Help for an impaired lake
Lake Shaokatan could be one of the first to get help from a recently-passed amendmentBy Per Peterson
A southwestern Minnesota lake could end up being one of the first bodies of water in Minnesota to benefit from funding raised by the new Constitutional amendment that increases by three-eights of 1 percent the state sales tax that will go toward wetlands and the environment, among other areas.
Lake Shaokatan, near the Minnesota-South Dakota border, has been on the state's list of impaired waters for a number of years because of high phosphorous levels which cause excessive algae growth, and an upcoming project will determine the Total Maximum Daily Load for nutrients and, eventually, the development of an implementation plan to achieve proper water quality standards.
A public comment period begins Monday.
MPCA spokesman Forrest Peterson says despite improvements made to the lake that date back to the early- to mid-1990s, more work needs to be done to reduce the runoff from farms and residential areas that has caused the high phosphorus levels in the lake. In 2002, Shaokatan was identified as impaired for excessive nutrients, resulting in excessive eutrophication, or high levels of mineral or organic nutrients.
"The lake has been impacted by nutrients for a long time - primarily phosphorous - and nutrients cause things to grow, just like fertilizer in the garden," said Peterson. "It creates algae, and that's the primary impairment there."
Lake Shaokatan is a 995-acre shallow lake in Lincoln County that has a maximum depth of 10 feet. The lake is managed for walleye, northern pike and yellow perch and is stocked with walleye fry every other year. The lake is the headwaters for the Yellow Medicine River, which drains into the Minnesota River.
Peterson said the lake has improved since implementation took place behind a clean water partnership grant in 1991 when the MPCA conducted a six-year Clean Water Partnership Diagnostic and Feasibility study and successful implementation project.
"There has been quite a reduction in phosphorous concentration in the lake during that time, but it's still not meeting the standards for this area," Peterson said. "That's why it's still on the impaired waters list."
Under the Federal Clean Water Act, states are required to submit a list of impaired waters to the U.S. Environmental Protection Agency every two years. Minnesota's 2008 list identified 1,475 impairments on 336 rivers and 510 lakes, the Minnesota Pollution Control Agency Web site said. Approximately 40 percent of water bodies assessed are found to be impaired, which is comparable with what other states are finding, the MPCA said. Only a small percentage of Minnesota's river miles and lakes have been assessed so far.
Peterson said whatever steps are taken to further improve the water quality at Shaokatan, public involvement will play a key role in defining the future of the lake.
"So much depends on the individual landowners, what kind of land uses there are, and making sure that people in the watershed have their septic systems up to grade and there are efforts made to prevent runoff from livestock operations, things like that - buffer strips to filter any runoff," said Peterson.
After public comments are submitted to the EPA for approval, work would begin on achieving the goals set for the lake - in this case, a 67-percent reduction in phosphorous in the watershed.
"The implementation plan would consist of a lot of different tools and different things to achieve the goals, and that's where the public part and the landowner involvement comes into play - to determine what needs to be done," Peterson said. "There may be some chemical treatments, but more so, we're looking at land use practices to prevent phosphorous from getting into the lake in the first place."
