J. STROM THURMOND DAM AND LAKE
GEORGIA AND SOUTH CAROLINA
VII - WATER CONTROL PLAN
T7-01. General Objectives .
The J. Strom Thurmond Project was the first of three multiple-purpose projects that the Federal Government built in the Savannah River Basin. This project, originally named the Clark Hill Project, was completed and began operation in 1952. The authorized purposes of the J. Strom Thurmond project are water supply, hydroelectric power, flood control, fish and wildlife, water quality and recreation. This water control management plan has been developed for the J. Strom Thurmond Dam and Lake multi-purpose project to conform with the objectives and specific provisions of the authorizing legislation for the Hartwell, Richard B. Russell and Thurmond projects and applicable Corps of Engineers directives.
T7-02 . Overall Plan for Water Control .
Water control management decisions at the J. Strom Thurmond Project take into account hydrologic and climatological factors, conditions at the upstream projects, needs of the downstream water users, potential threats of flood or drought, present and projected lake levels, and the constraints of recreation, fish management, water supply, water quality, and hydroelectric power production. Evaluation of these factors requires well-qualified, technically trained personnel with special experience in the field of modern hydrology, hydraulic engineering, and water control management. The Savannah District maintains this expertise in the Hydraulics Section of the Hydrology and Hydraulics Branch (the Water Control Center), with the assistance of fish and wildlife and recreation experts. Close coordination with the plant operators, whose experience and on-site location makes them a vital part of the water control team, is essential. The Savannah District reports water control conditions and activities to the South Atlantic Division (SAD) office in Atlanta.
The J. Strom Thurmond Project has 18 feet of conservation storage, from elevation 312 to 330 feet NGVD, which accounts for 1,045,000 acre feet of storage. The flood control storage available between 330 and 335 is 390,000 acre feet. The project has a seasonal drawdown of the flood control pool. The guide curve is shown in Plate T7.9. The area-capacity curve for the project is found at Plate T7.3 and the corresponding storage table is shown in Table T7-1.
a. System management . Decisions concerning water control for the Thurmond Project are part of a coordinated multi-reservoir system regulation for the Savannah River Basin, as well as part of the operation of the larger power network for the southeastern United States (coordinated through SAD).
b. Compatibility Among Purposes .
Fish and Wildlife or Water Quality and turbine or spillway releases for Flood Control : During flood control operations, passing inflow through the project may have negative impacts on water quality or fisheries, both within the lake and downstream.
Fish and Wildlife or Water Quality and turbine releases for Hydropower : During periods when the pool must be maintained at a constant level for such purposes as fish spawning, releases through the turbines for energy production may be curtailed or eliminated altogether, depending on inflows.
Recreation and Hydropower : Particularly during drought periods, potential exists for such a conflict. Continued power generation to meet contractual requirements for electrical power may cause pool elevations to fall to levels which adversely affect recreational uses of the lake. Boat ramps may no longer be functional, underwater hazards may become a danger to boaters, and formerly scenic areas may become unattractive.
Water Supply and Hydropower : Particularly during drought periods, potential exists for such a conflict. Continued power generation to meet contractual requirements may cause pool levels to fall below the elevations of the intake structures of the water users for Thurmond Lake.
Recreation and Flood Control : Due to the risk of flood damages and injuries, any necessary flood control regulation is given highest priority.
c. Normal Regulation Activities .
The Water Control Center is responsible for the long term planning and supervision of the operation of rainfall and river stage reporting. Weekly activities are as follows:
(1) Weekly Water Volume Analysis . The Water Control Manager compiles necessary basic data on precipitation, river stages, reservoir elevations, and general streamflow conditions. Using this data, the manager prepares inflow, discharge, storage and pool elevation projections for the following week, which is presented by noon each Wednesday. Water generation availability analyses and forecasts for the three reservoir system are also presented at this time. Projections are based on lake levels, lake level guide curves, power contract commitments, antecedent and expected rainfall, and rainfall-runoff relationships for the upper Savannah River Basin. Additional considerations which affect discharges are powerplant maintenance activities, proposed operational changes which would affect power generation, and water level management activities related to fisheries or recreation. Input concerning these matters is normally received on Wednesdays from the Planning Division and the Technical Support Branch of Operations Division.
(2) Weekly Report to the South Atlantic Division (SAD) . The weekly declaration of releases, the "Water Volume Analysis",is posted on the Water Management web site,http://water.sas.usace.army.mil, and is transmitted to the Water Management Branch of South Atlantic Division by the Water Control Center every Wednesday afternoon. The water control managers then consult with the Southeastern Power Administration (SEPA), the marketing agency for Federally generated power in the southeastern states.
