By Kirsti Marohn

MPR News/90.1 FM

A planned solution to fix an algae-plagued central Minnesota lake is being postponed until next year.

The Minnesota Department of Natural Resources had planned to lower the water level of Little Rock Lake, north of St. Cloud, by 3 feet starting Aug. 1.

The drawdown would have lasted six weeks. The goal was to improve the lake’s water quality by encouraging native plant growth to use up excess nutrients — and to stabilize the shoreline to prevent erosion.

In an email Wednesday, the DNR said it needs to conduct a more thorough review of the drawdown project’s potential impacts to cultural and historical resources in order to satisfy federal requirements.

The Sartell hydropower dam that would have been opened downriver to allow the drawdown is under the supervision of the Federal Energy Regulatory Commission.

“Due to miscommunications, the historical-cultural review that was done did not meet strict federal requirements,” the email said.

After decades of phosphorus and nitrogen runoff, Little Rock Lake has almost no natural plant growth — and high levels of both elements, which fuel algae growth. Lake residents have been anticipating the drawdown as a chance to restore the lake’s health.

Eric Altena, DNR area fisheries supervisor, said the delay was disappointing, but only a temporary setback.

“We’ll be back next summer with everything in order and set to go for the same time frame,” Altena said.