Cradled in Virginia's rugged Allegheny Mountains, the world's
most powerful pumped storage generating station quietly balances the electricity
needs of millions of homes and businesses across six states.
The Bath County Pumped Storage Station, which went into operation
in 1985, is jointly owned by Dominion and the operating companies of the Allegheny
Power System, and managed by Dominion Generation. This mammoth station was cited
as one of the nation's most outstanding 1985 engineering achievements. The earth
and rock fill moved to construct the dams and other project facilities, if piled
up, would create a mountain 1,000 feet (305 meters) high. Enough concrete was
poured to build 200 miles (322 kilometers) of interstate highway.
The station consists
of two large reservoirs — one 1,262 feet (385 meters) higher than the
other, a massive power house and the huge tunnels that connect them. When
demand is low, water is pumped from the lower reservoir to the upper one.
When demand is high, valves permit water to run through the
tunnels to the lower reservoir at a rate as high as 14.5 million gallons (915
cubic meters/second) per minute, turning six 350-megawatt turbine generators.
The water level in the 265-acre upper reservoir can fluctuate as much as 60
feet when the unit is operated.
The Bath County Pumped Storage Station is nearly surrounded
by the George Washington National Forest and was built in cooperation with the
U.S. Forest Service. Occupying a relatively small amount of land, it has had
minimal adverse effect on the environment. Flows to both streams, Back Creek
and Little Back Creek, are supplemented by storage from the station reservoirs.
This significantly improves stream flow during periods of drought and enhances
the environment for fish and other aquatic life.
The extreme fluctuations in water levels in the two reservoirs
make them unsuitable for recreation. However, a separate 325-acre (1.32 sq.
kilometers) public recreation area containing two lakes is located just downstream
from the lower dam. The area has facilities for fishing, non-power boating,
picnicking, swimming, hiking and camping. The recreation area is open on a seasonal
basis only.
Brief Facts
Net Generating Capacity: 2,100
megawatts
License Issued: January, 1977
Commercial Operation: December,
1985
Cost: $1.7 billion (1985)
Owners:
Dominion (60%), Allegheny Power System (40%)
Lower Reservoir:
Dam:
135 feet high (41 meters)
2,400 feet long (732 meters)
Contains 4 million cubic yards (3.1 million cubic meters) of earth and rock
fill
Reservoir:
555 surface acres (2.25 sq. kilometers)
Water level fluctuates 60 feet (18 meters) during operation
Upper Reservoir:
Dam:
460 feet high (140 meters)
2,200 feet long (671 meters)
Contains 18 million cubic yards (13.8 million cubic meters) of earth and rock
fill
Reservoir:
265 surface acres (1.07 sq. kilometers)
Water level fluctuates 105 feet (32 meters) during operation
Water Flow:
Pumping:
11 million gallons (694 cubic meters/second) per minute
Generating:
14.5 million gallons (915 cubic meters/second) per minute
Turbine Generators:
Six Francis-type 350-megawatt units manufactured by Allis Chalmers
Maximum Pumping Power (per unit):
563,400 horsepower (420,127 kilowatts)
