This funding project will complete the removal of three fish barriers located on the Wilson Banner Ranch on the Alpowa Creek. It is located less than a mile from the Snake River. The Alpowa Creek contains limited numbers of Steelhead and other native fish species. In order to irrigate their orchards and truck farm, block dams are constructed on a yearly basis. These dams completely block the creek during the irrigation season and severely restrict migration during other times of the year. These barrier problems have been addressed through two other grants to correct the problem. Due to the over run in construction cost of an irrigation inlet structure and delivery system, additional funding is being sought to complete the system. The entire project will be complete when a collection box between the in-stream inlet and irrigation delivery line and the moving of the irrigation pumps is complete. These concrete block dams are shown during the non-irrigation time period. When the dams are constructed, a felt layer is installed over the blocks to restrict leakage between the blocks and give the water enough height above the intake pipe to eliminate during whirlpools and pump cavitation. As the picture below shows, the height of these dams is great enough during the irrigation season to completely eliminate fish migration. One more dam is constructed similar to this one to divert water into an irrigation canal that supplies another irrigation pump.
