HomeMy WebLinkAboutSW6240803_Supplement-EZ Form_20240916 Red triangles at the upper right hand corner indicate design comments
Please complete the yellow shaded items.
OFWATF9
NCDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WETLAND SUPPLEMENT
This form must be filled out,printed and submitted.
The Required Items Checklist(Part Ill)must be printed,filled out and submitted along with all the required information.
I. PROJECT INFORMATION
Project name HIES EASTOVER
Contact name WILLIAM CLAYTON,PE
Phone number 828-455-3456
Date
Drainage area number 1
II. DESIGN INFORMATION
Site Characteristics
Drainage area 187,582.00 ft2
Impervious area 174,894.00 ft2
Percent impervious 93.2% %
Design rainfall depth 1.00 inch
Peak Flow Calculations
1-yr,24-hr rainfall depth 3.02 in
1-yr,24-hr intensity 0.13 in/hr
Pre-development 1-yr,24-hr runoff 0.39 ft3/sec
Post-development 1-yr,24-hr runoff 0.53 ft3/sec
Pre/Post 1-yr,24-hr peak control 0.14 ft3/sec
Storage Volume: Non-SA Waters
Minimum required volume 13,114.00 ft3
Volume provided(temporary pool volume) 15,000.00 ft3 OK
Storage Volume: SA Waters Parameters
1.5"runoff volume ft3
Pre-development 1-yr,24-hr runoff volume ft3
Post-development 1-yr,24-hr runoff volume ft3
Minimum volume required ft3
Volume provided ft3
Outlet Design
Depth of temporary pool/ponding depth(DPlants) 12.00 in OK
Drawdown time 2.70 days OK
Diameter of orifice 2.00 in OK
Coefficient of discharge(CD)used in orifice diameter
calculation 0.60(unitless)
Driving head(Ho)used in the orifice diameter calculation 0.33 ft Provide calculations to support this driving head.
Form SW401-Wetland-Rev.6-1 1/16/09 Parts I and II.Project Design Summary,Page 1 of 3
Surface Areas of Wetland Zones
Surface Area of Entire Wetland 15,000.00 ft2 OK
Shallow Land 5,000.00 ft2 OK
The shallow land percentage is: 33% %
Shallow Water 6,000.00 ft2 OK
The shallow water percentage is: 40% %
Deep Pool
Forebay portion of deep pool(pretreatment) 1,500.00 ft2 OK
The forebay surface area percentage is: 10% %
Non-forebay portion of deep pool 1,500.00 ft2 OK
The non-forebay deep pool surface area percentage is: 10% %
Total of wetland zone areas 14,000.00 ft2 Enter data into the shaded cells in this section.
Add or subtract the following area from the zones -1,000.00 ft2
Topographic Zone Elevations
Temporary Pool Elevation(TPE)
Shallow Land(top) 127.50 ft amsl
Permanent Pool Elevation(PPE)
Shallow Water/Deep Pool(top) 127.50 ft amsl
Shallow Water bottom 127.00 ft amsl
Most shallow point of deep pool's bottom 125.00 ft amsl
Deepest point of deep pool's bottom 125.00 ft amsl
Design must meet one of the following two options:
This design meets Option#1,
Top of PPE is within 6"of SHWT,If yes: (Y or N)
SHWT(Seasonally High Water Table) 124.80 ft amsl OK
This design meets Option#2, (Y or N)
Wetland has liner with permeability<0.01 in/hr,If yes:
Depth of topsoil above impermeable liner in
Topographic Zone Depths
Temporary Pool
Shallow Land 0.00 in
Permanent Pool
Shallow Water 6.00 in OK
Deep Pool(shallowest) 30.00 in OK
Deep Pool(deepest) 30.00 in OK
Planting Plan
Are cattails included in the planting plan? N (Y or N) OK
Number of Plants recommended in Shallow Water Area:
Herbaceous(4+cubic-inch container) 1,500
Number of Plants recommended in Shallow Land Area:
Herbaceous(4+cubic-inch container),OR 1,250
Shrubs(1 gallon or larger),OR 200
Trees(3 gallon or larger)and Herbaceous(4+cubic-inch) 25 and 1,000
Number of Plants provided in Shallow Water Area:
Herbaceous(4+cubic-inch container)
Number of Plants provided in Shallow Land Area:
Herbaceous(4+cubic-inch container)
Shrubs(1 gallon or larger)
Trees(3 gallon or larger)and
Grass-like Herbaceous(4+cubic-inch)
Form SW401-Wetland-Rev.6-11/16/09 Parts I and II.Project Design Summary,Page 2 of 3
Additional Information
Can the design volume be contained? Y (Y or N) OK
Does project drain to SA waters? If yes, N (Y or N) Excess volume must pass through filter.
What is the length of the vegetated filter? ft
Are calculations for supporting the design volume provided in the (Y or N) OK
application?
Is BMP sized to handle all runoff from ultimate build-out? Y (Y or N) OK
Is the BMP located in a recorded drainage easement with a (Y or N) OK
recorded access easement to a public Right of Way(ROW)?
The length to width ratio is: 1.78 :1 OK
Approximate wetland length 160.00 ft
Approximate wetland width 90.00 ft
z This approx.surface area is within this number of square feet
Approximate surface area using length and width provided 14,400.00 ft of the entire wetland surface area reported above:
Will the wetland be stabilized within 14 days of construction? Y (Y or N) OK
Form SW401-Wetland-Rev.6-11/16/09 Parts I and II.Project Design Summary,Page 3 of 3