Reservoir levels behind Nine Mile Dam will be fluctuating in the next few weeks as dam operators test new spillway gates, Avista said Tuesday.
The gates will allow the utility to maintain the reservoir pool at a more constant level throughout the year, according to an Avista news release.
On Sunday, Nine Mile Reservoir was raised to full pool. Over the test period it will be gradually lowered and raised as much as 10 feet several times.
Avista advises the public to stay out of the section of the Spokane River above Nine Mile Dam to Plese Flats during this testing period.
The reservoir level should be back to full pool by the first part of December.