|Hydrologic Unit Codes||17040216|
|Size||607 square miles (388,587 acres)||
Beneficial Uses Affected
|Salmonid spawning, cold water aquatic life, domestic water supply, primary contact recreation|
|Major Land Uses||Range, forest, agriculture, recreation|
|Date Approved by EPA||Subbasin assessment only; not subject to EPA approval|
The Birch Creek subbasin is located in east-central Idaho, along the Montana border. The nearest towns are Leadore to the north and Mud Lake to the south. Birch Creek makes no surface connection with any other streams; it is one of five central Idaho watersheds known as the “Sinks Drainages.”
2005 Subbasin Assessment
Other than Birch Creek, few other natural waterways exist in the subbasin. Birch Creek is completely diverted in the lower watershed to supply a hydroelectric project and is subsequently used for irrigation.
The § 303(d)-listed reach of Birch Creek occurs from the Reno Ditch to the “Playas.” This reach is permanently dewatered, and there is no mechanism by which restoration of the stream channel is possible or practical.
The dewatering of the natural channel renders any listing other than flow alteration meaningless; therefore, TMDLs were not established for nutrients, sediment, or habitat alteration. TMDLs are not required for water bodies impaired by pollution but not specific pollutants. The US Environmental Protection Agency considers flow alteration to be “pollution.” Therefore, a TMDL was not established for flow alteration for Birch Creek. The subbasin assessment recommended that this stream reach remain on the § 303(d) list for flow alteration only and the listings for nutrients, sediment, and habitat alteration be removed.
2005 Summary of Assessment Outcomes
|Listed Stream Segment||Birch Creek (Reno Ditch to Playas)|
|Recommendations||Do not develop TMDLs; list for flow alteration only|
|Justification||Channel is dry due to permanent diversion|