20140770 Ver 1_Emails_20141017

Strickland, Bev
From: Devane, Boyd
Sent: Friday, March 27, 2015 11:11 AM
To: Strickland, Bev
Subject: FW: Beaverdam Road project # 14 -0770
Attachments: Supplement-Dry Ext Det Basin_Rev.3_Locked.xls; Supplement-FiltStripLevelSpread-
Rev.10_29J u ne2012.xls
Please file this email and attachments in the Beaverdam Rd project 14 -0770
From: Wanda Austin [mai Ito: wa ndajoycea usti n(d)a ma il.com]
Sent: Friday, October 17, 2014 6:22 AM
To: Devane, Boyd
Cc: Barnett, Kevin; Fox, Tim
Subject: Re: Beaverdam Road project # 14 -0770
Good morning. It is unfortunate that you have been unable to understand the information submitted. The forms
mentioned above were submitted with the original PCN in July. I do not know why you were not given the
complete PCN package. I have attached the files to the email. The project for Phase I is contained within the
drainage area on the plan submitted; there is no other drainage area except the one shown on the plan.
The review of this permit seems to be unnecessarily delayed. All other agencies have approved the permit. If
you would like to discuss the permit, I will be available at 3:00 PM today. My cell phone number is 828 -342-
5079.
Thank you
On Tue, Oct 14, 2014 at 4:19 PM, Devane, Boyd <boyd.devanegncdenr.gov> wrote:
Wanda, I've only recently had time to look at the Beaverdam project. I've been overwhelmed and have had to
deal with many projects. Unfortunately, I'm still having trouble understanding the exact areas that will be
treated by the dry detention basin. You said that the project only had one drainage area. Maybe you could
better define what the "project area" is. Maybe provide a drawing that only shows the area draining to the dry
basin. In our earlier correspondence, I emphasized the need to see the drainage area going to the BMP. Maybe
I should have said that we needed to see the boundary area perimeter. This is a basic requirement of all
stormwater plans reviewed by the Division. You did send a revised drawing with a better "drainage area"
overlay. However, I still have some basic questions. The perimeter of the drainage area is not easy to
determine on the paper copies. I want to be able to look at the drawing and see very visible drainage and sub -
drainage areas, if sub drainage areas are available. Then I need to know the sq feet of the area or areas draining
to the stormwater treatment system and the amount of that which is impervious. I need to see your calculation
of volumes for the design storm. The Supplement Sheet for a dry detention BMP provides a list of things that
we need to review. Look under the "BMP Supplement forms" at http: / /portal.ncdenr.org /web /lr /bmp- manual
. At the bottom of the page, you will see a "Required Items Checklist." . Filling out these is not mandated but
certainly helps facilitate our review.
I'm sorry that we have obviously misunderstood each other on what is needed to enable us to review the
capability of the treatment system to treat the stormwater. I will be out of the office this Wednesday and

Thursday but will return Friday. Perhaps if we went over these issues over the phone first, we can achieve a
more expeditious resolution of these issues. Is there any time Friday that you can be available for us to talk?
PS. The PCN indicated that the impervious area of the project was 18 %. Because of that, I assumed that your
project was low density but you were installing the dry detention/LS device for some other reason. Is the
amount of impervious in the area draining to the dry basin really 18 %? Does that mean the expected built -out
to the basin will be 18 %? If that is the case, we may can find an easier way to meet the 401 stormwater
requirements.
N

Permit No.
(to be provided by DWQ)
t� A Q
STORMWATER MANAGEMENT PERMIT APPLICATION FORM >_
NCDENFt a
401 CERTIFICATION APPLICATION FORM
DRY EXTENDED DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part III) must be printed, filled out and submitted along with all the required information.
L I1'R0,J E'CT I N F0RMATI ON
Project name Beaverdam Road—Harley Enterprises
Contact person Adam King
Phone number (828) 593 -8876
Date 26- Jun -14
Drainage area number 1
Site Characteristics
Drainage area
339,768.00
ft2
Impervious area
56,628.00
ft2
% Impervious
0.17
Design rainfall depth
1.00
in
Peak Flow Calculations
1 -yr, 24 -hr rainfall depth
2.36
in
Rational C, pre - development
0.20
(unitless)
Rational C, post - development
0.32
(unitless)
Rainfall intensity: 1 -yr, 24 -hr storm
0.10
in /hr
Pre - development 1 -yr, 24 -hr peak flow
0.16
ft3 /sec
Post - development 1 -yr, 24 -hr peak flow
0.25
ft3 /sec
Pre /Post 1 -yr, 24 -hr peak control
0.09
ft3 /sec
Storage Volume: Non -SA Waters
Minimum required volume
5,663.00
ft3
Provided volume
71200.00
ft3
OK
Sediment storage volume provided
1,800.00
ft3
OK
Storage Volume: SA Waters
1.5" runoff volume
ft3
Pre - development 1 -yr, 24 -hr runoff volume
ft3
Post - development 1 -yr, 24 -hr runoff volume
ft3
Minimum required volume
ft3
Provided volume
ft3
Sediment storage volume provided
ft3
Basin Design Parameters
Drawdown time
5.00
days
OK
SHWT elevation
2630.00
fmsl
Basin bottom elevation
2638.00
fmsl
OK
Storage elevation
2641.00
fmsl
Basin side slopes
3.0
:1
OK
Top elevation
2642.00
fmsl
OK
Freeboard provided
1.00
ft
OK
Basin Bottom Dimensions
Basin length
160.00
ft
Basin width
30.00
ft
Length to width ratio
5.30
:1
OK
Form SW401 -Dry Extended Detention Basin -Rev.3 Parts I. & II. Design Summary, Page 1 of 2

