20030147 Ver 2_Project Notification_20190709

WATER STRATEGY, HYDRO
LICENSING AND LAKE SERVICES

Duke Energy
526 South Church Street/EC12Y
Charlotte, NC 28202

July 9, 2019

The Honorable Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street N.E.
Washington, DC 20426

Re: Duke Energy Progress, LLC
Yadkin-Pee Dee Hydroelectric Project No. 2206
License Article 401(c) Notification

Dear Secretary Bose:

Duke Energy Progress, LLC (Duke Energy), licensee for the Yadkin-Pee Dee Hydro Project (Project No.
2206), is required by License Article 401(c) to notify the Federal Energy Regulatory Commission (FERC
or Commission) of planned or unplanned deviations from the requirements of the New License issued by
the Commission on April 1, 2015. Duke Energy hereby notifies the Commission of a planned deviation
from the minimum flow requirement for the Blewett Falls Development beginning on July 15, 2019 and
lasting for approximately six weeks.

Background
On October 5, 2018, the Commission was notified of the flood conditions experienced by the Yadkin-Pee
Dee River Basin due to heavy rainfall from Hurricane Florence. This resulted in a flooded powerhouse at
the Blewett Falls Development which caused all six generating units to become inoperable. FERC
acknowledged the notification on October 29, 20181.

On February 6 and March 1, 2019, Duke Energy notified the Commission of compliance requirements of
the New License that will be impacted by the inoperable generating units. FERC acknowledged this
notification on March 20, 2019 2.

Minimum flow Deviation Request
Restoration of the generating units is underway at the Blewett Falls Development. Duke Energy has
developed a plan to seal the cracks in the powerhouse which requires access to the powerhouse through the
tailrace tunnels. The contractor will need to use a barge to provide a larger work platform while under the
powerhouse but this will require a lower water level in the tailrace. The current minimum flow requirement
at Blewett Falls is 1,200 cfs. A lower minimum flow over the spillway will allow the contractor more
consistent access to the tailrace tunnel which will facilitate completion of the work more quickly. This
work will require four to six weeks to complete, assuming dry weather conditions continue.

1 FERC E-Library Accession No. 20181029-3000
2 FERC E-Library Accession No. 20190320-3081
July 9 , 2019
Kimberly D. Bose, Secretary
Page 2

Additionally, while the flow over the spillway is low, Duke Energy will perform the Gravel Recruitment
Study required by the 401 Water Quality Certification (Appendix A of the New License). This study is
required to be completed within five years of receiving the New License.

The minimum flow at Blewett Falls will likely be between 700 cfs and 1,000 cfs during this flow deviation
period. Duke Energy will modify operations at the upstream Tillery Development which will result in the
lower minimum flow at Blewett Falls during the daylight hours. However, there will also be a period of
time each day when the minimum flow is at or above 1,200 cfs at Blewett Falls. This will occur when flow
from generation at the Tillery Development arrives at the Blewett Falls Dam.

As required by Article 401(c), Duke Energy consulted with the North Carolina Department of
Environmental Quality, Division of Water Resources (DWR), North Carolina Wildlife Resources
Commission (WRC), US fish and Wildlife Service (FWS), National Marine Fisheries Service (NMFS), and
South Carolina Department of Natural Resources (DNR) regarding the extent and duration of the minimum
flow deviation request (see Enclosure). During this consultation, Duke Energy agreed to the following:
• Adjust the generation schedule at the Tillery Development to provide a lower flow over the spillway
at Blewett Falls during the daylight hours. Duke Energy will provide additional information to the
resource agencies on what the expected minimum flow will be at the Blewett Falls Development.
• On a weekly basis, Duke Energy will observe conditions in the Blewett Falls tailrace for signs of
stressed or dead fish. If the flow in the tailrace falls below 700 cfs, Duke Energy will provide the
observations daily.
• Provide weekly updates to the resource agencies on the status of the flow releases and water quality
by sending data from the USGS gages in the Tillery Development Tailrace (Gage No.
0212378405), in the Blewett Falls Tailrace (Gage No. 0212880025), at Highway 74 (Gage No.
02129000) and at Jones Creek Shoal (Gage No. 02129375).
Duke Energy respectfully requests expeditious review of this proposal to allow completion of the work
while dry conditions exist in the Yadkin-Pee Dee River Basin. If you have questions or require clarification,
please contact Tami Styer at [phone] ([e-mail]).

