holt hydroelectric project - alabama power company...1.0 introduction the holt hydroelectric project...

EXHIBIT B PROJECT OPERATIONS

HOLT HYDROELECTRIC PROJECT FERC NO. 2203

DRAFT LICENSE APPLICATION

Alabama Power Company Birmingham, Alabama

Prepared by:

July 2012


HOLT HYDROELECTRIC PROJECT FERC NO. 2203


ALABAMA POWER COMPANY BIRMINGHAM, ALABAMA

Prepared by:

July 2012

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HOLT HYDROELECTRIC PROJECT

FERC NO. 2203



TABLE OF CONTENTS

1.0 INTRODUCTION ...............................................................................................................1

2.0 HOLT HYDROELECTRIC PROJECT ...............................................................................2 2.1 PROJECT OPERATIONS ...............................................................................................2

2.1.1 PROJECT OPERATIONS ...................................................................................2 2.1.2 PROTECTION, MITIGATION, AND ENHANCEMENT (PME) MEASURES ............3

2.1.2.1 EXHIBIT G MAP REVISIONS ....................................................... 3 2.1.2.2 CONDUCT WATER QUALITY MONITORING TO COMPLY

WITH THE REQUIREMENTS OF THE 401 WATER QUALITY CERTIFICATION .......................................................................... 4

2.1.2.3 CONTINUE LIGHT MAINTENANCE OF THE OVERLOOK PARK AND CONTINUE DISCUSSIONS WITH USACE AND ADCNR..................................................................................... 5

2.1.2.4 MAINTENANCE OF THE TRANSMISSION LINE.............................. 5 2.2 ESTIMATE OF CAPACITY AND GENERATION ..............................................................6

2.2.1 DEPENDABLE CAPACITY AND AVERAGE ANNUAL GENERATION ..................6 2.2.2 PROJECT FLOWS ............................................................................................6 2.2.3 FLOW DURATION CURVES ............................................................................7 2.2.4 AREA CAPACITY RELATIONSHIP ...................................................................7 2.2.5 POWER PLANT HYDRAULIC CAPACITY .........................................................7 2.2.6 TAILWATER CURVE ......................................................................................8 2.2.7 PLANT CAPABILITY .......................................................................................8 2.2.8 APPLICANT’S PLANS FOR FUTURE DEVELOPMENT ........................................9

3.0 LITERATURE CITED ......................................................................................................10

LIST OF FIGURES FIGURE B-1 BEFORE HOLT CONSTRUCTION .................................................................................4 FIGURE B-2 HOLT AFTER CONSTRUCTION ...................................................................................4 FIGURE B-3 HOLT AFTER CONSTRUCTION ...................................................................................7 FIGURE B-4 TAILWATER RATING CURVE .....................................................................................8 FIGURE B-5 PLANT CAPACITY CURVE ..........................................................................................9

TABLE OF CONTENTS (CONT’D.)

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LIST OF TABLES

TABLE B-1 MEAN, MAXIMUM AND MINIMUM MONTHLY FLOW STATISTICS FOR THE BLACK WARRIOR RIVER IN THE PROJECT AREA ........................................................6

LIST OF APPENDICES

APPENDIX A FIGURES J:\535\016\Docs\Exhibits\Exhibit B 07-19-12.doc

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HOLT HYDROELECTRIC PROJECT

FERC NO. 2203



1.0 INTRODUCTION

The Holt Hydroelectric Project (Project) is comprised of an existing, licensed hydroelectric

facility owned and operated by Alabama Power Company (Alabama Power) and is located on the

Black Warrior River at the U. S. Army Corps of Engineers (USACE) Holt Lock and Dam in

Tuscaloosa County, Alabama. The Project has an electric generating capacity of 46.9 megawatts

(MW). This exhibit provides a detailed description of Project operations in accordance with

Federal Energy Regulatory (FERC) requirements at C.F.R. Section 5.6 and 4.51(c).

The Project is an important component of Alabama Power’s power generation system. Project

generation is necessary in both the short and long term to maintain electric system reliability,

operational flexibility, black start ability, and low cost electricity for Alabama Power customers.

Project generation represents a valuable portion of Alabama Power’s total generation production

and power generated by the Project is transmitted and sold to Alabama Power's customers.

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2.0 HOLT HYDROELECTRIC PROJECT

2.1 PROJECT OPERATIONS

2.1.1 PROJECT OPERATIONS

Alabama Power operates the Project based on the USACE’s management of Holt Lake.

