overview of alabama power’s tallapoosa river operations

Overview of Alabama Power’s Tallapoosa River Operations

Martin Dam Relicensing Informational Meeting

April 1, 2008

Andy Sheppard, P.E.Project Mgr. - Hydro Optimization

What do we want to do today?

Take a brief tour of the river basin and dams

Review project purposes

Special operation issues

Daily operation considerations

Alabama Power Company Hydroelectric ProjectsAlabama Power Company Hydroelectric Projects

APCo RESERVOIR SYSTEMS

Three River Basins Tallapoosa Warrior Coosa

Drainage 3,300 4,200 10,100

Reservoirs 4 3 6

Units 11 4 26

Capacity (MW) 420 280 950

S

N

EW

Tallapoosa River Basin

$

$

$$Yates Dam

Harris Dam

Martin Dam

Thurlow Dam

5.45.0

7.0

5.5

4.23.8

4.8

3.64.4

2.7

3.7

5.2

0

2

4

6

8

1 2 3 4 5 6 7 8 9 10 11 12

MONTH

RAIN

(in

.)Tallapoosa River Basin Average Monthly

Rainfall

PROJECT PURPOSES

HYDRO ELECTRIC POWER Electric System Dynamic Benefits Energy

FLOOD CONTROL

DROUGHT MANAGEMENT

NAVIGATION REQUIREMENTS

RECREATION, FISH AND WILDLIFE

WATER QUALITY

The Reservoirs operated by APCo are different in more than just name and location, they're designed to be operated differently.

APCo operates two types of reservoirs : Run-of-River and Storage

Run-of-River Storage

Tallapoosa Yates, Thurlow Harris, Martin

Warrior Bankhead, Holt Smith

Coosa Lay, Mitchell, Jordan/Bouldin Weiss, Henry, Logan Martin

Furthermore, the dams located on the same river must be operated as a single system

The operations of each dam have an impact on both upstream and downstream reservoirs

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Time of Day

Genera

tion o

r L

oad

Typical APCo System Load and Hydro Generation during Winter

9,000 MW8,000 MW

7,100 MW

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Time of Day

Hydro Generatio

n

Typical APCo System Load & Hydro Generation during Summer

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Time of Day

Generatio

n or Load

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Time of Day

Hydro Generatio

n11,000 MW

6,300 MW

0

20

40

60

80

100

120

140

160

1985 1989 1993 1997 2001 2005

% Avg. MWh

Wadley May 2003

Tallapoosa River above Horseshoe Bend May 2003

Flood Control can be defined as reducing river stages DOWNSTREAM of a dam

The people and property located downstream benefit from flood control operations

Run-of-river reservoirs have limited flood control capability; they cannot provide this benefit to the public

Downstream flood peaks are reduced by discharging less water than is coming into the reservoir

Flood control plans are based on studies of significant rainfall events.

Not every flood can be completely controlled; each project has a particular amount of water that it can store

After all flood storage has been used, the project becomes run-of-river

Drought Forecasting

Drought Timetable

Reservoir Impacts

So, how does APCo make the decisions?

Using a consultation process that involves all the regulatory agencies responsible for managing flow and its impacts:

How bad . . . . How long . . . . . How much

License Excerpt for Martin DamFERC Project 349

• Article 12 - The FERC & Secretary of the Army have rights to dictate storage & discharge rules in the interest of navigation, protection of life, health, and property, and in the interest of the fullest practicable conservation and utilization of such waters for power purposes and for other beneficial public uses, including recreational purposes

(paraphrased)

Tallapoosa RiverDaily Reservoir Operations

Automated Rain & Stream Gages

RIVER RAIN STREAM

TALLAPOOSA 15 6

WARRIOR 15 6

COOSA 45 18

HARRIS HYDRO PROJECT Flood Control Guideline

780

782

784

786

788

790

792

794

796

MSL

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Daily & Weekly Load Forecast

Rain Forecast

Inflow Forecast

Lake Level Forecast

Units On-lineMaintenance Plans

Up & Down Stream Lake Levels & Inflows

Lake Activity

Required Min. Discharges

Flood Control Discharges

Operational Issues

Martin Rule Curve Evaluation

• Primary objective of MIG 3 Project Operations Study Plan is to determine feasibility of winter pool change

• Preliminary results of modeling complete, presented today

• Investigated early implementation approach – change and evaluate “in the field”

• Modeling results indicate downstream flooding issues

• Solicited direction from FERC – must conduct in-depth analysis of impacts and mitigation during relicensing process through modeling and studies prior to any operational changes

• Evaluation of permanent changes to winter pool will be conducted over the next 2 to 3 years and proposal included in license application in 2011

• Precedent has been set for addressing future drought conditions