Sincerely,
Jeffrey G. Lineberger, P.E.
Director, Water Strategy and Hydro Licensing
Duke Energy

Enclosure

July 9 , 2019
Kimberly D. Bose, Secretary
Page 3

cc: Chris Goudreau – NC Wildlife Resources Commission
Lawrence Dorsey - NC Wildlife Resources Commission
John Ellis – US Fish and Wildlife Service
Fritz Rohde – National Marine Fisheries Service
Andy Herndon - National Marine Fisheries Service
Elizabeth Miller – SC Department of Natural Resources
Bill Post - SC Department of Natural Resources
Fred Tarver – NC Department of Environmental Quality
Chonticha McDaniel – NC Division of Water Resources
Tami Styer
David Scott
Lynne Dunn
From:Tarver, Fred
To:Styer, Tami
Cc:Mcdaniel, Chonticha
Subject:RE: [External] Blewett Falls Temporary Minimum Flow Modification Request
Date:Monday, July 8, 2019 11:53:25 AM
Attachments:image007.png
image008.png
Tami,
Yes, given the hurricane-related damage to the Blewett Falls unit and the need to proceed with repairs, the process
discussed on conference call on Wednesday seems reasonable. Hopefully, we won’t see any deviations below NC water
quality standards.
Thanks,
Fred

Fred R Tarver III
Environmental Flows Program Consultant
Water Planning Section - Basin Plannning Branch
Department of Environmental Quality

919-707-9029 office
[e-mail]

Division of Water Resources
1611 Mail Service Center
Raleigh NC 27699-1611

Email correspondence to & from this address is subject to the N.C. Public Records Law & may be disclosed to third parties!

From: Styer, Tami <[e-mail]>
Sent: Friday, July 05, 2019 3:54 PM
To: Tarver, Fred <[e-mail]>
Subject: FW: [External] Blewett Falls Temporary Minimum Flow Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

H Fred,
Do you agree with our approach or is there additional information I can provide.
Thanks!
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Fritz Rohde - NOAA Federal [mailto:[e-mail]]
Sent: Friday, July 5, 2019 10:11 AM
To: Goudreau, Chris J. <[e-mail]>
Cc: Styer, Tami <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; Twyla Cheatwood
<[e-mail]>; Andrew Herndon <[e-mail]>; John Ellis <[e-mail]>;
Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: Re: [External] Blewett Falls Temporary Minimum Flow Modification Request

Tami:

NMFS agrees that your approach is reasonable and agrees to your proposal.

Fritz

On Wed, Jul 3, 2019 at 4:32 PM Goudreau, Chris J. <[e-mail]> wrote:
Tami,

The NC Wildlife Resources Commission agrees with the approach outlined below. Thanks for putting together the
conference call.

Chris

--------------------------------------------------------------------
Chris Goudreau
Hydropower & Special Projects Coordinator
Habitat Conservation Division

NC Wildlife Resources Commission
645 Fish Hatchery Road
Marion, NC 28752
office: 828-803-6045
mobile: [phone]
[e-mail]

ncwildlife.org

From: Styer, Tami <[e-mail]>
Sent: Wednesday, July 03, 2019 3:28 PM
To: Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: [WARNING: UNSCANNABLE EXTRACTION FAILED]RE: [External] Blewett Falls Temporary Minimum Flow
Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

Thank you for calling in on our conference call today to discuss the Blewett Falls minimum flow deviation request. To
help explain our plan, I provided the graph below to show the relationship between the generation at Tillery, the
Blewett Falls lake level and the flow at the Hwy 74 Bridge below Blewett Falls.

As we discussed, the minimum flow from Tillery during the evening hours is typically around 800 cfs. The minimum
flow can be as low as 500 to 600 cfs during the day. These minimum releases should result in a minimum flow at
Blewett Falls of 700 to 1000 cfs (taking into account evaporation, leakage and inflow from Rocky River). Below is a
summary of the action items from our call today.

To accommodate the work under the powerhouse and the Gravel Recruitment Study, Duke Energy will do the
following:
Adjust the generation schedule at Tillery to provide a lower flow over the spillway at Blewett Falls during the
daylight hours. As soon as we determine this generation schedule, we’ll send the agencies an update on what
we expect the Blewett Falls minimum flow to be.
On a weekly basis, we’ll provide monitoring of the Blewett Falls tailrace for signs of stressed or dead fish. If the
flow in the tailrace falls below 700 cfs, we’ll provide this monitoring daily.
Provide weekly updates to the agencies on the status of the flow releases and water quality by sending data
from the USGS gage in the Tillery tailrace (0212378405), in the Blewett Falls tailrace (0212880025), Highway
74 gage (02129000) and the gage at Jones Creek Shoal (02129375).

