Williamson/Wood River Drainage Gravel Placement FY2014

The Klamath Tribes, through collaboration with ODFW and USFWS will coordinate the addition of spawning gravel by conveyored aggregate delivery (CAD) truck to numerous locations in the Williamson, Sprague, and Wood River drainages. The CAD truck delivers spawning gravel to the river or stream by propelling the gravel from the distal end of a rubberized belt at a targeted location in a waterbody at a rate of 6 cubic yards per hour. In areas not accessible by CAD truck, the Klamath Tribes and ODFW will use a contractor with a barge and a dump truck bed. The barge has performed well on past placement in the Williamson River near Kirk Springs, and will have utility in this project. Spawning gravel will be placed specifically to benefit various life history types of Chinook Salmon (Oncorhynchus tshawytscha), Steelhead Trout (Oncorhynchus mykiss mykiss) and adfluvial Redband Trout (Oncorhynchus mykiss newberryi). Gravel has been purchased and will be placed by ODFW in August and September of 2017.

There have been numerous studies estimating spawning gravel quantity and quality in the Upper Klamath Basin. These studies suggest that spawning habitat is a limiting factor for Chinook Salmon, Steelhead Trout, and adfluvial Redband Trout. Gravel additions in appropriate areas have been used immediately by adfluvial Redband Trout, and a reasonable presumption could be made that larger phenologies of salmonids will use similar sized gravel. Augmented spawning gravel sites have shown high usage rates in almost all areas. Since 2010, numbers of spawning Redband Trout have increased in Spring Creek where extensive placement of spawning gravel has occurred. Spawning gravel also can increase macroinvertebrate abundance, provide cover for salmonid alevin and fry, and increase incubation and emergence success compared to existing poor quality substrate.