In his column "Who manages Lake Minnetonka: state agencies" published in the March 19 issue of the Lakeshore Weekly News, Dick Osgood makes a number of assertions about lake management and the Minnehaha Creek Watershed District's work that need clarification and correction.
In an apparent effort to convince readers that dealing with runoff is not effective in improving water quality, he cites a MCWD project in Minnetrista where the district is restoring former cropland to prairie and oak savanna. Unfortunately, his portrayal of this work misses the mark on a number of levels.
The project, called the "Six Mile Marsh Prairie Restoration," is part of a much larger effort to improve the water quality throughout the entire Six Mile Marsh subwatershed, which ultimately drains to Halsted Bay. This collective work will benefit all of the lakes, streams and wetlands upstream of Halsted Bay as well as the bay itself, a foundational tenet of watershed management.
Multiple goals are associated with this project. Not only will phosphorus loading into Six Mile Marsh be reduced by 200-350 pounds per year, it will also virtually eliminate the thousands of pounds of sediment that are eroded from the site and deposited into Halsted Bay each year, which is another big contributor to its poor water quality. The district's acquisition of 209 acres of farmland (not 113 acres as cited) also will restore native plant communities and wetlands, improve groundwater recharge, and provide much-needed habitat for a variety of prairie species, migratory birds, waterfowl, amphibians and mammals. Pheasant populations may also benefit.
Because of these factors, the U.S. Fish and Wildlife Service has partnered with the MCWD on this project. According to USFWS Wildlife Biologist Mike Malling, "More than 30 species of birds will be positively impacted through this initiative and the USFWS looks forward to working with MCWD and its partners on this project to improve critical habitat."
Another point of clarification - the $30 million that Osgood cites is the amount projected to be needed to address nutrient loading and stormwater runoff within the entire 27 square mile Six Mile subwatershed, not just Halsted Bay.
Several lakes upstream of Halsted Bay are listed on the state's list of impaired waters and the Minnesota Pollution Control Agency is requiring action at the local level to clean them up. In response MCWD is actively working with its local communities and lake associations to protect and restore the lakes and streams within the Six Mile subwatershed (Pierson, Marsh, Wasserman, East/West Auburn, Steiger, Lunsten, Parley, Mud and Six Mile Marsh), while improving overall ecological integrity.
This subwatershed approach is based on sound science and is one of the first concepts taught to students learning about natural resource management. According to The Practice of Watershed Protection, by Thomas R. Schueler and Heather K. Holland, streams and their watersheds have gotten little attention compared to the larger lakes, rivers and estuaries to which they drain. The authors go on to say, "Collectively, however, these small watersheds provide critical natural services that sustain or enrich our daily lives." These services - including filtering drinking water, providing flood control, wildlife habitat and recreational opportunities - are maximized when their land area is maintained in a natural condition, according to Schueler and Holland.
Osgood also claims he is not aware of a single case in the nation where mitigating urban or agricultural runoff has resulted in restoring a nutrient-impaired lake. In fact, there are at least three examples of projects that have accomplished this goal right here in the Twin Cities, two of them in the Minnehaha Creek Watershed District.
In the MCWD, Lake of the Isles and Brownie Lake were both taken off the state's impaired waters list because of combined action by the district, city partners and the Minneapolis Park and Recreation Board to reduce runoff.
In the case of Brownie Lake, stormwater management practices funded in part by the MCWD at the West End development in St. Louis Park reduced the amount of phosphorus and stormwater runoff flowing to Brownie Lake. As a result, Brownie Lake was taken off the impaired waters list and partnering with the developer saved district taxpayers over $400,000.
It was also recently announced that Schmidt Lake in the Shingle Creek Watershed District is proposed to be delisted because of watershed management combined with internal loading, the exact approach the MCWD is taking for Halsted Bay.
These are not the only examples of how reducing runoff can help restore nutrient-impaired lakes. MPCA Project Manager Chris Zadak said, "Several lakes across the metro area are trending towards being delisted or otherwise improving because of aggressive management at a watershed/landscape level."
While acknowledging these successes, the MCWD recognizes that water quality is not just about nutrients coming off the landscape; water quality is also impacted by internal loading caused by nutrients already in the lake.
In the case of Halsted Bay, the MCWD's Comprehensive Water Management Plan specifically acknowledges a reduction in loading from upstream and management of internal loads will be required to improve water quality. The plan specifically states, "The most effective option for improving Halsted Bay is likely a combination of alum injection treatment at the discharge into the bay and internal load management of the bay itself."
Lakes and streams do not respond immediately to efforts to restore impairments that are the result of hundreds of years of landscape activities. To quote the MPCA's Chris Zadak, the "period of monitoring and implementation for impaired waters is short compared to the time we have been impacting lakes."
The MCWD will continue to work diligently with its partners to improve the water quality across the entire 181 square miles of the watershed district, including Halsted Bay and the subwatershed that drains into it, regardless of the time it takes to achieve this important goal. But it will do so using sound science, time-tested and cost effective techniques, and projects that benefit the ecology and improve the quality of life for people and other living things in the watershed.
Jim Calkins is president of the Minnehaha Creek Watershed District board of managers.