20140774 Ver 1_More Info Received_20140825

Price, Zan (George)
From: Jake McLean <jmclean @wildlandseng.com>
Sent: Monday, August 25, 2014 1:42 PM
To: Fox, Tim
Cc: Aaron Earley; Cranford, Chuck
Subject: RE: Townsend /Peek Stream Enhancement
Attachments: Stone_ Sizing _WSI_Peek_Ellis_Townsend.pdf; WSI Townsend Detail Corrections.pdf; WSI
Peek Detail Corrections.pdf; WSI Ellis_60pctbid_8- 25- 14_Details.pdf
Tim,
I am responding for Wildlands to your email below sent to Aaron regarding our permits. We have three projects
submitted at present for permitting under the NCWSI (Western Stream Initiative) program, the two you refer to below,
and another in McDowell County called "Ellis" recently sent in.
We are accustomed to providing the requested data for most projects, however we feel that some of this is not
applicable for these three projects. Where applicable, I am providing the information (attached). Please refer to my
explanations below- bullets are the requested information:
• Reference Reach data.
None of the 3 sites presently in for permitting are being realigned- there is no new pattern and minimal or no
modification to existing profiles.
At Peek we are building benching at the elevation of other existing benching on the site. We are also abandoning a
severe oxbow (where the stream has already created a second straighter cut -off channel). Bankfull dimensions are
taken from existing features on the Peek site, both within and immediately downstream of the project site. Various
measurements were taken with (1) survey data, (2) aerial photography review, and (3) tape in field. These have not
been documented in an analysis document but have been used as checks against our design dimensions.
At Townsend and Ellis, there is no realignment and minimal dimension modification — the focus of these two projects is
bank sloping. Structures are being used where deemed appropriate to reduce risk of bank failures. Based on this, we
have not performed formal reference reach data analysis outside of the project area. Ellis is incised but we are not
addressing this as it is impossible to do so within the constraints of the project. Bankfull features were analyzed from
the existing conditions data but have little bearing on the design as only bank sloping is possible. Townsend is well
connected to its floodplain and we visited multiple other locations on the river, and also used aerial photography to
validate dimensions, as well as to analyze and validate how structures have been used in the past to varying degrees of
success and to analyze success factors (angles, tie -ins, stone characteristics).
• Sizing of material (structures /riffles).
For all 3 sites, empirical stone sizing data has been used to fine tune standard details. We have found professional
judgment is a reasonable method for sizing structure stone, however modeling has been used for validation and is
described and presented. HEC -RAS models used for FEMA study of the 100 -year event have been re -used to model
smaller flow events at and around the bankfull flow. HEC -RAS provides channel shear stress in Ib /ft ^2. For the purpose
of stone sizing, bankfull flow rate used in the model was set based on empirical regional curve equations. Larger and
smaller flows were modeled to assess shear stress variability at different flow rates. Shear stress from the model was
used with the attached charts to size riffle and structure stone.
At Peek, riffle stone has been sized to include a range of particles in the 1 -6" range based off of Shield
relations. Structure stone was sized based on professional judgment and checked against the Rosgen rock sizing chart
for vane structures. The required minimum rock size based on that chart is 2.6 ft. We have given the contractor
recommendations to use 4x2.5x2 or 3x3x2, either of which would have a similar weight to a 2.6 ft cube.
1

At Townsend, riffle stone will be reused from existing riffles and channel material. This material is in line with Shield
curve data which suggests 3 -10" stone would be mobile at bankfull. Structure stone was sized based on review of
multiple prior vane installations in the corridor and assessment of stability and was set as 4x3x2 (minimum). In both
cases, the design checks (Shields relation & Rosgen rock sizing) are satisfied.
At Ellis site, stone sizing is very comparable to Peek site. There is only one riffle on the project. It is sized with both the
chart in mind, and based on an existing constructed riffle below a ford crossing that is stable at a somewhat steeper than
typical slope. Average stone size in that riffle is 6 ". Structure stone at Ellis is sized based on Rosgen rock sizing; the
contractor has been given a materials list that specifies recommendations to use 4x2.5x2 or 3x3x2 (minimum), either of
which would have a similar weight to a 2.6 ft cube.
• The detail of the cross vanes provided does not include values, such as, % slope, angle, etc.
Attached are revised detail sheets for each site (for Ellis I have attached the entire planset). For most sites it was our
intent to add this information to the final plans. In addition, this program is a more collaborative effort than a typical
stream project. Contractors are pre - qualified and assigned to projects rather than having to competitively bid for
them. Contractors and engineers work together in the field and the engineer and /or designer is on site multiple days
per week helping interpret the plans. As such, some of these items will be more field- engineered than occurs as part of
a typical stream project- notes on plans such as "as directed by engineer" reflect this. In addition, vane tie -in locations
and other structures will be field adjusted as deemed appropriate by the engineer or designer.
Let me know if you have any concerns or additional requests. Please also understand that many of the NRCS projects
require more of a stabilization- oriented approach than your typical stream restoration project. We are doing our best tc
design holistic solutions where conditions allow, but it varies from site to site. None - the -less, in all cases, the program is
implementing effective measures like streambank sloping, native plantings, buffers where possible, fencing out cattle
(not shown on plans but happening apart from our stream efforts), and addressing chronic erosion problem areas. This
program is effective because it is flexible; it allows for the implementation of positive efforts in settings where other
grant or stream repair funding is typically not applicable /available or carries restrictions on landowners that prove
unacceptable.
Thanks for your review,
Jake
Jake McLean I Water Resource Engineer, Asheville Team Leader
0:828.633.6401 M: 828.545.3865
Wildlands Engineering, Inc.
15 Possum Trot, Suite 1
Asheville, NC 28806
From: Aaron Earley
Sent: Friday, August 22, 2014 8:19 AM
To: Jake McLean
Subject: FW: Townsend /Peek Stream Enhancement
Aaron Earley, PE, CFM I Senior Water Resources Engineer
0: 704.332.7754 x109 M: 704.819.0848
Wildlands Engineering, Inc.
1430 S. Mint St, Suite 104

Charlotte, NC 28203
From: Fox, Tim [mailto:tim.fox @ncdenr.gov]
Sent: Friday, August 22, 2014 8:17 AM
To: Aaron Earley
Cc: Cranford, Chuck
Subject: Townsend /Peek Stream Enhancement
Aaron,
Hope you are well.
I was reviewing these projects and was wondering if you could provide the following information.
• Reference Reach data.
• Sizing of material (structures /riffles).
• The detail of the cross vanes provided does not include values, such as, % slope, angle, etc.
We generally require this information for most 401 projects. If you recently submitted any other projects with similar
features could you provide this information for them as well.
If I am missing something let me know. I'm in the field today but should be in the office on Monday if you would like to
discuss further.
Have a great weekend.
Tim
Tim Fox - tim.fox @ncdenr.gov
North Carolina Dept. of Environment and Natural Resources
Asheville Regional Office
Division of Water Resources — Water Quality Programs
2090 U.S. 70 Highway
Swannanoa, NC 28778
Tel: 828 - 296 -4500
Fax: 828 - 299 -7043
Notice: Email correspondence to and from this address may be subject to the NC Public Records Law and may be
disclosed to third parties.
3