NPDES Permit for Dworshak Dam in Idaho

Below are EPA's National Pollutant Discharge Elimination System (NPDES) permit and supporting documents for the U.S. Army Corps of Engineers Dworshak Dam located on the Nez Perce Reservation near Ahsahka, Idaho.

• Permit number: ID0028586
• Effective date: April 1, 2024
• Modified: June 13, 2024
• Permit expires: March 31, 2029

• NPDES Permit, Dworshak Dam, Idaho, #ID0028586 (pdf) (437.5 KB, June 13, 2024)
  Final discharge permit including 2024 minor modification.
• Water Quality Certification for NPDES Permit, Dworshak Dam, Idaho, #ID0028586 (pdf) (71.05 KB, September 20, 2023)
  EPA's certification that the NPDES permit complies with section 401 of the Clean Water Act and Nez Perce Tribal law.
• Response to Comments on Draft NPDES Permit, Dworshak Dam, Idaho, #ID0028586​ (pdf) (196.49 KB, September 2023)
  EPA's responses to public comments received on its September 2022 draft permit.
• NPDES Permit Fact Sheet, Dworshak Dam, Idaho, #ID0028586 (pdf) (1.18 MB, September 2022)
  Technical basis for draft permit.