20151027 Ver 2_USACE Email_20200722

Moore, Andrew W
From: Fuemmeler, Amanda J CIV (USA) <[e-mail]>
Sent: Wednesday, July 22, 2020 3:35 PM
To: Jake McLean; Moore, Andrew W; Leslie, Andrea J
Subject: RE: [External] RE: Request for Additional Information, Lake Tomahawk Sediment
Management, Buncombe County (DWR Project #20151027 V2)
Attachments: TomahawkDisposal.pdf
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
Thanks Jake. Attached is a pdf. of the location that you said the spoil will be placed. We would condition the permit to
state that no wetlands/streams is authorized to be filled with the spoil so you may just want to double check that they
aren't wanting to fill that ditch/stream immediately to the north of these coordinates. Other than that nothing else on
my end, thanks.
Amanda
828-271-7980 ext. 4225
From: Jake McLean <[e-mail]>
Sent: Wednesday, July 22, 2020 8:36 AM
To: Fuemmeler, Amanda J CIV (USA) <[e-mail]>; Moore, Andrew W
<[e-mail]>; Leslie, Andrea J <[e-mail]>
Subject: [Non-DoD Source] Re: [External] RE: Request for Additional Information, Lake Tomahawk Sediment
Management, Buncombe County (DWR Project #20151027 V2)
Here's the response to Andrew's comments below. The 2nd item below from Andrew's comments was also
the remaining item from Andrea's original email that I did not respond to. Her email asked about: (1)
dewatering (see below), (2) seed mix (response: seed mix will be to replace what is there currently won't
necessarily be native), and (3) verification of the dredging limits (response: channel only, not lake).
For the spoil site:
The address is 681 North Fork Road, Black Mountain, N.C. 28711 -82* 21' 22.23" / 35* 38' 17.85
For the lake inspection, the following has been added to plans:
The Town draws down the lake for inspection purposes every year and occasionally in advance of expected large storms
for flood management (to prevent flooding of the rec center building). The valve is near the bottom of the Lake but not
at the lowest point, the valve is operated at a gate valve beside the spillway. Town staff have indicated that a minor
increase in turbidity from opening the valve dissipates very quickly - within a matter of couple minutes or
less. Thereafter the discharge runs clean. For the purposes of this project, Town staff will monitor the discharge when
the valve is opened and for a period of 15 minutes. A short period of minor turbidity is anticipated as the intake area
normalizes to the release (anticipated to be a couple of minutes as this is normal). If the turbidity does not dissipate
after a period of 10 minutes, or if the turbidity becomes visibly worse during this period, the Town will close the valve
and evaluate what can be done to address the cause of abnormal turbidity and proceed in a matter that does not violate
state turbidity standards. Based on prior drawdown efforts, it is anticipated that once clear, the discharge will remain
so. The discharge will be visually monitored daily during the drawdown to verify a turbidity free discharge. The lake is on
average 7-8' deep and the drawdown period takes approximately 2-3 days.

