SW6240503_Supplement-EZ Form_20240606

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Sawyer Ridge
2 Project Area(ac) 8.13
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0
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) 0
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
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 Name and Title: David Arnold,PE/Owner
28 Organization: Arnold Land Design,PLLC
29 Street address: 113 Yosemite Court
30 City,State,Zip: Holly Springs,NC 27540
31 Phone number(s): 919-630-2552
32 Email: [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.
Designer
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DRAINAGE AREAS
Is this a high density project?
1No
2 If so,number of drainage areas/SCMs _
3 Does this project have low density areas? Yes
_
4 If so,number of low density drainage areas _ 1
Is all/part of this project subject to previous rule
5 versions? No
CLICK TO LOAD FORM

LOW DENSITY
DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H.1003 1 Is project below density thresholds set forth in the applicable stormwater rule? Yes
2 Does project maximize dispersed flow and minimize channelization of flow? Yes
3 Has the use of piping been minimized per.1003(2)(c)? Yes
4 Side slopes of the vegetated conveyances(H:V) 2:1
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 2.18
6 Are curb outlet swales proposed? No
7 Maximum longitudinal slope of curb outlet swale(s)(%)
8 Bottom width of curb outlet swale(s)(feet)
9 Maximum side slope of curb outlet swale(s)(H:V)
10 Minimum length of curb outlet swale(s)(feet)
11 Are treatment swales used instead of curb outlet swales?
12 Is stormwater released at the edge of the setback as dispersed flow?
13 Have stormwater outlets been designed to prevent downslope erosion? Yes
14 Are variations to rule.1003 proposed? No
ADDITIONAL INFORMATION
15 Please use this space to provide any additional information about this low density project:
Project is for 12 residential lots along 1 proposed NCDOT street.A portion of the street will have roadside swales and the
remainder will sheet flow. Side slopes of swales are 3:1 foreslope and 2:1 backslope to meet NCDOT requirements and keep in
the right of way.Calculations have been provided and ditches will be lined to prevent erosion. American Excelsior Curlex 1 has
an allowed maximum permissible velocity of 7 fps and shear stress of 1.75 psf.Swales have been designed for 10-year flow and
to not overtop.Lots will sheet flow as this project is located at the top of a ridge. C factors for calculating flow have been
assumed as overly conservative since exact built upon areas are not knows at this time. Maximum per lot will be 5,500 sf to
stay under 24%impervious.
Drainage Pervious
Swale BUA Q Slope V,ii,w V,,,,,i Flow depth
Area area
(ac) (cfs) (%) (fps) (fps) (ft)
(ac) (ac)
1 1.76 TBD TBD 0.50 6.23 0.006 7.00 2.18 1.20
2 0.80 TBD TBD 0.80 2.27 0.006 7.00 1.69 0.82
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