20131177 Ver 1_Response to IRT questions from Credit Release_20170510

Strickland, Bev
From: Byers, Jake <[e-mail]>
Sent: Friday, April 14, 2017 12:40 PM
To: Tugwell, Todd J CIV USARMY CESAW (US); Haupt, Mac; Hughes, Andrea W CIV
USARMY CESAW (US); Baker, Virginia; Browning, Kimberly D CIV USARMY CESAW (US)
Cc: Schaffer, Jeff, Wiesner, Paul; Miguez, Kristin; Tsomides, Harry; King, Scott
Subject: Response to IRT questions from Credit Release
IRT members,
Below are responses to questions or comments brought up by IRT members during the Credit release meeting held on
4/3/17 regarding Michael Baker's projects.
• UT Mill Swamp (UT1b)—Confirm that this coastal plain headwater section was measured using the center line of
the valley.
The attached map shows the centerline of the UT1b valley(in red), centerline of the design alignment, and centerline of
the valley as measured by the as-built survey.
Mitigation Plan As-Built Measurement of Valley(Drawn)
Valley length (feet) 2068 2093 1996
Credits (@1:1) 2068 2093 1996
Credit reduction from as-built vs drawn valley length: 2093-1996= 97 credits.
If the IRT considers the valley length of UT1b as presented in MYO, MY1, MY2, and MY3 that was based on the as-built
survey to be inaccurate,the total stream credits provided by the UT to Mill Swamp project will be reduced from 4,006 to
3,909 credits. (Baker/DMS contract=3,833 credits)
• UT Cane Creek(XS-1)—Discrepancy between cross section geometry numbers presented in MY2 report vs MY3
report on same cross section.
During MY3 report compilation, it was discovered that the data that had been entered into XS-1 during MY2 looked
erroneous as compared to MY3 data. Upon inspection, it was determined that during MY2 reporting, data for XS-11 had
been entered into the MY2 report instead of XS-1. This mistake was corrected in the MY3 report as to accurately reflect
the cross section geometry. However no note was included to describe this.
• Brown Creek Tributaries—discrepancy between assets generated on UT4-R5 from the mitigation plan to the As-
built report.
See below table for assets generated by UT4, R5a-b:
R5a— R5b— R5a—As- R5b-As- R5a—Drawn R5b—Drawn
Mitigation Plan Mitigation Plan Built Built Centerline Centerline
Stream length 386 1535 391 1582 388 1536
(feet)
Ratio 1.5:1 1.5:1 1.5:1 1.5:1 1.5:1 1.5:1
Credits 1 257 1 1024 1 261 1 1055 1 259 1 1024
1

Totals I 1281 I 1316 I 1283
There is a discrepancy of—49'when basing stream length along a drawn stream centerline "eyeballed" between the top
of banks as compared to a surveyed thalweg. However Baker very much disagrees with retroactively re-measuring
stream lengths on existing projects in monitoring years based off of the assumed stream centerline. Surveying the
stream thalweg has always been the industry standard methodology for providing these lengths and determining the
credits generated from a providers point of view. I am unaware of any providers that utilize the proposed methodology
to determine stream lengths during the baseline stage of mitigation projects. I do however concede that does not mean
that no providers do, only that I do not know of any. The point is well taken that the regulatory agencies base their
assessments of impacts on stream centerline and if formal direction and guidance is provided/issued,we will measure
stream lengths based on assumed centerlines moving forward for all new projects. But since I'm unaware of any such
guidance, Baker respectfully request that no reductions in credit or additional action be taken in regards to this matter.
• UT to Town Creek—Additional credit generated from wider buffers
Resolution pending. TBD.
Please let me know if you have any concerns or questions regarding the above. If we need to take any additional action,
please let me know. If no additional request are made,we will consider the above matters resolved.
Thanks,
-Jake
Jacob"Jake" Byers, PE I NC Ecosystem Services Manager I Michael Baker Engineering, Inc., a unit of Michael Baker
International
797 Haywood Road, Suite 2011 Asheville, North Carolina 28806 1 [O] 828-412-6101 1 [M] 919-259-4814
[e-mail] I www.mbakerintl.com
MichaelBaker
INTERNATIONAL
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