I plan to send FERC a request for approval of the minimum flow deviation to start the week of 7/15. I’m not sure if
we can get approval that quickly but we’ll plan to start with the testing as soon as we receive approval. Please
provide an email and let me know if you support our plan. I will include this in the request to FERC as the required
consultation.

Thanks again for your cooperation and quick response to our request.

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Styer, Tami
Sent: Tuesday, July 2, 2019 2:25 PM
To: Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

Thanks Chris. That’s a very good point. I obviously forgot about Tillery’s min flow requirement when I said the
lowest flow going over the spillway at Blewett Falls would be 300 cfs. That assumes just leakage through Blewett
Falls and inflow from Rocky River. With Tillery’s minimum flow, which is usually around 400 cfs, the min flow over
the Blewett Falls spillway should be between 600 and 700 cfs. I can see why you would be concerned that there
would be no flow out of Tillery but that is not the case. We are not planning to modify Tillery’s minimum flow
requirement, only the time of day we generate.

We can discuss this in more detail tomorrow.
Thanks again!
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Goudreau, Chris J. [mailto:[e-mail]]
Sent: Tuesday, July 2, 2019 12:34 PM
To: Styer, Tami <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

I can do a call anytime tomorrow and probably Friday.

My concern is not only the Blewett tailwater, but also the Tillery reach. I’m wondering if Tillery might run the min
flow for longer hours than normal; that would also boost temps in that reach, depending on the time of day. I’d like
to hear first-hand how both developments will be operated.

And thanks for the reminder about the WQ gage below Blewett.

From: Styer, Tami <[e-mail]>
Sent: Tuesday, July 02, 2019 12:16 PM
To: Elizabeth Miller <[e-mail]>; Goudreau, Chris J. <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

Thanks everyone for your quick review of the note. I would be glad to set up a conference call to discuss. Let me
offer the following additional info and if you still would like to discuss, would you be available this afternoon? Let’s
say 3pm? I’m also available tomorrow all day except 10-11am and all day Friday.

Additional Information
Under normal operations at Blewett Falls, we provide the minimum flow with generation and utilize vent valves to
provide additional aeration, when needed to meet the water quality standard. Given that we have no operational
units at Blewett Falls, we have no way to enhance or manage the water quality. It will be whatever the natural
conditions are with the water going over the spillway. Please recall the notification we sent to FERC on Feb 6, 2019
(attached), and their response on Mar 20 (also attached).

There has been one instance so far this year where the DO value was below the minimum standard of 4.0 mg/l (see
below). Chris, this gage is in the tailrace (0212880025). What we’ve seen so far this year is that the DO values
recorded during the day are higher and they decline at night. By providing the higher min flow in the late afternoon
early evening, which is when the generation flow from Tillery should arrive at Blewett Falls, we hope it will provide
additional flow to help the DO levels in the river stay above the standard. The lower minimum flow during the day
may result in lower DO values but without the generating units, the only potential to enhance the DO would be to
increase the flow over the spillway, but this would prevent the use of the barge to seal the cracks in the
powerhouse.

We believe this is the best opportunity to do both the Gravel Recruitment Study and seal the cracks in the
powerhouse even though it is a hotter time of the year. We need to get this work completed to complete
restoration of the powerhouse. If we wait until the fall when the DO values are typically higher, that usually
coincides with higher inflow which would make it very difficult with limited access under the powerhouse.

Providing the lower flow now will allow us to get the work completed faster and we’ll be taking advantage of what is
already a not-so-great situation because without the generating units operational, the DO is limited to whatever the
natural conditions are in the river.

