Hawley Creek Access and Flow Enhancement Lhac-01

Project Narrative

The project removed 1 diversion which was a fish passage barrier; this resulted in 1.5 cfs remaining in the stream preserving sufficient flow to 8.5 miles of stream; 1,086.67 acre-feet of water will be conserved. This water conservation will remain in place for a minimum of 20 years, per an agreement between the Lemhi Soil and Water Conservation District and the landowner. The open ditch irrigation system was retired and 3.04 miles of pipeline was buried. Water is now diverted from another existing diversion to 4 new irrigation pivots. Two flow meters were installed to measure water to the two water rights Point of Use sites. Five beaver dam analogs were constructed instream through 0.9 miles of stream. Hawley Creek, as a headwater tributary to the Lemhi River, is considered of particular importance to salmonid spawning given its ability to alter flow regimes, sediment inputs, and water temperatures in the upper Lemhi River. Historically, the Hawley Creek watershed was a major anadromous fish producer, but due to irrigation practices that dewater the stream and man-made migration barriers, Hawley Creek has been disconnected from the Lemhi River and inaccessible to Snake River spring/summer Chinook salmon (Oncorhynchus tshawytscha), Snake River Basin steelhead (Oncorhynchus mykiss), and fluvial Columbia River bull trout (Salvelinus confluentus) for over 100 years. The Federal Colombia River Power System Expert Panel for Snake River Steelhead and Chinook salmon identified the three most limiting factors to salmonid production in the project area as water quantity (35%), habitat barriers (20%), and mechanical injury (15%). This project addresses all three limiting factors.