Minnesota Stories:

Lake Rebecca on the Rebound: Legacy Amendment Funds In Action

by Lauren Rosenthal, CM Intern

In the 20 years since John M. Barten joined the Three Rivers Park District (formerly known as the Hennepin County Park District), Lake Rebecca has struggled to meet its potential as an important and highly used recreational resource. In 2008, the Minnesota Pollution Control Agency designated the lake as impaired due to its phosphorus overrun and subsequent algae blooms – but Lake Rebecca was in trouble long before the MPCA intervened.

For decades, Lake Rebecca has suffered from severe water quality problems stemming from phosphorus pollution, the incursion of non-native species and massive algal blooms. But after the Lessard-Sams Outdoor Heritage Council recommended that the Lake Rebecca Water Quality Improvement Project, overseen by Barten, receive $450,000 in Legacy Amendment funding, the Three Rivers Park District swung into action and began taking steps to restore Rebecca to a healthy state.

Lake Rebecca is the state’s premiere muskie broodstock lake, which provides the Department of Natural Resources with fish for stocking other local lakes, and it is also home to a substantial bass population. Severe die-offs caused concern in the DNR and the park district itself. It was revealed that high phosphorus levels in the lake were indirectly to blame for the die-offs. As Barten explained, the drainage of water into the lake from nearby farms and through feedlots coupled with shoreline erosion led to high phosphorus levels. Curly-leaf pondweed is also a problem for Lake Rebecca. The plant crowds out native species and release phosphorus when they die. The high phosphorus is responsible for algae blooms which “make the lake look like split pea soup,” according to Barten.

“These blooms use up oxygen in the lake,” Barten said. “The large muskies in the lake die off due to the low oxygen concentration. This also leads to a bass die-off. And when the oxygen level drops too low, you lose panfish. When the fish come in contact with each other more, because oxygen is reduced, they pass along diseases. We have massive die-offs periodically.”

Panfish and bass die-offs spell trouble for local subsistence fisherman, and recreational fishermen also face difficulty navigating and fishing in Lake Rebecca. “There’s not a lot of fishing midsummer because it’s not very aesthetically attractive for lake users.” Barten said. “The curly-leaf pondweed growth is incredibly dense, and the lake has restrictions on outboards motors. But for canoes and paddleboats, the plant growth restricts their ability to navigate the lake.”

Currently, swimmers at Lake Rebecca must remain within the confines of a swimming curtain, but as Barten himself acknowledges, these protective measures are not without their pitfalls. “The curtain isolates the swimmers from the rest of the lake and from the lake environment itself,” Barten said.

Though the Lake Rebecca Water Quality Improvement Project’s goals are mostly ecological, the Three Rivers Park District is considering the benefits of their work on visitors’ ability to enjoy Lake Rebecca. “If we can take care of ecological problems, the recreational problems will also be resolved,” Barten said.

Barten said that the Legacy Amendment and the Three Rivers Park District shared a similar vision from the start. “The Clean Water and Legacy Bill to increase our environmental and water resources seemed a natural fit,” Barten said. “Improving the habitat and ecosystem of this lake is key. This is an important and highly used recreational resource.” Curly-leaf pondweed control is under way, and will be followed by alum treatments to reduce phosphorus concentrations. Barten is confident that partnerships with local landowners and shoreline stabilization efforts will go a long way in keeping phosphorus out of Lake Rebecca in the future and improving the health of her fish populations.

“We hope that the muskie and bass die-offs will end. It is going to take time for the lake to respond, and it could take a number of years for the benefits of this work to be realized,” Barten said. “We took a long time to get to the degraded state our resources are in, and it will take a number of years to get them back to a healthy state.”

But with the help of Legacy Amendment funding, Lake Rebecca is already well on the road to recovery. The Three Rivers Park District’s algae and curly-leaf pondweed eradication efforts are expected to allow increased native plant growth and the restoration of fish habitats, with native plant response expected within two years of starting work. Barten describes Lake Rebecca’s plight as “a long-term problem with a long-term solution,” and he is correct. But the Lake Rebecca Water Quality Improvement Project is a chance for the Three Rivers Park District and its many partners to undo decades of damage and turn back the clock to a time when Lake Rebecca was healthy and clean – a time we’ll be transported to within a matter of years.