I hope this helps. If you would still like to have a call, please let me know what time works best and I’ll send out a
meeting notice.
Thanks again for your quick response!
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Elizabeth Miller [mailto:[e-mail]]
Sent: Tuesday, July 2, 2019 11:15 AM
To: Goudreau, Chris J. <[e-mail]>; Tarver, Fred <[e-mail]>; Styer, Tami
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

*** Exercise caution. This is an EXTERNAL email. DO NOT open
attachments or click links from unknown senders or unexpected
email. ***
Tami,
I have some concerns regarding the seasonal timing of the low flow period as well. I would also appreciate further
discussions to understand the potential impacts and evaluate means to minimize the impacts to the system. I can be
available for a conference call this week if that works for others.
Thanks,

Elizabeth C. Miller
SCDNR
Office: [phone]

From: Goudreau, Chris J. <[e-mail]>
Sent: Tuesday, July 2, 2019 11:06 AM
To: Tarver, Fred <[e-mail]>; Styer, Tami <[e-mail]>; Mcdaniel, Chonticha
<[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde <[e-mail]>;
Twyla Cheatwood <[e-mail]>; Andrew Herndon <[e-mail]>; John Ellis
<[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

I am wondering the same thing. This is the hottest time of year, so holding flows are very low levels during the
middle of the day will result in very high temps. Also, I’m guessing that Blewett can’t do anything to boost dissolved
oxygen, so there may be issues with that.

I just downloaded data from USGS gage below Tillery – means for last 30 days and instantaneous (15-min) for past 4
days. Unfortunately, the gage below Blewett doesn’t record WQ data, but I suspect a similar situation.

I’d like to discuss this in more detail. Can we set up a conference call?

From: Tarver, Fred
Sent: Tuesday, July 02, 2019 10:01 AM
To: Styer, Tami <[e-mail]>; Mcdaniel, Chonticha <[e-mail]>;
Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

Tami,
What is Duke’s level of confidence that it can meet WQ standards during this period?
Fred

Fred R Tarver III
Environmental Flows Program Consultant
Water Planning Section - Basin Plannning Branch
Department of Environmental Quality

919-707-9029 office
[e-mail]

Division of Water Resources
1611 Mail Service Center
Raleigh NC 27699-1611

Email correspondence to & from this address is subject to the N.C. Public Records Law & may be disclosed to third
parties!

From: Styer, Tami <[e-mail]>
Sent: Tuesday, July 02, 2019 9:04 AM
To: Tarver, Fred <[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; Goudreau,
Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: [External] Blewett Falls Temporary Minimum Flow Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

Hello Everyone,
As you know, we are in the process of restoring the generating units at Blewett Falls that were flooded last fall during
Hurricane Florence. I’m sending this note as consultation on the need to provide a lower than normal minimum flow
at Blewett Falls for 4 to 6 weeks this summer. Our current minimum flow requirement is 1,200 cfs. Below is an
explanation of the tasks that need to be accomplished during this lower flow period.

1. In the 401 Water Quality Certification, we are required to complete a Gravel Recruitment Study within 5 years
of receiving the new license. The study consists of mapping the substrate in the tailrace down to Highway 74
Bridge. This study is required to duplicate a study done during relicensing, when leakage flow was being
released as the minimum flow from Blewett Falls. Without the generating units operational, we cannot get
the lake below the crest of the dam so we cannot duplicate leakage flow only, but we think we can complete
the study with minimal flow over the spillway.

2. Restoration of the units is continuing and one task to be completed is sealing the cracks in the powerhouse.
This will be done using a barge with access to the powerhouse through the tailrace tunnels. This is safer with
easier access when the level of the tailrace is as low as possible. A lower than normal minimum flow over the
spillway will allow the contractor more consistent access to the tailrace tunnel which will help complete the
work more quickly. This work will require 4 to 6 weeks to complete, assuming the weather cooperates.

As you know, inflow to Blewett Falls is primarily from releases at Tillery and flow from Rocky River. Tillery’s releases
will need to be altered during this time but we’re not exactly sure how we’ll need to operate Tillery to balance inflow
to Blewett Falls. We need to adjust the inflow arrival and recession times to accommodate being in the study area
and tailrace with a stable minimal flow condition over the spillway. This static minimum flow condition will be
required starting in the morning and not increasing until we’re out of the tailrace, in the late afternoon. We’ll need a
few days to adjust operations schedules at Tillery to stabilize inflow to Blewett Falls.

Obviously, we want to complete these two tasks simultaneously to minimize the amount of time the flow will be
below the 1,200 minimum flow currently required by the license. Each day, there will a be period when the
minimum flow will be above the 1,200 cfs when the flow from Tillery’s generation arrives but it will fall below the
1,200 cfs while the workers are in the tailrace. We cannot say with certainty what the minimum flow will be during
the period of work/study but with inflow from Rocky and leakage, we do not believe it would be below 300 cfs. We
would like to start releasing the lower minimum flow in mid-July and we should be back to normal by the end of
August. Of course, all of this is dependent on the weather. If we have a dry period, we can likely accomplish the
work before the end of August.