Additional Information
Total runoff volume captured by basin
Forebay provided
Is basin in a recorded drainage easement?
Does basin capture all runoff at ultimate build -out?
Is a sediment depth indicator included?
Does the basin include a drain?
4.23 ac -in
N (Y or N)
Y (Y or N)
Y (Y or N)
Y (Y or N)
Y (Y or N)
Permit No.
Forebay is not required
(to be provided by DWQ)
Form SW401 -Dry Extended Detention Basin -Rev.3 Parts I. & II. Design Summary, Page 2 of 2

hL
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER - VEGETATED FILTER STRIP (LS -VFS) SUPPLEMENT
This form must be completely filled out, printed, initialed, and submitted.
I. PROJECT INFORMATION
OF WAT��
O G
>
U
1��Irlp
Project name
Contact name
Phone number
Date
Drainage area number
Beaverdam Road—Harley Enterprises
Adam King
(828) 593 -8876
June 26, 2014
1
111i DESIGN INFORMATION
The purpose of the LS -VFS
Pollutant removal: 40% TSS, 30% TN, 35% TP
Stormwater enters LS -VFS from
The drainage area
Type of VFS
Engineered filter strip (graded & sodded, slope < 8 %)
Explanation of any "Other" responses above
If Stormwater Enters the LS -VFS from the Drainage Area
Drainage area
339,768
ft2
Impervious surface area
56,628
ft2
Percent impervious
16.67
%
Rational C coefficient
0.32
Peak flow from the 1 in /hr storm
2.50
cfs
Time of concentration
5.00
min
Rainfall intensity, 10 -yr storm
6.5
in /hr
Peak flow from the 10 -yr storm
16.22
cfs
Design storm
10 -year storm
Maximum amount of flow directed to the LS -VFS
10
cfs
Is a flow bypass system going to be used?
Y
(Y or N)
Explanation of any "Other" responses above
If Stormwater Enters the LS -VFS from a BMP
Do not complete this section of the form.
Type of BMP
Pick one:
Peak discharge from the BMP during the design storm
cfs
Peak discharge from the BMP during the 10 -year storm
cfs Do not complete this section of the form.
Maximum capacity of a 100 -foot long LS -VFS
10
cfs
Peak flow directed to the LS -VFS
cfs Do not complete this section of the form.
Is a flow bypass system going to be used?
(Y or N)
Explanation of any "Other" responses above
Form SW401 - LS -VFS - 29June2012 - Rev.10 page 1 of 3

LS -VFS Design
Forebay surface area
Depth of forebay at stormwater entry point
Depth of forebay at stormwater exit point
Feet of level lip needed per cfs
Computed minimum length of the level lip needed
Length of level lip provided
Width of VFS
Elevation at downslope base of level lip
Elevation at the end of the VFS that is farthest from the LS
Slope (from level lip to the end of the VFS)
Are any draws present in the VFS?
Is there a collector swale at the end of the VFS?
Bypass System Design (if applicable)
Is a bypass system provided?
Is there an engineered flow splitting device?
Dimensions of the channel (see diagram below):
M
B
W
y (flow depth for 10 -year storm)
freeboard (during the 10 -year storm)
Peak velocity in the channel during the 10 -yr storm
Channel lining material
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Explanation of any "Other" responses above
11,325
sq ft Forebay is adequately sized.
18
in
6
in Depth is appropriate.
10
ft/cfs
100
ft
100
ft
30
ft
2,644.00
fmsl
2,642.00
fmsl
6.67
%
N
(Y or N) OK
(Y or N)
Y (Y or N)
N (Y or N)
4.00
ft
0.00
ft
10.50
ft
0.30
ft
1.00
ft
6.22
ft/sec
Grass
N (Y or N)
Y (Y or N)
r
r� r
-
't
w �
B
N4
Form SW401 - LS -VFS - 29June2012 - Rev.10 page 2 of 3

EDIT Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to indicate the
following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a requirement has not been
met, attach justification.
Requried Item:
1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Forebay (if applicable),
- High flow bypass system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW), and
- Boundaries of drainage easement.
2. Plan details (1" = 30' or larger) for the level spreader showing:
- Forebay (if applicable),
- High flow bypass system,
- One foot topo lines between the level lip and top of stream bank,
- Proposed drainage easement, and
- Design at ultimate build -out.
3. Section view of the level spreader (1" = 20' or larger) showing:
- Underdrain system (if applicable),
- Level lip,
- Upslope channel, and
- Downslope filter fabric.
4. Plan details of the flow splitting device and supporting calculations (if applicable).
5. A construction sequence that shows how the level spreader will be protected from
sediment until the entire drainage area is stabilized.
6. If a non - engineered VFS is being used, then provide a photograph of the VFS showing
that no draws are present.
7. The supporting calculations.
8. A copy of the signed and notarized operation and maintenance (0 &M) agreement.
Initials Page or plan sheet number and any notes:
Form SW401 - LS -VFS - 29June2012 - Rev.10 page 3 of 3