(3) Weekly Meeting . Each Thursday morning the Water Control Manager conducts a meeting with Operations and Planning Division personnel to review storage and pool elevation projections and power generation availability analyses. The Water Control Manager transmits water control data (pool elevations, inflows, outflows, precipitation, hydrographs at downstream control points, and other hydrologic data) to SAD.
(4) Final Generation Schedule . Following confirmation by SEPA, SAD advises the Water Control Center each Friday of the amount of energy to be taken from each of the three projects. SEPA's customers (the power companies) furnish hourly schedules directly to the Project Operator with copies furnished to the Water Control Center.
T7-03 . Standing Instructions to the Project Operator .
A summary of reservoir regulation procedures for the project operator during both normal and emergency situations is found in Exhibit T7-A. During communication outages, unforeseen or emergency events, as well as periods of normal operation, standing instructions are essential to ensure efficient and safe operation of the project at all times. The operation instructions clearly outline the physical constraints, such as spillway/outlet work restrictions, based on design limitations.
The Hydraulics Section, Hydrology and Hydraulics Branch, Engineering Division, Savannah District, is responsible for water control management of the Savannah River Basin which includes the regulation of the J. Strom Thurmond Dam and Lake. Operations Division is responsible for the operation and maintenance of these projects. Assigning responsibility for water control management to the Hydraulics Section does not diminish the necessity for or the
desirability of appropriate and adequate inter-staff coordination. Hydraulics Section is responsible for insuring that such coordination has been effected and subsequent actions are taken. The project operators at each of the three dams are responsible to the water control manager for all water control actions.
Transmission of instructions from the water control manager through several individuals or organizational units can be a source of delay and misunderstandings. Clear lines of communication and authority must be maintained. Occasionally, water control management decisions necessitate that the water control manager (in Engineering Division) contact the project operator directly so that satisfactory instructions can be given or hydrologic data can be obtained. Particularly during time of emergencies, there must be no delay in transmission of instructions or hydrologic data between the project operator and the water control manager. In these instances, the project operator will act on instructions received directly from the water control manager on all matters regarding the regulation of water. Advisory notification is furnished to Operations Division as soon as possible.
T7-04 . Flood Control .
a. General . The objective of flood control regulation at the J. Strom Thurmond Project is to reduce flood damages to the lower Savannah River Basin the extent possible. Normal conditions exist when there is no flood, drought or other emergency and none is anticipated. Normal pool varies seasonally from elevation 326 to 330 feet NGVD. During the period between May and October 15th, the J. Strom Thurmond Project has 5 feet of flood control storage, from elevation 330 feet NGVD to 335 feet NGVD. The flood control storage available between 330 and 335 is 390,000 acre feet. Between October 15th and December 15th the pool is drawn down to a seasonal normal pool of 326 ft NGVD, to allow for the statistically higher winter and spring rainfall. This increases the available storage by 280,000 acre feet, to a total available storage of 670,000 acre feet. (see Table T7-1) From January to May, the normal pool is increased back to elevation 330. The guide curve is shown in Plate T7.9
b. Flood Regulation . Reservoir operation during flood conditions must be adjusted to account for variation in reservoir stage and quantity of rainfall runoff. Plate T7.4 contains detailed instructions for operations to fit the individual flood occurrence. All instructions pertaining to reservoir regulation for flood control are to come from the Savannah District. See the Table 5-3 for a listing of Savannah District flood control personnel and their telephone numbers.
The Water Control Manager performs flood routings and makes lake elevation and river stage forecasts, and coordinates and schedules lake releases during flood periods. Flood forecasting is accomplished using the Hydrologic Engineering Center (HEC) computer software HEC-1F, a rainfall model which uses real-time precipitation data to estimate inflows at the projects. HEC-5, an HEC model which simulates and analyzes the operation of reservoir systems, is a highly complex multi-purpose, multi-reservoir, multiple flood reservoir system simulation tool. The model is capable of evaluating a reservoir system to determine the best operation for water quantity and quality, evaluating operational concerns such as flood control, hydropower and water supply. Mod-5 is an interactive version of HEC-5, and will enable the Water Control Manager to model various release scenarios to best manage the projects
During floods, the Water Control Manager forwards reports as necessary to SAD containing data on predicted peak stages and percentage of flood control storage utilized. The Water Control Manager informs responsible District personnel on critical weather and streamflow conditions affecting the public and District activities, and coordinates with the public affairs office to issue flood reports on flood emergencies.
