The Spokane River provides us all with clean and affordable electricity, and much more, including a home for fish, habitat for wildlife and opportunities for recreation. We are committed to helping protect and enhance the health of the river. One way we work toward that end is in our fishery efforts in the river and nearby lakes.
Avista’s Long Lake Dam creates the reservoir known as Lake Spokane, a great place to swim, boat, fish and live. As part of our operations on Lake Spokane, we monitor the water, particularly the fluctuation of oxygen and temperature. This helps us better understand conditions important to the fish who live in the lake.
Lake Spokane is managed to promote both warm water and cold-water fish, and to support sports fishing and native fish restoration. “Cold water fish, such as trout, are looking for water with cooler temperatures and high oxygen levels. That’s the sweet spot,” said Monica Ott, environmental scientist with Avista. “To better understand their preferred areas we are exploring temperature and oxygen levels available in the shallower areas of the lake.”
Avista has monitored Lake Spokane for more than 10 years, in partnership with the Washington Department of Ecology. This year we implemented a new technique using automated recorders affixed to buoys at three different locations on the lake. This allows us to get readings of temperature and oxygen every 15 minutes, at varying depths.
Staff visit each buoy every other week throughout the summer and download the data, which we share with the Department of Ecology. Additionally, staff visit other baseline locations on the lake, from which we have recorded data for the past decade and capture manual readings. At those sites, Monica measures temperature, pH, conductivity and oxygen from the bottom of the lake to the surface.
“It gives us a vertical profile of the water column and allows us to compare data so that its relevant to our past data.”
In 2012, Avista initiated a 10-year plan to improve total dissolved oxygen in Lake Spokane. The data Monica collects helps us better understand the number of factors that contribute to the lake’s health.
One effort Avista has undertaken with the Washington Department of Fish and Wildlife to improve the lakes health is carp removal. Carp, an invasive species, often uproot and disturb vegetation, ultimately reducing oxygen levels in the lake. By removing carp, there are fewer invasive species competing with native species for the same habitat. In addition, excess phosphorus is removed from the watershed, which improve oxygen levels.
Another mitigation effort is a bulkhead removal program. Avista works with agency stakeholders and landowners to restore lakefront property to a more natural shoreline, to reduce erosion, add shoreline habitat and improve water quality on the lake.
Education is also key. “We want to let people know what water quality means, how dissolved oxygen gets improved and what they can do to make a difference,” said Monica. Partnering with state agencies and local homeowners, Avista is one of many stakeholders who have an impact on the lake. “We’re all in this together,” she said.