Finally, Andrew asked for some additional details pertaining to the proposed retaining wall. I have updated the plans to
show that a precast concrete block or boulder wall will be constructed to a height of 4-6' and buttressed with clean
riprap at the toe. The location of the wall has been added to plansheet 1.01 and the section view on sheet 1.02
refined. These two sheets are attached.
Let me know if there's anything else any of you have questions or comments about.
Thanks,
Jake
From: Fuemmeler, Amanda J CIV (USA) <[e-mail]>
Sent: Monday, July 20, 2020 5:04 PM
To: Moore, Andrew W <[e-mail]>; Jake McLean <[e-mail]>; Leslie, Andrea J
<[e-mail]>
Subject: RE: [External] RE: Request for Additional Information, Lake Tomahawk Sediment Management, Buncombe
County (DWR Project #20151027 V2)
Hi Jake,
Just checking in on this one and will need the same information as Andrew in regards to the location of the disposal site
to make sure there is no issue with dumping spoil/dredge in wetlands/other waters. If you think it might be a while
before you can provide this information, let me know as I will need to temporarily withdraw the application in our
system. I will also need Andrea's comment letter as well which seems like she had questions before issuing from a
previous email chain..
Amanda
828-271-7980 ext. 4225
From: Moore, Andrew W <[e-mail]>
Sent: Monday, June 22, 2020 4:24 PM
To: Jake McLean <[e-mail]>; Leslie, Andrea J <[e-mail]>
Cc: Fuemmeler, Amanda J CIV (US) <[e-mail]>
Subject: [Non-DoD Source] RE: [External] RE: Request for Additional Information, Lake Tomahawk Sediment
Management, Buncombe County (DWR Project #20151027 V2)
Jake,
Thank you for the information. Under some circumstances, dewatering of dredge spoils can cause turbidity issues if
allowed to re-enter jurisdictional waters. Therefore, the preference is to load directly to truck and haul to the dump site,
assuming there are no jurisdictional waters that may be impacted there or en route.
The Division will consider the response below incomplete until the additional details regarding the wall, referenced in
your email, are provided. In addition please provide the following:
1. The address or latitude/longitude for the dredge spoil dump site; and
2. A narrative describing how the Town, or site contractors, will monitor Tomahawk Branch during lake drawdown
to ensure no violations of North Carolina surface water standards (e.g. turbidity, in -stream sediment) occur
during drawdown and response actions if sediment loss is observed.
Feel free to contact me if you have any questions or would like to discuss further.

Andrew W. Moore, PG
Environmental Specialist — Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ — Division of Water Resources
828 296 4684 office
email: [e-mail]
2090 U.S. Hwy. 70
Swannanoa, N.C. 28778
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Jake McLean[mailto:[e-mail]]
Sent: Friday, June 19, 2020 1:47 PM
To: Leslie, Andrea J <[e-mail]>; Moore, Andrew W <[e-mail]>
Cc: Fuemmeler, Amanda J CIV (US) <[e-mail]>
Subject: [External] RE: Request for Additional Information, Lake Tomahawk Sediment Management, Buncombe County
(DWR Project #20151027 V2)
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
This is from the Town highlighted below. Is dewatering required, or if the town has and is able to haul without
issue is that OK? This is pretty sandy/gravelly stuff so I'm thinking it dewaters pretty fast and they probably let
it drip off some before heading down the road. As far as the question Andrew posed about the "wall". There
is an existing boulder wall along the length of the proposed dredging area that is 1-2 courses deep. We are
exploring with the geotech and contractor and Town what the final wall and/or riprap configuration needs to
be to allow them to dredge while ensuring the safety of the operators and equipment sitting on top of the
bank that the wall is holding up and armoring. This may range from adding to and/or armoring what is there to
pulling out what is there and replacing with something new. Let me know if you have any follow-up questions,
and I will be providing some finalized plans that show a few more details once we finalize these. We've
completed geotech and structural analysis and the bridge repair will be fairly simple compared to what we
thought it may be — turns out there are piers supporting the bridge and that those just need to be protected
from future scour. We plan to draw down the lake and pump around the stream flow during this work to
protect the piers. Like I said, I'll send more details as we finalize and will be happy to incorporate any follow-
up comments regarding these.
Jake,
The lake has to be lowered not to exceed one foot per every 24 hours. We do not see sediment when lowering the lake
unless it is after a significant rain event, or the initial opening of the valve. The sediment that we have taken out of the
lake is put straight into the truck and hauled to our dump site a couple miles away and used for beneficial fill.