When the possibility of flooding conditions at or downstream of the reservoirs exists, the Savannah District Operations Division Readiness Branch (OP-E) is contacted. OP-E coordinates implementation of evacuation plans with local government agencies prior to any flood releases, notifies the City of Augusta of the possible need for stoplogs to be installed in the levee, and dispatches flood survey teams to affected areas and notifies local officials that District facilities and personnel are available upon request to assist in emergency conditions. The Water Control Manager furnishes a forecast of pool elevations and releases to be made to meet downstream flood control requirements to the Water Management Branch, SAD. At least one of the following SAD personnel will be contacted during a flood emergency:
|Mr. Chris Smith||Office||N/A|
|Mr. Trent Ferguson||Office||N/A|
STANDING INSTRUCTIONS TO THE PROJECT OPERATOR FOR WATER CONTROL
J. STROM THURMOND DAM AND LAKE PROJECT
1. BACKGROUND AND RESPONSIBILITIES
a. General Information . These "Standing Instructions to the Project Operator for Water Control" are written in compliance with Paragraph 9-2 of Engineering Manual 1110-2-3600 (Engineering and Design, MANAGEMENT OF WATER CONTROL SYSTEMS, 30 November 1987) and with Engineer Regulation 1110-2-240 (Engineering and Design, WATER CONTROL MANAGEMENT, 8 October 1982).
(1) Project Purposes . The operating purposes of the J. Strom Thurmond Project, are Recreation , Hydroelectric Power , Water Supply , Fish and Wildlife , Water Quality , and Flood Control .
(2) Chain of Command . The Project Operator is responsible to the Water Control Manager for all water control actions.
(3) Structure . The J. Strom Thurmond Dam is located at Savannah River Mile 221.6, Columbia County, Georgia and McCormick County, South Carolina. The dam is a concrete gravity and earth embankment structure with a concrete gravity ogee spillway. The Thurmond Powerhouse is located on the South Carolina (east) side, immediately downstream of the dam.
(4) Operations and Maintenance (O&M). All O&M activities are the responsibility of the U.S. Army Corps of Engineers.
b. Role of the Project Operator .
(1) Normal Conditions (dependent on day-to-day situation) . During normal conditions, all releases will be made through the turbine units. The water control manager will coordinate the weekly water control actions with SEPA. The Project Operator will then receive instructions from SEPA. This will be increased to a daily basis if the need develops. Any special instructions on the operation of the gates at New Savannah Bluff Lock and Dam will be received directly from the water control manager.
(2) Emergency Conditions (flood or drought) . The Project Operator will be instructed by water control managers on a daily or hourly basis for water Exhibit T7-A
STANDING INSTRUCTIONS TO THE PROJECT OPERATOR (Continued)
control actions during flood events and other emergency conditions. In the event that communications with water control managers are cut off during a flood event, the operator should regulate plant discharge in accordance with Plate T7.4, Flood Control Release Schedule, Plate T7.5, Spillway Gate Regulation Schedule, and Plate T7.6, Tainter Gate Rating Curves, and notify local civil defense authorities in the event that spillway releases are required.
2. DATA COLLECTION AND REPORTING .
a. Normal Conditions . Project data is recorded hourly by the project operator. The data is retrieved hourly by the Water Control Manager and loaded into the Water Control Data System. The data is subsequently made available on the Water Management web site at http://water.sas.usace.army.mil:
(1) Pool Elevations in feet NGVD are collected hourly.
(2) Basin Average Precipitation in hundredths of an inch is estimated hourly from NWS doppler radar.
(3) Tailwater Elevations in feet NGVD are collected hourly.
(4) Discharge in cubic feet per second is collected hourly.
(5) Inflow to the lake in cubic feet per second is collected hourly.
(6) Scheduled and Actual Generation in megawatt-hours is collected hourly.
b. Emergency Conditions . Report hourly the elevation, turbine discharge, spillway discharge, and general project status to the Water Control Manager.
c. Regional Hydro-meteorological Conditions . The Project Operator will be informed by the Water Control Manager of regional hydrometeorological conditions that may/will impact the structure.
3. WATER CONTROL ACTION AND REPORTING .
a. Normal Conditions . The Project Operator reports directly to the Water Control Manager.
b. Emergency Conditions . The Project Operator will follow the Savannah River Emergency Action Plan (District Pamphlet 1130-2-16, Appendix B) for emergency notification procedures.
c. Inquiries . All significant inquiries received by the Project Operator from citizens, constituents or interest groups regarding water control procedures or actions must be referred directly to the Water Control Manager.
d. Water Control Problems . The Project Operator must immediately notify the Water Control Manager, by the most rapid means available, in the event that an operational malfunction, erosion or other incident occurs that could impact project integrity in general, or water control capability in particular. Such incidents are discussed in Appendix A of DP 1130-2-16, the Emergency Action Plan.