USACE’s first priority at the Holt Lock and Dam is to support river navigation. Alabama Power

operates the Project using excess water provided by USACE. Since the electrical generation at

the Project is considered secondary to the USACE’s navigation use, the Project has operational

restrictions from the USACE to which Alabama Power must adhere, as described below:

POOL LEVEL

Limiting elevations for reservoir operation are a maximum of 187 ft msl and a minimum of 186

ft msl, and the reservoir will normally be maintained between these levels. Because of navigation

requirements, based on channel depths in the upper end of the reservoir, the pool must not be

drawn down below elevation 186 ft msl. The upper limit of 187 ft msl will not be exceeded,

except during floods when inflows exceed the full discharge capacity of the project, unless

otherwise directed by the Reservoir Regulation Section.

OPERATION FOR NAVIGATION

The reservoir will be operated to provide 9-foot depths in the navigation channel which extends

approximately 19 miles upstream to Bankhead Lock and Dam. It is expected that very little

maintenance dredging will be required and in general the 9-foot depth will be provided by

controlling the reservoir level at or above elevation 186 ft msl, the lower limit of drawdown.

FLOOD CONTROL OPERATIONS

There is no flood control in the Project; the USACE does implement flood control operations.

During floods, the Holt reservoir will be held at maximum operating pool, elevation 187 ft msl,

by passing the inflow through the spillway gates and/or the power plant until the full discharge

capacity of the spillway is reached. When the full capacity of the spillway is reached, free

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overflow with all gates fully opened will prevail until the reservoir peaks and recedes to

elevation 187 ft msl.

2.1.2 PROTECTION, MITIGATION, AND ENHANCEMENT (PME) MEASURES

2.1.2.1 EXHIBIT G MAP REVISIONS

The existing Holt Project Boundary map, formerly Exhibit K, is being revised to file as Exhibit

G, to reflect what actually occurred in erecting the Holt-Holt (Holt) Transmission Line (TL)

during initial construction. Figure B-1 (Before Holt Construction) shows the original proposal to

erect the Holt TL in red (the proposed towers are marked as red circles). The existing Holt-

Gorgas (Gorgas) TL is shown in black and the existing towers are marked as black circles.

During the initial construction of the Holt TL, Alabama Power suspected that that there may be

high voltage interference with the proposed Holt TL as it intersected with the existing Gorgas

TL.

To resolve the high voltage interference, Alabama Power placed the Holt TL on the existing

Gorgas towers (marked as black circles) in Figure B-2 (Holt After Construction). The Holt-

Gorgas line was actually placed where the initial proposed Holt TL is depicted (red circles). The

placement of the Holt TL was not updated on the Exhibit K maps after construction; therefore,

Alabama Power proposes to correct and file revised Exhibit G maps to reflect the existing Holt

TL. Correcting the Project Boundary will involve removing 3.8 acres and adding 7.3 acres. The

removed and added lands are privately owned and Alabama Power has retained the necessary

rights to use these lands for Project purposes.

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FIGURE B-1 BEFORE HOLT CONSTRUCTION

FIGURE B-2 HOLT AFTER CONSTRUCTION

2.1.2.2 CONDUCT WATER QUALITY MONITORING TO COMPLY WITH THE REQUIREMENTS OF THE 401 WATER QUALITY CERTIFICATION

Alabama Power proposes to collect dissolved oxygen (DO) and temperature data for two years

following issuance of the new FERC license in accordance with a water quality monitoring plan.

If the monitoring results do not indicate substantial compliance with the state water quality

standard for DO (maintenance of a DO concentration of 4.0 mg/l or greater in turbine releases),

Alabama Power will develop and implement additional measures to increase DO in the releases

from the Project through structural or operational modifications. These measures provide

reasonable assurance that the DO standard of 4.0 mg/l will be met at the Project.

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Alabama Power will record DO concentrations and water temperature at 60-minute intervals

during periods of generation following one continuous hour of generation beginning June 1 and

extending through September 30 each year. During flood events, the monitoring may be

temporarily discontinued until tailrace elevations return to normal.

The turbine aeration system will be automatically activated when the intake DO concentration

declines to less than or equal to 4.5 mg/l or less. When the DO concentration rises to 5.0 mg/l or

greater, the aeration system will automatically terminate. The DO in the Holt tailrace will be

calculated as the sum of the incoming DO concentration plus the increase in DO concentration

by the turbine aeration system when it is activated (+0.25 mg/l).

Annual DO monitoring reports will be submitted with appropriate certifications to the Alabama

Department of Environmental Management (ADEM) 90 days following the cessation of

monitoring. Following the final year of monitoring, the complete set of data will be submitted to

ADEM for review and comment prior to submittal to the FERC.

2.1.2.3 CONTINUE LIGHT MAINTENANCE OF THE OVERLOOK PARK AND CONTINUE DISCUSSIONS WITH USACE AND ADCNR

Alabama Power proposes to continue operating and maintaining the recreation area (Overlook

Park and picnic tables) at the Scenic Overlook near the powerhouse. Alabama Power will mow

the grass at the Overlook Park, empty the trash cans, maintain the picnic tables, and preserve the

security (lock the gates) of the Overlook Park. In addition, Alabama Power will continue

discussions with the USACE and ADCNR regarding opportunities to provide additional

recreation access in the tailrace area.