In summary, we will be requesting FERC approval of a planned minimum flow deviation below the required 1,200 cfs
at Blewett Falls beginning in mid-July, in order to complete the required Gravel Recruitment Study and sealing the
cracks in the powerhouse. This is a lot of info for an email so please call me at 704.382.0293 (office) or 704.641.3832
(cell) if you would like to discuss this further. Also, please reply to this email and let me know if you support our plan
to temporarily modify the minimum flow below Blewett Falls.

Best regards,
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties.
EXTERNAL EMAIL: Do not click any links or open any attachments unless you trust the sender and know the content
is safe.
From:Elizabeth Miller
To:Styer, Tami; Goudreau, Chris J.; Tarver, Fred; Mcdaniel, Chonticha; fritz.rohde; Twyla Cheatwood; Andrew Herndon ; John Ellis
Cc:Dunn, Lynne; Scott, David; Abney, Michael A
Subject:RE: [External] Blewett Falls Temporary Minimum Flow Modification Request
Date:Wednesday, July 3, 2019 4:11:07 PM
Attachments:image005.png
image007.png
Hi Tami,
SCDNR is okay with the plan moving forward in order to repair the Blewett Falls powerhouse and complete the
Gravel Recruitment Study. Thank you for allowing us the opportunity to comment and express our concerns.

Elizabeth C. Miller
SCDNR
Office: [phone]

From: Styer, Tami <[e-mail]>
Sent: Wednesday, July 3, 2019 3:28 PM
To: Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: [WARNING: UNSCANNABLE EXTRACTION FAILED]RE: [External] Blewett Falls Temporary Minimum Flow
Modification Request

Thank you for calling in on our conference call today to discuss the Blewett Falls
minimum flow deviation request. To help explain our plan, I provided the graph below
to show the relationship between the generation at Tillery, the Blewett Falls lake level
and the flow at the Hwy 74 Bridge below Blewett Falls.

As we discussed, the minimum flow from Tillery during the evening hours is typically
around 800 cfs. The minimum flow can be as low as 500 to 600 cfs during the day.
These minimum releases should result in a minimum flow at Blewett Falls of 700 to
1000 cfs (taking into account evaporation, leakage and inflow from Rocky River).
Below is a summary of the action items from our call today.

To accommodate the work under the powerhouse and the Gravel Recruitment Study,
Duke Energy will do the following:
Adjust the generation schedule at Tillery to provide a lower flow over the spillway
at Blewett Falls during the daylight hours. As soon as we determine this
generation schedule, we’ll send the agencies an update on what we expect the
Blewett Falls minimum flow to be.
On a weekly basis, we’ll provide monitoring of the Blewett Falls tailrace for signs
of stressed or dead fish. If the flow in the tailrace falls below 700 cfs, we’ll provide
this monitoring daily.
Provide weekly updates to the agencies on the status of the flow releases and
water quality by sending data from the USGS gage in the Tillery tailrace
(0212378405), in the Blewett Falls tailrace (0212880025), Highway 74 gage
(02129000) and the gage at Jones Creek Shoal (02129375).

I plan to send FERC a request for approval of the minimum flow deviation to start the
week of 7/15. I’m not sure if we can get approval that quickly but we’ll plan to start
with the testing as soon as we receive approval. Please provide an email and let me
know if you support our plan. I will include this in the request to FERC as the required
consultation.

Thanks again for your cooperation and quick response to our request.

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Styer, Tami
Sent: Tuesday, July 2, 2019 2:25 PM
To: Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

Thanks Chris. That’s a very good point. I obviously forgot about Tillery’s min flow
requirement when I said the lowest flow going over the spillway at Blewett Falls would
be 300 cfs. That assumes just leakage through Blewett Falls and inflow from Rocky
River. With Tillery’s minimum flow, which is usually around 400 cfs, the min flow over
the Blewett Falls spillway should be between 600 and 700 cfs. I can see why you
would be concerned that there would be no flow out of Tillery but that is not the case.
We are not planning to modify Tillery’s minimum flow requirement, only the time of
day we generate.

We can discuss this in more detail tomorrow.
Thanks again!
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Goudreau, Chris J. [mailto:[e-mail]]
Sent: Tuesday, July 2, 2019 12:34 PM
To: Styer, Tami <[e-mail]>; Elizabeth Miller <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

I can do a call anytime tomorrow and probably Friday.