5Fa"fA-- V !V . 7*,MttA,--W&
Public Works Director
Town of Black Mountain, Public Works
304 Black Mountain Ave.
Black Mountain, N.C. 28711
Office: 828-664-5052
Fax: [phone]
"Keep your head and your heart going in the right direction and you will never have to worry about your feet"
From: Jake McLean <[e-mail]>
Sent: Thursday, June 18, 2020 11:47 AM
To: Leslie, Andrea J <[e-mail]>; Moore, Andrew W <[e-mail]>
Cc: Fuemmeler, Amanda J CIV (US) <[e-mail]>
Subject: Re: Request for Additional Information, Lake Tomahawk Sediment Management, Buncombe County (DWR
Project #20151027 V2)
10-4. Chasing down #1 with the Town.
Sorry for the mixed information- I guess we just haven't nailed this down. It is maintained grass now, and I
think that the intent will be to seed back something they can continue to mow and consistent with what is
there.
That's right, just the channel.
From: Leslie, Andrea J <[e-mail]>
Sent: Thursday, June 18, 2020 11:32 AM
To: Moore, Andrew W <[e-mail]>; Jake McLean <[e-mail]>
Cc: Fuemmeler, Amanda J CIV (US) <[e-mail]>
Subject: RE: Request for Additional Information, Lake Tomahawk Sediment Management, Buncombe County (DWR
Project #20151027 V2)
Howdy,
Am reviewing this application now, and I've got a couple of questions, too:
1. I echo Andrew's 1st question - we just need to understand how you will be dewater that
area. If via bottom valve, is that regularly used and in working order? As you may know, the

Swannanoa River downstream supports hellbenders and rainbow trout, and we need to make
sure there is little risk of sediment inputs from the project.
2. You mention using native riparian seeding in some areas but your seed list includes clover,
orchardgrass (invasive), and big bluestem. Is there another list, and where would you use the
natives vs. the non -natives?
3. You will only be dredging the channel, not the 0.04 acre of lake itself, correct?
Thank you,
Andrea
Andrea Leslie
Mountain Habitat Conservation Coordinator
NC Wildlife Resources Commission
645 Fish Hatchery Rd., Building B
Marion, NC 28752
828-803-6054 (office)
828-400-4223 (cell)
BlockedBlockedwww.ncwildlife. ors
RIaLus.goo le.coml0 [facebook.coml� [twitter.coml E] [youtube.com]
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From: Moore, Andrew W <[e-mail]>
Sent: Tuesday, June 16, 2020 1:30 PM
To: Jake McLean <[e-mail]>
Cc: Fuemmeler, Amanda J CIV (US) <[e-mail]>; Leslie, Andrea J <[e-mail]>
Subject: Request for Additional Information, Lake Tomahawk Sediment Management, Buncombe County (DWR Project
#20151027 V2)
Jake,
On May 22, 2020, the Division received your application requesting a 401 Water Quality Certification for the subject
project. The Division has determined that your application is incomplete and cannot be processed. The application is on
hold until all of the following information is received:
1. How will the existing pond be de -watered? If through a bottom drain valve, how will you ensure no more than a
de minimis amount of sediment is released to the receiving stream? [15A NCAC 02B .0200]
2. Will dredge spoils be dewatered prior to off -site transport? If so, how? [15A NCAC 02H .0506(b)(2)]
3. Where will dredge spoils be disposed? [15A NCAC 02H .0506 (b)(2) and (c)(2)]

4. It appears from Sheet 1.02 that a boulder wall or rip rap will be installed along the streambanks? Please clarify
where this impact is proposed and why it is necessary? [15A NCAC 02H .0502]
Pursuant to Title 15A NCAC 02H .0502(c), the applicant shall furnish all of the above requested information for the
proper consideration of the application. If all of the requested information is not received, the Division will be unable to
approve the application and it will be denied as incomplete.
Feel free to contact me if you have any questions.
Andrew W. Moore, PG
Environmental Specialist — Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ — Division of Water Resources
828 296 4684 office
email: Andrew.W.Moore(a)ncdenr.gov
2090 U.S. Hwy. 70
Swannanoa, N.C. 28778
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.