20160325 Ver 2_RE Bluewater Rise_20161214

Strickland, Bev
From:Bobby Billingsley, PE <[e-mail]>
Sent:Wednesday, December 14, 2016 11:13 AM
To:Scarbraugh, Anthony
Subject:RE: Bluewater Rise
Attachments:BluewaterRise_NWP29_Sheet6.pdf
Anthony please see the attached for this discussion. Here are some comments:

1.I talked with John about this. What we did is add a sheet (Sheet 6 of 6) to the plan set. This addresses level flow

spreader weirs on the southeast and southwest quadrants. The northeast and northwest quadrants don’t have
any concentrated flows coming into them. One the northeast, there is a fill slope only with no ditch. On the
northwest, the ditch goes through a small stormwater attenuation basin with slow release. At the crossing
itself, it is just a fill slope as shown.
2.I calculated the flow from the southeast and southwest quadrant. On the southeast, the drainage area

contributing to the proposed ditch is only about a ¼ acre. On the southwest, the drainage area contributing is
only about 1/2 an acre, so both are very small. Approximately a third of the drainage areas is to be
impervious. Assuming this, and a 10 yr storm, 5 min concentration of 8.78 in/hr, I roughly and conservatively
calculate a cfs of 1.84 cfs, so around 2 cfs contributing to the level spreader weirs.
3.So with 2 cfs for the 10 yr storm (less than the 1 yr), we thought that 15’ spreaders were acceptable for this. We

have typically done this with small swales and treated timber weirs as shown on the attached detail. We also
details full sodding on the slope where the flow is to be sheet-flowed out across off the weir.

Please review this plan and the above and let me know if this is acceptable or not, or what you need as far as hard
copies or any further documentation on this.

Thanks,

Bobby Billingsley, PE
[e-mail]
ThomasEngineeringPA.com

Phs. Address: 1316-B Commerce Drive
New Bern, NC 28562
Mail Address: PO Box 1309
New Bern, NC 28563
Office : 252.637.2727
Mobile: 252.671.2408
Fax: 252.636.2448

From: Scarbraugh, Anthony \[mailto:[e-mail]\]
Sent: Friday, December 02, 2016 1:14 PM
To: Bobby Billingsley, PE <[e-mail]>
Subject: Re: Bluewater Rise

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Mr. Billingsley,

That will be sufficient.

Anthony
From: Bobby Billingsley, PE <[e-mail]>
Sent: Friday, December 2, 2016 9:16:42 AM
To: Scarbraugh, Anthony

Subject: RE: Bluewater Rise

I think I should be able to do this, just haven’t gotten a change to get into it yet. I can bring the road into a small level
spreader/veg filter before it enters the buffers to dissipate.

Thanks,

Bobby Billingsley, PE
[e-mail]
ThomasEngineeringPA.com

Phs. Address: 1316-B Commerce Drive
New Bern, NC 28562
Mail Address: PO Box 1309
New Bern, NC 28563
Office : 252.637.2727
Mobile: 252.671.2408
Fax: 252.636.2448

From: Scarbraugh, Anthony \[mailto:[e-mail]\]
Sent: Friday, December 02, 2016 8:50 AM
To: Bobby Billingsley ([e-mail]) <[e-mail]>
Subject: Bluewater Rise

Mr. Billingsley,

If you can demonstrate that the stormwater entering the buffer from above the crossing is being treated or diffuse flow
is being achieved then the crossing as currently designed will be sufficient to meet the buffer rule requirements.

Anthony Scarbraugh

Anthony Scarbraugh
Environmental Senior Specialist
Division of Water Resources – Water Quality Regional Operations
Department of Environmental Quality

252 948 3924 office
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[e-mail]

943 Washington Square Mall
Washington, NC 27889

Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

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