My concern is not only the Blewett tailwater, but also the Tillery reach. I’m wondering if Tillery might run the min
flow for longer hours than normal; that would also boost temps in that reach, depending on the time of day. I’d like
to hear first-hand how both developments will be operated.

And thanks for the reminder about the WQ gage below Blewett.

From: Styer, Tami <[e-mail]>
Sent: Tuesday, July 02, 2019 12:16 PM
To: Elizabeth Miller <[e-mail]>; Goudreau, Chris J. <[e-mail]>; Tarver, Fred
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

Thanks everyone for your quick review of the note. I would be glad to set up a
conference call to discuss. Let me offer the following additional info and if you still
would like to discuss, would you be available this afternoon? Let’s say 3pm? I’m also
available tomorrow all day except 10-11am and all day Friday.

Additional Information
Under normal operations at Blewett Falls, we provide the minimum flow with
generation and utilize vent valves to provide additional aeration, when needed to meet
the water quality standard. Given that we have no operational units at Blewett Falls,
we have no way to enhance or manage the water quality. It will be whatever the
natural conditions are with the water going over the spillway. Please recall the
notification we sent to FERC on Feb 6, 2019 (attached), and their response on Mar 20
(also attached).

There has been one instance so far this year where the DO value was below the
minimum standard of 4.0 mg/l (see below). Chris, this gage is in the tailrace
(0212880025). What we’ve seen so far this year is that the DO values recorded during
the day are higher and they decline at night. By providing the higher min flow in the
late afternoon early evening, which is when the generation flow from Tillery should
arrive at Blewett Falls, we hope it will provide additional flow to help the DO levels in
the river stay above the standard. The lower minimum flow during the day may result
in lower DO values but without the generating units, the only potential to enhance the
DO would be to increase the flow over the spillway, but this would prevent the use of
the barge to seal the cracks in the powerhouse.

We believe this is the best opportunity to do both the Gravel Recruitment Study and
seal the cracks in the powerhouse even though it is a hotter time of the year. We
need to get this work completed to complete restoration of the powerhouse. If we wait
until the fall when the DO values are typically higher, that usually coincides with higher
inflow which would make it very difficult with limited access under the powerhouse.

Providing the lower flow now will allow us to get the work completed faster and we’ll
be taking advantage of what is already a not-so-great situation because without the
generating units operational, the DO is limited to whatever the natural conditions are
in the river.

I hope this helps. If you would still like to have a call, please let me know what time
works best and I’ll send out a meeting notice.
Thanks again for your quick response!
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

From: Elizabeth Miller [mailto:[e-mail]]
Sent: Tuesday, July 2, 2019 11:15 AM
To: Goudreau, Chris J. <[e-mail]>; Tarver, Fred <[e-mail]>; Styer, Tami
<[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

*** Exercise caution. This is an EXTERNAL email. DO NOT open
attachments or click links from unknown senders or unexpected
email. ***
Tami,
I have some concerns regarding the seasonal timing of the low flow period as well. I would also appreciate further
discussions to understand the potential impacts and evaluate means to minimize the impacts to the system. I can be
available for a conference call this week if that works for others.
Thanks,

Elizabeth C. Miller
SCDNR
Office: [phone]

From: Goudreau, Chris J. <[e-mail]>
Sent: Tuesday, July 2, 2019 11:06 AM
To: Tarver, Fred <[e-mail]>; Styer, Tami <[e-mail]>; Mcdaniel, Chonticha
<[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde <[e-mail]>;
Twyla Cheatwood <[e-mail]>; Andrew Herndon <[e-mail]>; John Ellis
<[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

I am wondering the same thing. This is the hottest time of year, so holding flows are very low levels during the
middle of the day will result in very high temps. Also, I’m guessing that Blewett can’t do anything to boost dissolved
oxygen, so there may be issues with that.

I just downloaded data from USGS gage below Tillery – means for last 30 days and instantaneous (15-min) for past 4
days. Unfortunately, the gage below Blewett doesn’t record WQ data, but I suspect a similar situation.

I’d like to discuss this in more detail. Can we set up a conference call?

