Report: Clean up Sauk River Chain of Lakes

RICHMOND – The Sauk River Chain of Lakes is considered one of Minnesota's success stories, with dramatic improvement in water quality in the past 30 years.

But a new report says the amount of phosphorus causing nuisance algae blooms in the Horseshoe chain needs to be cut by as much as 50 percent in some lakes to meet water quality standards.

"It's come a long ways, but it still has a ways to go," said Greg Van Eeckhout, environmental specialist with the Minnesota Pollution Control Agency.

The study from the MPCA, called a Total Maximum Daily Load report, says phosphorus levels need to be reduced by 30-54 percent throughout the Chain of Lakes, which is often referred to as the Horseshoe chain.

That will be a challenge, because the vast majority — 94 percent — of phosphorus in the 13 lakes comes from so-called nonpoint sources, such as runoff from farms and developed land.

Without a big polluter such as a wastewater treatment plant or factory at which to point fingers, the goal will be slowing the flow of phosphorus through mostly voluntary measures.

"That's a lot more difficult to do, and it's a slower and steadier progress," Van Eeckhout said.

The Sauk Chain is unique because it's essentially a large reservoir, created in 1856 when a dam was built on the Sauk River near Cold Spring to power a mill.

The chain is fed by the Sauk River, which drains a huge area of largely agricultural land. Most of the chain's lakes are considered impaired because of high nutrient levels. Algae blooms make the water murky at times.

The MPCA proposed new standards for the chain that would aim to reduce those nutrient levels and improve the clarity of the water. Because of the chain's unique dependence on the river, the MPCA proposed to treat it differently than it would a typical lake.

Phosphorus, which stimulates algae growth and affects recreation, is the primary focus of the TMDL report.

The report says phosphorus reductions of 74-86 percent are needed in the nearby Eden Creek lakes, including Long, North Browns, Eden and Vails. Those lakes are smaller, more sensitive and have accumulated more nutrients, Van Eeckhout said.

"They don't have as much water flushing through the system," he said.

The reduction goals aren't surprising to experts who have been working for years to protect the chain.

"It's pretty aggressive, but there's room for improvement out there," said Dennis Fuchs, Stearns County Soil and Water Conservation District administrator.

Fuchs said more work could be done with farmers to adopt conservation practices such as leaving crops on the field after harvest, planting buffer strips or grass waterways to reduce runoff and bringing animal feedlots into compliance with environmental rules.

Van Eeckhout said there's "no silver bullet" to fix the chain of lakes.

"There's nothing we can flip a switch on and change it rapidly," he said. "It didn't get this way overnight, and it will take time to improve it, too."

After a public comment period on the TMDL report, state regulators will make changes and send it to the U.S. Environmental Protection Agency for approval. After that, work will begin on a plan to implement the recommendations.

There is money available through the Clean Water Legacy Act for projects to improve water quality, Van Eeckhout said.

"The more interested local people are in actually doing something, the more quickly things get done," he said.

Learn more, give feedback

A public meeting on the Minnesota Pollution Control Agency's Total Maximum Daily Load study for the Sauk River Chain of Lakes will be at 7 p.m. Tuesday at the Rocori Senior Center, 527 Main St., Cold Spring.

A comment period will be open beginning Monday until Nov. 19. The full report will be available online at www.pca.state.mn.us/irypa38.

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Follow Kirsti Marohn on Twitter @kirstimarohn or reach her by phone at 255-8746.