As winter approaches, picturesque lakefronts can transform into frozen wonderlands. But the beauty of ice can turn ugly when ice jams form.
Ice jams at the southern outlet of Osoyoos Lake in Washington state appear to be occurring more frequently and have negative consequences upstream for lake level management and downstream for river discharge.
That’s why the International Osoyoos Lake Board of Control has contracted with the US Geological Survey to investigate ice jams on Osoyoos Lake and in the Okanogan River between the outlet of the lake and Zosel Dam.
“We hope to understand these ice jams better, and then the scientific information gathered can help us decide if there are mitigation efforts that can be done to help the situation,” said Andrew Long, a USGS hydrologist and the board’s US secretary.
The USGS project is being led by Nicholas Sutfin and Stephen Breen with the USGS Washington Water Science Center in Tacoma. Long also works there and serves on the Osoyoos board with Canadian Secretary Martin Suchy, a water resources scientist with Environment and Climate Change Canada.
The ice jam project is funded by the International Joint Commission’s International Watersheds Initiative.
The study objectives are three-fold: to assess environmental conditions that contribute to the formation and breakup of ice jams, determine the historical frequency of ice jams and develop an empirical model to predict ice jam formation based on environmental conditions.
Osoyoos Lake spans the international border between Washington state and the province of British Columbia. The Osoyoos board oversees the operation of Zosel Dam by the Washington Department of Ecology to manage water levels in the lake.
Ice jams occur at air temperatures below freezing, which isn’t a surprise. But wind or warm water temperatures can prevent the formation of a solid ice sheet. Winds from the north then transport ice to the southern outlet of the lake and block the flow of water.
By studying records from satellites such as Sentinel-2 and Landsat-8, researchers are examining the history of ice jams to correlate the jams with environmental conditions like air temperature, wind speed and direction.
Osoyoos Lake as seen February 19, 2020, from Sentinel-2
Besides concerns about ice jams contributing to increased lake levels and exceeding levels established by IJC Orders, decreased outflows from Osoyoos can harm incubating salmon and their eggs.
USGS researchers hope to complete the ice jam project by March 2024. A final report on the phenomena can be used by the board to evaluate if options for engineering solutions to prevent ice jams should be further considered in the future.
Osoyoos Lake as seen February 1, 2021, from Landsat-8
Jeff Kart is executive editor of the Shared Waters IJC newsletter and a contractor to the US Section of the International Joint Commission in Washington, D.C.