From: Tarver, Fred
Sent: Tuesday, July 02, 2019 10:01 AM
To: Styer, Tami <[e-mail]>; Mcdaniel, Chonticha <[e-mail]>;
Goudreau, Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde
<[e-mail]>; Twyla Cheatwood <[e-mail]>; Andrew Herndon
<[e-mail]>; John Ellis <[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: RE: [External] Blewett Falls Temporary Minimum Flow Modification Request

Tami,
What is Duke’s level of confidence that it can meet WQ standards during this period?
Fred

Fred R Tarver III
Environmental Flows Program Consultant
Water Planning Section - Basin Plannning Branch
Department of Environmental Quality

919-707-9029 office
[e-mail]

Division of Water Resources
1611 Mail Service Center
Raleigh NC 27699-1611

Email correspondence to & from this address is subject to the N.C. Public Records Law & may be disclosed to third
parties!

From: Styer, Tami <[e-mail]>
Sent: Tuesday, July 02, 2019 9:04 AM
To: Tarver, Fred <[e-mail]>; Mcdaniel, Chonticha <[e-mail]>; Goudreau,
Chris J. <[e-mail]>; Elizabeth Miller <[e-mail]>; fritz.rohde <[e-mail]>;
Twyla Cheatwood <[e-mail]>; Andrew Herndon <[e-mail]>; John Ellis
<[e-mail]>
Cc: Dunn, Lynne <[e-mail]>; Scott, David <[e-mail]>; Abney, Michael A
<[e-mail]>
Subject: [External] Blewett Falls Temporary Minimum Flow Modification Request

CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]

Hello Everyone,
As you know, we are in the process of restoring the generating units at Blewett Falls that were flooded last fall during
Hurricane Florence. I’m sending this note as consultation on the need to provide a lower than normal minimum flow
at Blewett Falls for 4 to 6 weeks this summer. Our current minimum flow requirement is 1,200 cfs. Below is an
explanation of the tasks that need to be accomplished during this lower flow period.

1. In the 401 Water Quality Certification, we are required to complete a Gravel Recruitment Study within 5 years
of receiving the new license. The study consists of mapping the substrate in the tailrace down to Highway 74
Bridge. This study is required to duplicate a study done during relicensing, when leakage flow was being
released as the minimum flow from Blewett Falls. Without the generating units operational, we cannot get
the lake below the crest of the dam so we cannot duplicate leakage flow only, but we think we can complete
the study with minimal flow over the spillway.

2. Restoration of the units is continuing and one task to be completed is sealing the cracks in the powerhouse.
This will be done using a barge with access to the powerhouse through the tailrace tunnels. This is safer with
easier access when the level of the tailrace is as low as possible. A lower than normal minimum flow over the
spillway will allow the contractor more consistent access to the tailrace tunnel which will help complete the
work more quickly. This work will require 4 to 6 weeks to complete, assuming the weather cooperates.

As you know, inflow to Blewett Falls is primarily from releases at Tillery and flow from Rocky River. Tillery’s releases
will need to be altered during this time but we’re not exactly sure how we’ll need to operate Tillery to balance inflow
to Blewett Falls. We need to adjust the inflow arrival and recession times to accommodate being in the study area
and tailrace with a stable minimal flow condition over the spillway. This static minimum flow condition will be
required starting in the morning and not increasing until we’re out of the tailrace, in the late afternoon. We’ll need a
few days to adjust operations schedules at Tillery to stabilize inflow to Blewett Falls.

Obviously, we want to complete these two tasks simultaneously to minimize the amount of time the flow will be
below the 1,200 minimum flow currently required by the license. Each day, there will a be period when the
minimum flow will be above the 1,200 cfs when the flow from Tillery’s generation arrives but it will fall below the
1,200 cfs while the workers are in the tailrace. We cannot say with certainty what the minimum flow will be during
the period of work/study but with inflow from Rocky and leakage, we do not believe it would be below 300 cfs. We
would like to start releasing the lower minimum flow in mid-July and we should be back to normal by the end of
August. Of course, all of this is dependent on the weather. If we have a dry period, we can likely accomplish the
work before the end of August.

In summary, we will be requesting FERC approval of a planned minimum flow deviation below the required 1,200 cfs
at Blewett Falls beginning in mid-July, in order to complete the required Gravel Recruitment Study and sealing the
cracks in the powerhouse. This is a lot of info for an email so please call me at 704.382.0293 (office) or 704.641.3832
(cell) if you would like to discuss this further. Also, please reply to this email and let me know if you support our plan
to temporarily modify the minimum flow below Blewett Falls.

