HomeMy WebLinkAbout20140657 Ver 1_More Info Received_20140721Homewood, Sue
From: Kevin Tweedy < eprusaoet>
Sent: Sunday, July 20, 2014 9:51 PM
To: Homewood, Sue
Cc eperdue@eprusaoet
Subject: RE: Potato Creek
Attachments: Pump Around Exemption Request'AUeghany.docx
MM
We would like to request an exemption from the clewatering requirement of the GC standard language, for both our Dog
Creek and Potato Creek Projects in Alleghany County that have recently been submitted for permitting.
Please see attached request. Thanks, and please let me know if you need more information.
From: Homewood, Sue
Sent: Fhday,]uh 18, 2014 4:22 PM
To: Kevin Tweedy (ktweedy(cbeprusa. net)
Subject: Potato Creek
Hey Kevin,
The PCN for the Potato Creek project states "all work will be conducted in the wet (see attached pump-around diversion
exemption)" But I don't see anything attached that discusses the pump around diversion exemption. | just need a
justification as we did for the last few projects to show that you have good reason to work in the wet.
Thanks
Ps, | haven't looked at the other project that came in at the same time (in case that has the same issue you can send it
for both of them, just reference both projects so I know)
Sue Homewood
N[ DENRVVinston-Sa|em Regional Office
Division of Water Resources — Water Quality Programs
585 Waughtown Street
Winston-Salem, NC 27107
Voice: (336) 771-4964
FAX: (336) 771-4630
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed tothird parties.
REQUEST FOR PUMP - AROUND DIVERSION EXEMPTION
Dog Creek and Potato Creek Projects — Alleghany County
For small stream systems (< one square mile of drainage), pump- around systems are relatively simple to
install and can be effective for certain projects. For larger streams, like the Dog Creek and Potato Creek
Projects, pump- around systems require significant disturbance, equipment, and maintenance to
function as intended.
Numerous concerns have been raised over the past 10 years (the approximate period that pump- around
systems have been required for in- channel work) about the use of these systems. These are
summarized in the bullets that follow:
• Installation and maintenance of a pump- around system can cause significant site disturbance,
considering the system is supposed to prevent erosion.
• In- channel stream restoration work primarily disturbs sediment that is already present in the
stream system as bed material. This material is naturally mobile during storm events. The goal
of sediment and erosion control practices is to prevent sediment from entering streams and
waterways. In the case of stream restoration work, the sediment is already present in the
system.
• Past studies have shown that the amount of sediment disturbed by in- channel stream
restoration projects conducted at near base flow conditions is equivalent to sediment loads
produced during natural small storm events. Therefore, sediment delivery downstream from
stream restoration projects is comparable to the natural background sediment load for most
streams.
• Pump- around systems dewater sections of stream that support aquatic life, including fish and
macrobenthic aquatic insects. Dewatering sections of stream for significant periods can kill the
aquatic life in that section of stream. For the Fisher River - Hodges Reach Project, this could
impact trout populations within the reach. This can be avoided by working in the wet during in-
channel stream restoration work.
With the concerns above in mind, we propose the following practices be implemented instead of a
pump- around diversion(s) for the Dog Creek and Potato Creek Projects:
• Construction will be limited to periods of near base flow conditions, and the work completed as
expeditiously as possible.
• Contractor should make every effort to keep equipment out of the active stream flow, when
practicable.
• Only one piece of excavating equipment should be allowed to work in the active stream for a
designated stream restoration reach.
• Erosion control measures on the construction site will focus on keeping sediment from the
surrounding land and streambanks from entering the stream channel.