Monitoring Lakes for Water Quality

By Beacon Staff

Twice a year, Whitefish Lake churns up its waters. As the lake loses its summer heat and autumn winds whip across the surface, warm waters from the top of the lake chill down toward equalizing with bottom temperatures. Whitefish Lake Institute monitors this change as it occurs in both fall and spring.

But Whitefish Lake is only one body of water that the institute monitors. This year, in a partnership with Montana Fish, Wildlife, and Parks, the institute took on monitoring the water quality of 20 lakes between Whitefish and Eureka. “A lot haven’t had any data previously collected on them,” said Mike Koopal, Executive Director of the Whitefish Lake Institute. The data collected will provide a baseline to develop a trend analysis over time.

The institute coordinated the project by providing water monitoring equipment and training volunteers. It also collates all the data reported by the volunteers, making the water quality information available to the public and sending it also to the Montana Department of Environmental Quality.

In an effort to raise funds for its educational efforts, the institute also experimented with boat and wine tours on the Lady of the Lake from the Lodge at Whitefish Lake. On the tours, Koopal and Chris Ruffatto presented a lake history lesson. “The tours have been hugely successful,” said Koopal. “We took a lot of Canadians and lake property owners out there.” The institute plans to continue the tours this next summer and may make them available to the public.

In summer, Whitefish Lake stratifies into three different density layers, which the institute monitors, sending the water samples into a Helena lab. Even though the top water layer may reach 70 degrees, the bottom always remains 39.2 degrees.

“We’re seeing changes in the lake with our readings,” said Koopal. “Dissolved oxygen readings at the bottom of lake are lower than what we would expect.” If dissolved oxygen levels reach a threshold, then the lake’s natural sink of phosphorous may increase algae blooms, decreasing the lake’s water quality.

In the meantime, the lake is busy with its biannual shift—a transformation that by winter will allow its surface to freeze.

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