20080595 Ver 1_Information Letter_20080401

[Fwd: B-4540 Little Fishing Creek Permit Impacts]
Subject: [Fwd: B-4540 Little Fishing Creek Permit Impacts]
From: Chad Goggins <[e-mail]>
Date: Mon, 07 Apr 2008 10:51:09 -0400
To: Rob Ridings <[e-mail]>
Rob,
This is the response I got back from the consultant about
stormwater issue on bridge.
Your thoughts?
Chad Goggins
NCDOT Div. 4
Environmental Officer
252-296-3532
Subject: B-4540 Little Fishing Creek Permit Impacts
From: "Rice, James R." <[e-mail]>
Date: Fri, 4 Apr 2008 14:04:55 -0500
To: <[e-mail]>
CC: "Miller, Vickie M" <[e-mail]>, "Henderson, Jonathan"
<[e-mail]>
Chad, I just wanted to follow up on the permit impact sheets for B-4540 over Little Fishing Creek. The only
drainage required for the bridge was deck drains. The allowable spread on the bridge required the use of deck.
drains and the bypass did not warrant a box at the end. We did note on the bridge plans as well as the roadway
plans that none of the deck drains will discharge over the open water. We also looked at collecting the drains into
a system and discharging into a bmp. This project is simply a bridge replacement and bridge maintenance has
requested that we keep all disturbance within the existing right of way. The existing roadway fill slopes tie down
roughly at the existing right of way line, so there wasn't any room to place any stormwater treatment devices. We
then considered the existing stormwater conditions. Currently, the water collected from the bridge runs along the
bridge rail, then runs down the fill slope in a ditch that was scoured out, and finally discharges into the stream.
The proposed bridge will have 4" scuppers placed in the bridge rail at 5.5' spacing. The good thing about the short
spacing on the scuppers is that there is not a lot of discharge from each scupper, approximately 0.006 cfs in the
design storm. This proposed design also eliminates the water collected on the bridge from concentrating into a
flow that would create a ditch by scour. If you have any further questions or concerns please don't hesitate to call.
Thanks.
James
919-232-6621
James R. Rice, PE
HDR Engineering, Inc. of the Carolinas
3733 National Drive Suite 207 ~ Raleigh, NC ~ 27612
Phone: [phone] ~ Fax: [phone]
Email: ,iam.es,rce(h?hdiinc.com
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