Best regards,
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office

Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties.
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EXTERNAL EMAIL: Do not click any links or open any attachments unless you trust the sender and know the content is
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From:Ellis, John
To:Fritz Rohde - NOAA Federal
Cc:Styer, Tami; Fred Tarver ([e-mail]); Mcdaniel, Chonticha; Chris Goudreau
([e-mail]); Elizabeth Miller; Twyla Cheatwood; Andrew Herndon; Dunn, Lynne; Scott,
David; Abney, Michael A
Subject:Re: [EXTERNAL] Re: Blewett Falls Temporary Minimum Flow Modification Request
Date:Tuesday, July 2, 2019 9:54:36 AM
*** Exercise caution. This is an EXTERNAL email. DO
NOT open attachments or click links from unknown
senders or unexpected email. ***
Tami,
The USFWS supports the request.
John Ellis
On Tue, Jul 2, 2019 at 9:36 AM Fritz Rohde - NOAA Federal <[e-mail]> wrote:
Tami
NMFS supports your request for the temporary minimum flow modification.
Fritz Rohde
NMFS-HCD
Beaufort, NC
On Tue, Jul 2, 2019 at 9:04 AM Styer, Tami <[e-mail]> wrote:
Hello Everyone,
As you know, we are in the process of restoring the generating units at Blewett Falls that were
flooded last fall during Hurricane Florence. I’m sending this note as consultation on the need to
provide a lower than normal minimum flow at Blewett Falls for 4 to 6 weeks this summer. Our
current minimum flow requirement is 1,200 cfs. Below is an explanation of the tasks that need
to be accomplished during this lower flow period.

1. In the 401 Water Quality Certification, we are required to complete a Gravel Recruitment
Study within 5 years of receiving the new license. The study consists of mapping the
substrate in the tailrace down to Highway 74 Bridge. This study is required to duplicate a
study done during relicensing, when leakage flow was being released as the minimum
flow from Blewett Falls. Without the generating units operational, we cannot get the lake
below the crest of the dam so we cannot duplicate leakage flow only, but we think we can
complete the study with minimal flow over the spillway.

2. Restoration of the units is continuing and one task to be completed is sealing the cracks in
the powerhouse. This will be done using a barge with access to the powerhouse through
the tailrace tunnels. This is safer with easier access when the level of the tailrace is as low
as possible. A lower than normal minimum flow over the spillway will allow the
contractor more consistent access to the tailrace tunnel which will help complete the
work more quickly. This work will require 4 to 6 weeks to complete, assuming the
weather cooperates.

As you know, inflow to Blewett Falls is primarily from releases at Tillery and flow from Rocky
River. Tillery’s releases will need to be altered during this time but we’re not exactly sure how
we’ll need to operate Tillery to balance inflow to Blewett Falls. We need to adjust the inflow
arrival and recession times to accommodate being in the study area and tailrace with a stable
minimal flow condition over the spillway. This static minimum flow condition will be required
starting in the morning and not increasing until we’re out of the tailrace, in the late afternoon.
We’ll need a few days to adjust operations schedules at Tillery to stabilize inflow to Blewett
Falls.

Obviously, we want to complete these two tasks simultaneously to minimize the amount of time
the flow will be below the 1,200 minimum flow currently required by the license. Each day,
there will a be period when the minimum flow will be above the 1,200 cfs when the flow from
Tillery’s generation arrives but it will fall below the 1,200 cfs while the workers are in the
tailrace. We cannot say with certainty what the minimum flow will be during the period of
work/study but with inflow from Rocky and leakage, we do not believe it would be below 300
cfs. We would like to start releasing the lower minimum flow in mid-July and we should be back
to normal by the end of August. Of course, all of this is dependent on the weather. If we have a
dry period, we can likely accomplish the work before the end of August.

In summary, we will be requesting FERC approval of a planned minimum flow deviation below
the required 1,200 cfs at Blewett Falls beginning in mid-July, in order to complete the required
Gravel Recruitment Study and sealing the cracks in the powerhouse. This is a lot of info for an
email so please call me at 704.382.0293 (office) or 704.641.3832 (cell) if you would like to
discuss this further. Also, please reply to this email and let me know if you support our plan to
temporarily modify the minimum flow below Blewett Falls.

Best regards,
Tami

Tami Styer, Project Manager II
Water Strategy and Hydro Licensing
526 S. Church St.
Charlotte, NC 28202
[phone] office