Irrigators who plan to test or observe their intake equipment along the Rock Island reservoir during the flow tests planned Saturday and Sunday afternoons are urged to take care along the shoreline and to watch for sudden changes in water level.
While every effort will be made to hold the reservoir at a specific level during the weekend flow tests, there is always the possibility that river levels and flows may fluctuate. Changes in the water level along the shoreline will be noticeable starting about an hour before the tests, which are scheduled 1-4 p.m., March 22 and 23.
Boaters need to be aware that the launch at Wenatchee Confluence State Park will be closed for the weekend starting Friday evening due to the expected changes in river flows and levels during the tests. That means there will be no public access to the Rock Island reservoir for boaters this coming weekend as the other launches on the reservoir are already closed.
River users above Rocky Reach Dam also may notice changes in river levels during the tests, though not to the extent expected on the Rock Island reservoir.
If there are any changes in the planned tests, information will be posted on the District website at chelanpud.org as well as on Facebook.com/ChelanPUD and on Twitter @ChelanPUD.
Chelan PUD is coordinating the weekend flow tests in the Rock Island reservoir to give irrigators an idea of the water line at the lowest level and flows, based on historical information, expected during the coming irrigation season. Also, during the tests PUD staff will be checking boat launches to determine what is needed to ensure recreation access and will gather measurements to plan modifications to fish ladder entrances below Rock Island Dam to make sure adult fish can safely migrate upstream past the dam.
All of the work is in response to last month’s discovery of a crack in the spillway at Grant PUD’s Wanapum Dam that required a dramatic lowering of the Columbia River behind the dam to reduce pressure on the structure. That in turn affected river levels upstream at Rock Island Dam, which is owned and operated by Chelan PUD.
More information about the flow tests and how to submit information to the PUD on impacts to irrigation intakes is available on the home page at chelanpud.org.