20080915 Ver 1_Notice of Mod of Minimum Flow Release_20160201

Strickland, Bev
From:Oakley, Mark <[e-mail]>
Sent:Monday, February 01, 2016 3:19 PM
To:Tarver, Fred; Higgins, Karen; Goudreau, Chris J.; [e-mail]
Subject:Notification of Modification of Munimum Flow Release - Bridgewater Hydro
Attachments:Modification of Min Flow - BW Jan 2016.pdf
The attached notification filed with the Federal Energy Regulatory Commission today describes a brief (approximately 30
minute) period during which the continuous minimum flow release at Bridgewater Hydro dropped slightly below the
required 145 cfs.

This event is addressed under the Incidental Maintenance provision of the MEP and by copy of this e-mail Duke Energy is
providing notifications to the appropriate resource agencies as identified in Maintenance and Emergency Protocol
Abnormal Condition A.2 – Unscheduled Hydro Unit Maintenance. This notification is also in accordance with Condition 9
of the NC water quality certification (license Appendix A).

Consultation is not required for Incidental Maintenance situations, however, I’ll be glad to answer further questions, if
any.

1

('DUKE
ENERGY.
February 1, 2016
The Honorable Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, DC 20426
RE: Notification of Modification of Flow Release
Catawba-Wateree Hydro Project P-2232
Dear Secretary Bose:
WATER STRATEGY, HYDRO
LICENSING AND LAKE SERVICES
Duke Energy Corporation
526 South Church Street
Charlotte, NC 28202
Mailing Address:
EC12Y / PO Box 1006
Duke Energy Carolinas, LLC (Duke Energy) is providing notification of a modification of flow releases in
accordance with Appendix E, Section A-4.0, Maintenance and Emergency Protocol Article (MEP) of the
Federal Energy Regulatory Commission (Commission) License for the Catawba-Wateree Hydro Project
(Project) issued November 25, 2015.
On January 27, 2016 Duke Energy had to switch to an auxiliary transformer at the Bridgewater
Development for maintenance purposes, requiring a shutdown of all generating units. Duke Energy
opened a flow release valve located in the Bridgewater Powerhouse to deliver required continuous
minimum flows during this time. During the transition between generation flow release and release
through the flow release valve, there was a brief (approximately 30 minute) period during which the
continuous minimum flow release dropped slightly below the required 145 cfs (Enclosure 1).
Duke Energy believes this situation occurred because the flow through the flow release valve had not
stabilized before shutting off the minimum flow generating unit. In the future, Duke Energy will make
sure flow through the release valve has stabilized prior to shutting off generating units.
This event is addressed under the Incidental Maintenance provision of the MEP and Duke Energy has
provided notifications to the appropriate resource agencies as required by MEP Abnormal Condition A.2
— Unscheduled Hydro Unit Maintenance. Consultation is not required for Incidental Maintenance
situations.
Please direct questions to Mark Oakley at [phone] ([e-mail]).
Si erely,
r -
Jeffrey G. ineberger, P
Director, Water Strateg and Hydro Licensing
Duke Energy Carolinas, L C
Enclosure

Enclosure 1 — Bridgewater Tailrace Flow on 27 January 2016
Normal Continuous Minimum Flow 145 cubic feet per second (cfs)
Values Below Minimum Flow Highlighted in Red
Date/Time
Flow (cfs)
1/27/16 2:00 PM
166.0
1/27/16 2:15 PM
164.0
1/27/16 2:30 PM
161.0
1/27/16 2:45 PM
121.0
1/27/16 3:00 PM
118.0
1/27/16 3:15 PM
121.0
1/27/16 3:30 PM
164.0
1/27/16 3:45 PM
164.0
1/27/16 4:00 PM
164.0