Blakely Mountain Dam Powerhouse Lake Ouachita

Lake Ouachita Blakely Mountain Dam and Power Plant opened in 1955 with a capacity of 75 megawatts.

The hydropower units at the Blakely Mountain were in full commercial operation by October 1955. Over its half-century of service, Blakely Mountain Power Plant has produced over nine billion kilowatthours of energy.

The Average Annual Hydropower Revenue of Blakely Dam Operation is $11,738,000. These are the dollars that, on average, are deposited into the Treasury each year from the power and energy produced.

By federal law the hydropower plants are required to recover and pay back to the Treasury all cost associated with power production and dam maintenance.

This is done by the sale of power to publicly owned cooperatives.

In addition to the tangible benefits produced by the Blakely Dam power project, there has also been a considerable amount of greenhouse gas emissions prevented since the first unit came online in 1955. Estimates of emissions offset are seven million tons of carbon dioxide, 22 thousand tons of sulfur dioxide, and 18 thousand tons of nitrogen oxides. And in order to replace the energy generated over the years, an equivalent amount of energy would have to be generated using over 15 million barrels of oil, four million tons of coal, or 92 billion cubic feet of natural gas.

To generate hydroelectric power at Blakely, water from the power storage pool ( Lake Ouachita ) is released through the gate-controlled intake section of the dam. This water rotates the turbines in the powerhouse, and discharges through the draft tubes into Lake Hamilton. The spinning turbines are connected to generators that actually produce the electricity. The power generated is increased in voltage by a transformer for transmission into the regional power grid for use in Arkansas, Texas, and Oklahoma.

In 2006 then Commander of the Corps’ Mississippi Valley Division Brig. Gen. Robert Crear, along with U.S. Congressman Mike Ross of Arkansas; Carmie Henry, Vice President of Government Affairs for Arkansas Electric Cooperative Corp.; and Dallas Cooper, Assistant Administrator of Southwestern’s Office of Corporate Facilities joined together in a ceremonial burning of Blakely Mountain’s mortgage.

The powerhouse at Blakely Mountain also controls the electricity production of lake Greeson and Lake Degray dams. The third and last hydroelectric facility built in the district was the DeGray Dam and Powerplant, which began operation in 1972 with two generators and a total installed capacity of 68 megawatts.

In the Vicksburg District, the generation of hydroelectric power began in 1952 when the power plant at Narrows Dam on Lake Greeson went into operation. Initially Narrows Dam had two generators with a capacity of 17 megawatts, but a third generator added in 1969 increased the capacity to 25.5 megawatts.

Lake Ouachita, Arkansas, Water Supply Storage Reallocation Study Corps of Engineers
Vicksburg District
159th Committee Meeting
Oct. 21-22, 2009
Canon City, Colo.

Studies were completed in Apr 07 which recommended reallocation of storage in Lake Ouachita to the Mid-Arkansas Water Alliance (MAWA) for M&I water supply. The reallocation study was performed at the request of MAWA to purchase enough storage to yield 20 million gallons per day in Lake Ouachita. The proposed reallocation would raise the top of the conservation pool by 0.82 foot. In May 06, a risk assessment screening was performed for Blakely Mountain Dam as part of the Corps-wide dam safety initiative. Blakely Mountain Dam was classified as DSAC II largely due to recently discovered anomalies in the underdrain system which occurred during construction of the dam. Water reallocation by raising pool elevations is inconsistent with DSAC II dam guidance until corrective measures can be taken. Further studies directed at water reallocation from the conservation (hydropower) pool which would not involve raising pool elevations are being conducted. Studies involve preparing a new Environmental Assessment directed at conservation pool reallocation and coordination with the Hydropower Analysis Center (HAC) and the Southwestern Power Administration.
The study is scheduled to be completed in FY 10.

U.S. Representative Mike Ross Secures $7 Million in House for Blakely Mountain Dam .
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