Pickwick Landing Dam South Embankment Seismic Upgrade

Hardin County, Tennessee

On September 30, 2016, TVA issued a final environmental assessment (EA) and finding of no significant impact for its proposed upgrades of the south embankment of Pickwick Landing Dam to improve performance of the dam during and following a large earthquake. A seismic stability evaluation of the embankment completed in 2014 indicates that a large earthquake could result in the loss of strength in some soil layers of the embankment, leading to slope instability and the breach of the dam. TVA informed the public of this potential and installed an early warning system in 2015 and began developing a proposal to strengthen the dam’s embankment.

Upgrades would be made to both the upstream and downstream sides of the earthen embankment. Berms would be constructed along the toe of each side of the embankment and areas of extended fill would be placed in select locations. A small area of TVA land along North Carolina Landing Road below the dam would be used for construction laydown activities. Activities would not close or restrict travel on Highway 128 crossing the dam. TVA does not propose to change its operation of the reservoir during construction (i.e., lake levels would continue to follow the existing seasonal patterns).  Initial activities are planned to start in fall 2016, construction in late 2017, and end in late 2021.

The upgrades to the embankment would allow TVA to avoid risk to public health and safety and the significant economic impacts that would result from having to lower the reservoir below winter pool levels for an extended period following an emergency.

The EA describes the anticipated environmental impacts of these upgrades.  TVA issued a draft EA for public review and comment in August 2016.  The final EA addresses the comments TVA received on the draft EA.

Proposed Berms and Extended Fill Areas (Pickwick Landing Dam South Embankment)

Related Documents

Contact

For more information about the environmental review contact:

Matthew Higdon
NEPA Specialist

mshigdon@tva.gov
400 West Summit Hill Drive, WT 11D
Knoxville, TN 37902