Palisades Dam Security Enhancement Project Final Environmental Assessment and FONSI

The Bureau of Reclamation has selected the construction of a roadway bridge downstream of Palisades Dam as the preferred alternative outlined in a Finding of No Significant Impact (FONSI) and Final Environmental Assessment (EA) for the Palisades Dam Security Enhancement Project. Palisades Dam is located on the Snake River about 70 miles east of Idaho Falls, Idaho.

Reclamation is issuing a FONSI describing the construction of a new bridge as the preferred action alternative after careful review of public and agency comments, and considering all of the potential security and environmental impacts that were in the Draft EA. Reclamation has also determined that an Environmental Impact Statement is not required.

Reclamation’s Snake River Area Office distributed the Draft EA for public review and comment on January 26, 2011, the comment period closed February 25, 2011, with 12 comments received.

The Draft EA addressed alternatives to correct security vulnerabilities related to motor vehicles traveling across the top of the dam and analyzed the impacts of five alternatives including a no action alternative.

Construction for the bridge is estimated to cost about $3.7 million and take about 8 months to complete, beginning in October 2011 through May 2012. Construction on the piers and bridge deck will take place between November 2011 and March 2012, when boater use is at its lowest.

Palisades Dam was constructed by Reclamation in 1957 as part of the Palisades Project. It is a multipurpose facility that provides irrigation, flood control, hydropower, and recreation.

Downstream Water Crossing

Downstream Water Crossing

Palisades Bridge Concept View

Palisades Bridge Concept View

03/2011 Palisades Dam Security Enhancement Project Final EA and FONSI PDF 5.4 mb
01/2011 Palisades Dam Security Enhancement Project Draft Environmental Assessment PDF 4.3 mb
More information about security at dams in Idaho >>


Robert “Hap” Boyer
(208) 678-0461 ext. 15

Bureau of Reclamation
470 22nd Street
Heyburn, ID 83336

Last Updated: 6/7/16