Minidoka Dam Spillway Replacement Environmental Impact Statement

The Bureau of Reclamation has issued a Record of Decision (ROD) to select and implement the preferred alternative to replace the spillway and headworks related to the Minidoka Dam Spillway Replacement Project.

he Final Environmental Impact Statement (EIS) outlines and evaluates alternatives considered to prevent structural failure of the existing spillway and headworks at Minidoka Dam, located on the Snake River east of Rupert, Idaho.

Three alternatives were considered in the Final EIS:

  • Alternative A-No Action, as required under the National Environmental Policy Act
  • Alternative B-Spillway and Headworks Replacement (Preferred Alternative)
  • Alternative C-Spillway Replacement.

he action alternatives differed only in the replacement of the canal headworks.

The ROD describes the Preferred Alternative which includes the designation of Special Use Areas, the reasons for selecting this alternative, and the environmental commitments. The Preferred Alternative was identified as the most efficient and environmentally-sound option for replacing the spillway.

09/2010 Record of Decision PDF 288 kb
08/2010 Final Environmental Impact Statement for the Minidoka Dam Spillway Replacement Project (without appendices) PDF 8.17 mb
08/2010 Appendices for Final EIS PDF 18.42 mb
12/2009 Minidoka Dam Spillway Replacement Draft Environmental Impact Statement (without appendices) PDF 8.32 mb
12/2009 Draft EIS: Appendices PDF 14.2 mb
12/2009 Transmittal Letter for Draft EIS PDF 29 kb
08/2009 Scoping Summary Report PDF 7.41 mb
12/2008 National Environmental Policy Act Process PDF 3.15 mb
11/2008 Comment Form PDF 30 kb


Michael Hilliard
(208) 678-0461

Bureau of Reclamation
Upper Snake Field Office
470 22nd Street
Heyburn, Idaho 83336

Last Updated: 8/16/21