On Dec. 28, the Federal Energy Regulatory Commission granted a November 2013 application from FFP Missouri 2 LLC for a license to construct and operate the proposed Sardis Lake Hydroelectric Project.
The project’s authorized capacity being licensed is 14.6 MW. The project will be located at the U.S. Army Corps of Engineers’ Sardis Dam on the Little Tallahatchie River, near the town of Sardis in Panola County, Mississippi.
A multi-project environmental assessment (EA) was prepared by commission staff and issued on Sept. 30, 2015, analyzing the impacts of the proposed project and alternatives to it. The U.S. Fish and Wildlife Service and the U.S. Environmental Protection Agency filed comments on the EA.
The project will be located on the Little Tallahatchie River at river mile 69, approximately 7 miles southeast of the town of Sardis, Mississippi. The Little Tallahatchie River flows in a southwesterly direction from its headwaters near Dumas, Mississippi, and enters the Panola Quitman Floodway (a flood control channel) before it joins the Tallahatchie River near Sharkey, Mississippi. The Tallahatchie River joins the Yalobusha River to form the Yazoo River, which in turn flows into the Mississippi River.
Sardis Dam is one of four dams that make up the Corps’ Yazoo Basin Headwater Project. The Headwater Project was authorized by Congress and provides flood control and benefits to recreation, fish and wildlife resources, and navigation.
The powerhouse will contain two identical vertical Kaplan turbine-generator units with a combined installed capacity of 14.6 MW. A tailrace, lined to prevent erosion and scour, will convey flows from the powerhouse to the existing outlet channel. Power will be transmitted via an 887-foot-long, buried transmission line from the powerhouse to a new substation. From the new substation, a 6,210-foot-long, 161-kV overhead transmission line will transmit power along Blackjack Road (Mississippi Route 315) to an interconnection point at an existing distribution line owned by a local utility.
The project will operate in a run-of-release mode using flows made available by the Corps. This flow would otherwise pass through the dam via the Corps’ outlet conduit into the Little Tallahatchie River. When the Corps’ flow releases are less than the minimum turbine hydraulic capacity of the project (300 cfs), the turbines will be shut down, and all flows will be released through the fish bypass outlet gate or the discharge gate directly to the outlet channel. When the Corps’ releases are between the minimum and maximum turbine hydraulic capacity, the Corps’ minimum target flow of 100 cfs will pass through the fish bypass outlet gate, and the remainder will pass through the turbines. When the Corps’ release is more than the maximum hydraulic capacity of the turbine units and the minimum flow, the discharge gate will be opened to pass the excess flow into the existing stilling basin.
The project will generate an average of 52,000 megawatt-hours (MWh) annually.