2.1.2.4 MAINTENANCE OF THE TRANSMISSION LINE

Alabama Power will maintain the transmission lines at the Project. Alabama Power will remove

dangerous trees, trim the side of the area, mow the grass, and apply herbicide as needed in

accordance with applicable application guidelines.

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2.2 ESTIMATE OF CAPACITY AND GENERATION

2.2.1 DEPENDABLE CAPACITY AND AVERAGE ANNUAL GENERATION

The Project has a dependable capacity of 46.9 MW. The 10 yr historical average annual energy

production is 158,629,700 KWh. The Project will consume approximately 394,000 KWh

annually in station service.

2.2.2 PROJECT FLOWS

Maximum monthly flow in the Black Warrior River has historically occurred in March, while the

minimum monthly flow has historically occurred in October. Mean, maximum, and minimum

monthly flow statistics for the Project, as recorded at the Holt Lock and Dam gage, are presented

in Table B-1. The peak instantaneous daily flow at the Holt Lock and Dam gage was 178,000 cfs

on April 13, 1979 (United States Geological Survey (USGS), 2012).

TABLE B-1 MEAN, MAXIMUM AND MINIMUM MONTHLY FLOW STATISTICS FOR THE

BLACK WARRIOR RIVER IN THE PROJECT AREA (Source: USGS Gage No. 02462951 – Holt Lock and Dam (Period of Record: 1976-2011, 2012))

MONTH MEAN

DISCHARGE (CFS)

MAXIMUM DISCHARGE

(CFS)

MINIMUM DISCHARGE

(CFS) January 12,400 26,030 941.3 February 13,400 46,480 2,869 March 15,300 38,490 2,560 April 11,500 26,820 952.0 May 7,490 33,160 484.8 June 4,160 24,760 787.9 July 3,490 17,140 1,244 August 2,210 4,800 1,203 September 2,970 11,460 864.4 October 2,700 19,010 99.6 November 4,670 20,630 57.7 December 8,520 27,650 98.7

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2.2.3 FLOW DURATION CURVES

Monthly flow duration curves are provided in Appendix A.

2.2.4 AREA CAPACITY RELATIONSHIP

Figure B-3 shows the area-capacity relationship for the Holt reservoir, which is operated by the

USACE.

FIGURE B-3 HOLT AFTER CONSTRUCTION

2.2.5 POWER PLANT HYDRAULIC CAPACITY

Holt Project has one 6-blade vertical “diagonal flow” design turbine. The flow off the turbine has

a diagonal pattern, and is also referred to as a “mixed-flow” turbine. A diagonal flow turbine is

somewhat of a mix between a Francis turbine and a propeller turbine. The diagonal flow turbine

has longer blades than a propeller, which results in the blades overlapping. The turbine has a

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rated minimum hydraulic capacity of 1,000 cfs, and rated maximum hydraulic capacity of 11,200

cfs1

2.2.6 TAILWATER CURVE

. Between 1984 and 2010, daily inflow into Holt Lake has exceeded maximum hydraulic

capacity approximately 16 % of the time. The total spillway capacity of the dam is 393,000 cfs at

pool elevation 187 ft msl, and 639,500 cfs at pool elevation 206.4 ft msl.

Figure B-4 shows the tailwater rating curve for the Project.

FIGURE B-4 TAILWATER RATING CURVE

2.2.7 PLANT CAPABILITY

The plant capability is the plant output, in megawatts, over a range of gross heads. A curve

depicting the Project power plant capability in MW versus head is provided below (Figure B-5).

1 The actual minimum hydraulic capacity is 9,451 cfs (due to vibration) and actual maximum hydraulic capacity is

11, 044.

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Maximum (64 ft), normal (60 ft), and minimum (58 ft) heads are specified. The new turbine was

tested at the normal head of 60 ft (Figure B-5).

FIGURE B-5 PLANT CAPACITY CURVE

2.2.8 APPLICANT’S PLANS FOR FUTURE DEVELOPMENT

Alabama Power does not have any plans to develop any additional capacity at the Project.

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3.0 LITERATURE CITED

U.S. Geological Survey (USGS). 2012. http://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no =02462951, accessed April 20, 2012.

U.S. Geological Survey (USGS). 1976-2011, 2012. USGS Gage No. 02462951 – Holt Lock and Dam (Period of Record: 1976-2011, 2012. (www.nwis.waterdata.usgs.gov) accessed April 2012.

http://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no=02462951�

http://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no=02462951�

http://www.nwis.waterdata.usgs.gov/�

APPENDIX A

FIGURES

A-2

THE MONTHLY FLOW DURATION CURVES

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