20131013 Ver 1_More Info Received_20131011 (14)

Strickland, Bev
From: Devane, Boyd
Sent: Tuesday, November 12, 2013 3:51 PM
To: Strickland, Bev
Subject: FW: Tom Allen Driveway 13 -1013
From: Devane, Boyd
Sent: Friday, October 11, 2013 8:46 AM
To: Kevin Varnell
Subject: Re: Tom Allen Driveway
Thanks. That was very helpful. I am on vacation until Tuesday and get projects confused. However I didn't see any
runoff map nor see and runoff calculations unless they were on the one site plan that I saw. The second page was only
basics about erosion control. Therefore if u email me info I will look at it on Tuesday .
Sent from my iPhone
On Oct 11, 2013, at 7:59 AM, "Kevin Varnell" < kvarnell @stocksengineering.com> wrote:
Boyd,
See my responses below to your comments for the Tom Allen Driveway.
Show on a drawing what the final elevations and slope of the road will be so I will know what
flows are going across the buffers at the crossing and what flows are diffused across the
landscape
The single family residential driveway will be constructed at grade. So the proposed contours
will match the existing for the centerline of the road except for the stream crossing where the
contours are shown. The fill side of the road will not have a ditch. The water will simply sheet
flow off the road and down the hill. For the cut side of the road, which is on the left prior to
getting to the creek crossing, the ditch is created by the fill and therefore will go straight into
the stream.
Show on a drawing if swales or ditches will line the road or if runoff from the road will flow in a
diffuse manner across the landscape.
See comment above.
3. Show on a drawing the drainage area that is contributing stormwater to the buffer area.
There should have been calculations with a Runoff Map submitted. If you do not have the
calculations or the Runoff Map, let me know and I will email one to you.
4. Calculation of velocity of stormwater going across the buffer and how the Diffuse Flow
Requirement of the Tar - Pamlico buffer rules will be met. The Tar - Pamlico buffer rules can be
found at this link. DOC
The Runoff Map may be useful for you here as the largest drainage area I have is 2.33 Acres. For
a non - erosive flow ( <2 ft /s), it only has to spread out 10 feet. For the cut areas the ditch created

by the fill slope will go straight into the stream with the drainage area being 7% impervious. I
don't really have many other options here as the driveway has to go over the culvert.
If you have any other questions, do not hesitate to let me know.
Sincerely,
Stocks Engineering, PA
Y. <e-� %la, X
Kevin Varnell