New assessment, recovery options for Nemadji River watershed
Every spring as the snow melts, every summer after heavy rains, the Nemadji River spews red clay and other muck into Lake Superior. In fact, it's the worst offender among all streams in the region. The plume of muck into Lake Superior was so bad ...
Every spring as the snow melts, every summer after heavy rains, the Nemadji River spews red clay and other muck into Lake Superior.
In fact, it's the worst offender among all streams in the region. The plume of muck into Lake Superior was so bad after the June 2012 flood, it could be clearly seen in photos taken from space.
On Tuesday, the Minnesota Pollution Control Agency released its reports on water quality in the Nemadji River watershed and what can be done to stop the flow of sediment and other pollutants. The state will take public comments on the reports through March 15.
It's the latest in a series of efforts dating back decades to stop the Nemadji's tainted flow.
"I think the difference this time is that the reports take a broader look at the entire watershed, both the good and the bad. We found some still quality streams, like the South Fork, where it's not a matter of restoration but protection to keep what we have,'' said Karen Evans, project manager for the PCA.
The new effort also looks at nutrients and biological health, not just sediment.
The report calls for restoration efforts on 12 of the 22 streams and two of eight lakes in the watershed. Those 14 waterways don't meet water quality standards for sediment load, bacteria, nutrient levels - too high - and for fish and invertebrate populations that are too low.
The "impaired'' or polluted waterways include Lac La Belle and Net Lake, and Deer, Elim, Mud and Skunk Creeks, all among the 40 percent of Minnesota lakes and streams officially listed as "impaired."
The PCA, Nemadji River Watershed stakeholders group and the Carlton County Soil and Water Conservation District are proposing several major steps to improve the water quality, including assessing culverts and septic systems to make sure they aren't contributing pollution; stopping livestock access to streams; improved buffers around streams and lakes to help keep pollution out; better forest management to prevent erosion and limit runoff; and restoring natural stream channels "where appropriate."
"You can slow the flow of water in the upland areas, with tree planting, wetlands, maybe conservation easements,'' Evans said. "And you can also do it in the stream bed itself by strong meandering or restoring the floodplain level so the water doesn't just rush through the stream channel."
The reports also suggest moving to "low impact development'' in the watershed to decrease the impact of more people living and working in the area. Carlton County foresters, for example, already are working to limit logging on sensitive county-managed land to avoid disturbing the soil, Evans said.
The Nemadji's often ruddy-brown plume runs into Lake Superior through the Superior Entry. The Nemadji drains a huge, 433-square-mile area straddling the Minnesota-Wisconsin border south of Duluth-Superior, all the way into Pine County, including most of Carlton County. The rolling hills and mix of farms and forests that make this area so appealing are the same qualities that contribute to the problem. The clay and sand, left by glacial Lake Duluth centuries ago, make a fragile base for an ecosystem much more prone to erosion than the nearby St. Louis River, which runs through more rocky and boggy country.
Similar recovery efforts are underway in the Wisconsin portions of the Nemadji watershed as it runs through Douglas County, including wetland restoration to slow water flow.
Water from rain and melting snow that was once absorbed by thick forests and wetlands along the Nemadji and its tributaries now flows quickly off fields, down roads and ditches and into streams overwhelmed by mini-floods.
The U.S. Geological Survey reported years ago that the Nemadji has the highest sediment load of any Lake Superior tributary in Minnesota or Wisconsin - more than 100,000 tons each year. That's like backing up 21 dump trucks and unloading clay into the lake every day, all year.
It wasn't always like this. In the 1800s, the Nemadji and its tributaries ran much slower and clearer. Past reports have credited the problem to intensive logging, farming, road construction and development.
"The models show that the projects that have occurred so far appears to have made a difference, that it's improved some,'' Evans said, adding that it may be impossible to return the Nemadji to pristine status.
The first report released Tuesday discusses the "Total Maximum Daily Load," the amount of pollutants that water bodies can accept and still meet water quality standards. It also identifies pollution sources and proposes ways to bring water quality back to acceptable levels.
The second report, known as a Watershed Restoration and Protection Strategy, summarizes efforts to monitor and improve water quality and identifies future strategies for restoring, improving and protecting the watershed's water quality.
These draft Nemadji watershed reports are part of the state's approach to take a "holistic"' assessment of an entire watershed and not just individual lakes and streams.
The reports are available on the PCA's Nemadji River Watershed webpage at bit.ly/2keRZWZ or at the MPCA's St. Paul office. Comments should be submitted by March 15 to: Karen Evens, MPCA, 525 Lake Avenue South, Suite 400, Duluth, MN 55802, email@example.com . Comments must specify the applicable report, sections and actions desired, plus the reasons supporting those suggestions.