) (%)
_
8
Bottom width of curb outlet swele(s) (feel)
9
Maximum side slope of nub outlet swales) (H:V)
_
10
Minimum length of curb outlet swales) (feet)
-
11
Are treatment swales used instead of curb outlet swales?
12
Is stormwater released at the edge of the setback as dispersed flow?
yes
13
14
Have sWrnwaler outlets been designed to prevent d_ownslope erosion?
Are variations to rule 1003 proposed? T
Yes
No
ADDITIONAL INFORMATION
15 please use this space to provide any additional information about this low density project:
Swale
0
Drainage Pervious
BUA O Slope V„a, � V� � Flow depth
Arse (ae) area C (efs) (%1 (hft) ups) (ft)
sac ac
1
2
S
4
6
11
7
_ 8
9
0.17 0.15
1.72 0.21
0.67 0.12
7.81 0.24
2.85 0.37
0.32 0.25
8.39 0.08
- 0.38 - - - 0.08
0,02
1.51
0.52
-1.57
0.80
0.30
0.80 _
0.30
0.30
0.80
- 0.30
1.10
4.12
-4_06
1_87�
6.83
2.02
20.07
2.97 3.00
L- 2297 4.00
2,97 -1 4.00
0.94 4.00
1-34 4-00
1-34 3-00
0.92 4.00
0.92 3.111
0.50 3.00
2.62
3.71
-3.71
3.47
0.25
0,47
0.47
0.94
2.49
0.07 _
8.32
3.15
0.71
2.31
CiAl
3.51
0.98
0.31
0.80
Z44
2.09
0.48
0.93 -
5.52
0.15
5.37
0.30
13.20
2.52
10
0.33
0.07
0,27
0.80
2.13
0.50
2.00 -
1.61
0.52-�
11
12
- - --
14
18
17
18
4ti
20
I
21
_
- 23-
24
--
25
^�
26
27
-
28
--
-
29
30
M