20130428 Ver 2_More Info Received - Email_20170321

Homewood, Sue
From:Randy Forsythe <[e-mail]>
Sent:Tuesday, March 21, 2017 6:40 PM
To:Bailey, David E CIV USARMY CESAW (US)
Cc:Homewood, Sue
Subject:Re: \[EXTERNAL\] NW39 PCN submission and NW27 extension request for ancillary road
crossing at the Church St & Univ Drive NW27 project site
Thanks for the quick review. In response:

1. No, I've design the stream to include riffle cobble armour sized above mobilization (=> 10") thresholds so riprap for
energy dissipation is not required above or below the proposed crossing. This rip rap practice strikes me as
unnecessary when culverts are properly bedded below the stream armour and where the stream has been restored to
maintain consistent sediment transport dynamics and bed shear stresses. The riffle material is not yet in place, and
these final components of the restoration (habitat features) I typically install under 'beta' flow conditions so I can get
the hydraulics for all the pool and riffle grades to fit the design goals. E.g. I build each riffle crest from
downstream to upstream so I can carefully back water each pool to the beginning of the next upstream riffle. It's much
easier to do that with flow than not. Thus this habitat structural phase of work is being postponed to after the potential
crossing is established to eliminate temporary impacts and get these habitat aspects fully functional as we work
progressively up and into the each of the two proposed culverts \[which when the stream restoration is completed will
have riffle armour a minimum of 8" tp 1' of depth through each culvert\]. Kevan Andrews \[my PE for the crossings\]
was informed of these requirements when he prepared the culvert plans submitted with the PCN. The requirement that
each culvert be 'buried' below stream grade is a somewhat problematic criteria when the stream in question has not yet
had its riffles completed. I have the stream cobble armour stockpiled onsite for all the riffle zones for placement once
we resolve this crossing should anyone wish to compare these natural stream cobble materials to rip-rap.

2. No temporary impacts are required, This is in part due to the fact that the restoration work is not yet complete and
check dams may still be needed to finalize habitat features and fix 3-4 areas that have not meet QA/QC restoration
goals prior to submitting our notice of completion and as-built documents. Two of the problematic areas not meeting
QA/QC is a zone of channel aggradation just below the proposed new culvert, and an area of bank instability just
above the proposed crossing. I plan on getting these two issues fixed during culvert installation if the NW39 is
approved. Check dams for sediment and erosion control will be in place at the lower end when we do our final habitat
and QA/QC phase of restoration work, so this is NOT in our view an impact arising from the NW39 effort.

Regarding flow in the restored stream: The old diversion ditch dug in 1941 \[under a permit from the NC Health
department\] has been filled. The two prior pond areas have now been mostly filled. I have two very small residual
areas at each end to fill and close up. The lower is the plug needing to be installed to prevent underground piping and
sink hole formation where the old channel meets the new stream. I have large 2-4' diameter rocks to be wrapped in
non-woven fabric going into this plug hopefully tomorrow. The 72" culvert is however still in place at the upper end
and only partially blocked from storm flow. Thus at this time full flow is NOT established in the new stream corridor.
My estimate is we have control in the new corridor for only the OHWM flow, but not above that stage (~18"-24"; as it
might over time be defined by the new hydraulic conditions). Once we pour the concrete plug at the upstream invert on
this 72" pipe all flow will thenceforth be through the new reach. That concrete plug is not likely to be poured until a
legal understanding with the Pediatric practice regarding long term easements are resolved, as they own this end of
the pipe and are concerned about long term stability; but have 2 years to go on a restrictive convenant with neighbors
over trees that were planted over the pipe. That restrictive convenant does not expire till July of 2019, unfortunately, so
we are working hard to find a creative work around to get this resolved. That is targeted for resolution by the end of
this July. Currently storm stages over the OHWM will get into this pipe and then be dispersed as sheet flow into our
new wetlands below the pipe.

1

I've no problems meeting you or Sue onsite if you need some feel for current conditions.

Randy Forsythe

On 3/21/17 4:43 PM, Bailey, David E CIV USARMY CESAW (US) wrote:
Hi Randy. A few quick confirmation questions related to the above referenced
project:

1) Will any rip rap be proposed up or downstream of the proposed crossing ? If so,
please add to the plan/profile as well as a separate line item in the PCN.
2) Will any temporary impacts be required outside of the permanent proposed impact
footprint for dewatering/construction access? If so, please add to the plan sheet
as well as a separate line item in the PCN.

Also, has full flow been released into the new stream channel, or is it still held
within the old channelized stream?

Lastly, related to your concern regarding expiration of the NWP 27 permit and
request for reauthorization: as long as the work authorized under the NWP 27 is
complete by March 18, 2018, the NWP 27 portion of this project will not need to be
re-authorized under the new Nationwide Permits.

Review of your project will continue in the coming days, including coordination
with Sue. If you have any questions in the meantime feel free to give me a call.

-Dave Bailey

---
David E. Bailey, PWS
Regulatory Project Manager
US Army Corps of Engineers
CE-SAW-RG-R
3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
Phone: [phone], Ext. 30.
Fax: [phone]
Email: [e-mail]

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-----Original Message-----
From: Randy Forsythe \[mailto:[e-mail]\]
Sent: Monday, March 13, 2017 10:16 AM
To: Bailey, David E CIV USARMY CESAW (US) <[e-mail]>
Cc: Homewood, Sue <[e-mail]>
Subject: Re: \[EXTERNAL\] NW39 PCN submission and NW27 extension request for
ancillary road crossing at the Church St & Univ Drive NW27 project site

Thank you David for the update.

Attached for your records is a PDF with: 1) a signed page 10 (as DWQ noted we had
not signed that page), and 2) a copy of the 'authorization' form DWQ prefers
applicants use for an agent to represent the owner.

Randy Forsythe

On 3/9/17 9:36 AM, Bailey, David E CIV USARMY CESAW (US) wrote:
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