J. STROM THURMOND DAM AND LAKE
|In the Piedmont Area at Latitude 33o - 39' N, Longitude 82o - 11' W|
|On the Savannah River:|
|221.6 miles above the mouth|
|207.2 miles above Savannah, Georgia|
|22.0 miles above Augusta, Georgia|
|37.5 miles below Richard B. Russell Dam|
|67.3 miles below Hartwell Dam|
|In Columbia County, Georgia and McCormick County, South Carolina 23 miles southeast of Augusta, Georgia|
|Above the mouth of the Savannah River||100||10,579|
|Above Augusta, Georgia (Butler Cr. gage)||71||7,508|
|Above J. Strom Thurmond Dam||58||6,144|
|Thurmond Local Basin||.||3254|
|Uncontrolled local area||(Thurmond Dam to Butler Creek)||1,364|
|STORAGE VOLUMES||Elevation (ft NGVD)||Acre-feet|
|Spillway design flood||344.7||3,700,000|
|Standard project flood||342.1||3,450,000|
|Flood control pool||335.0||2,900,000|
|Maximum conservation pool||330.0||2,510,000|
|Minimum conservation pool||312.0||1,465,000|
|Conservation storage, usable||312 to 330||1,045,000|
|Flood storage||330 to 335||390,000|
|Surcharge storage||335 to 346||920,000|
|Max Induced Surcharge Pool||346.0||98,500|
|Spillway design flood||344.7||94,700|
|Standard project flood||342.1||90,000|
|Flood control pool||335.0||78,500|
|Maximum conservation pool||330.0||72,000|
|Minimum conservation pool||312.0||45,000|
|DAM, SPILLWAY, INTAKE AND POOL ELEVATIONS|
|Top of dam||351.0|
|Maximum Observed Pool||336.46||4/11/1964|
|Minimum Observed Pool||296.4||2/03/1956|
|Spillway design flood||344.7|
|Induced surcharge pool||346.0|
|Standard project flood||342.1|
|Top of Tainter gates, closed||335.0|
|Flood control pool||335.0|
|Maximum conservation pool||330.0|
|Average conservation pool||327.5|
|Minimum conservation pool||312.0|
|Intake invert for Hydropower||228.0|
|Spillway bucket lip||(varies) 185.0|
|Elevation, bottom of sluice||190.0|
|Draft tube exit||160.0|
|Bottom of draft tube||154.0|
|Spillway design flood||255.0||1,055,000 cfs|
|Standard project flood||240.0||645,000 cfs|
|Powerhouse Design flood||240.0||645,000 cfs|
|Maximum tailwater of record (277,000 cfs)||220.5|
|7 units Operating at Average Head||193.0|
|1 units Operating at Average Head||185.0|
|Average Operating condition||191.0|
|DAM, SPILLWAY AND INTAKE DIMENSIONS|
|Concrete gravity and earth embankment with concrete gravity spillway|
|Length of concrete sections||2,282 feet|
|Length of earth embankment||3,398 feet|
|Maximum height of concrete section||200 feet|
|Maximum height of earth embankment||151 feet|
|Length of intake section||434 feet|
|Number of sluices||8|
|Width of sluices||4 feet|
|Height of sluices||9 feet|
|Gross length of spillway||1,096 feet|
|Length of clear opening||920 feet|
|Tainter gates (23)||each 40 feet wide by 35 feet high|
|Width of Gate||40 feet|
|Height of Gate||35 feet|
|Type of Bucket||Submerged Roller Bucket|
|Radius of bucket||50 feet|
|DESIGN FLOWS||Cubic feet per second|
|Standard Project Flood (SPF)|
|Peak Reservoir Inflow||645,000 cfs|
|Maximum Estimated Outflow||560,000 cfs|
|Spillway Design Flood|
|Peak Reservoir Inflow||1,180,000 cfs|
|Maximum Estimated Outflow||1,055,000 cfs|
|Conventional Operating Units||7||52 MW|
|Maximum net operating head||152 feet|
|Average operating head||136 feet|
|Minimum operation head||118 feet|
|Turbine capacity at average head||55,000 hp per unit|
|Maximum discharge at critical head||4,920 cfs per unit|
|Length of draft tube||59 feet|
|Total installation||364 MW|
|Average annual energy||654,701,000 kilowatt-hours|
|Generator rating||(0.9 pf)||44,444 kva|
|Generator speed||100 rpm|
|Generator voltage||13.8 kV|
|Transformer rating,||three three-phase,||each 105,000 kva|
|Transformer rating,||one three-phase,||52,500 kva|
|Transformer voltages, kV||13.2 to 115 kv|
|Location East (South Carolina) Bank, Downstream|
|Number of Bays||11|
|Number of Generator Bays||4|
|Number of Line Bays||7|
|Equipment voltage||115 kV|