The enjoyment of the scenic vistas and exceptional fishing on the Poplar River in Lutsen may be priceless—but the work to remove the river from the Minnesota Pollution Control Agency (MPCA) impaired waters list carries a huge price tag. Reports presented to attendees at a recent Poplar River Management Board (PRMB) meeting detailed the work that has been done—and the money spent—to date to reduce erosion and sediment, as well as future plans for further improvement.
The Poplar River was named to the MPCA impaired waters list in 2004 because of high turbidity levels. In response to that designation, the Poplar River Management Board (PRMB) was formed in 2005 and since then it has worked with the Cook County Soil & Water Conservation District (SWCD) to find funding to study the causes of the turbidity and to find ways to reduce turbidity. The data collected from those studies was used to apply for a Clean Water Legacy grant of $350,000.
According to a Cook County Soil & Water Conservation District (SWCD) report, those 2007 – 2009 funds were “leveraged” by another $64,758 from area landowners; $3,705 from Cook County; $10,519 from Cook County Soil & Water Conservation District (SWCD); $9,409 from the Minnesota Conservation Corps and additional federal funding of $2,240, for a total project cost of $440,632.
That funding is the first phase of a multi-layered plan to improve the Poplar River. The $440,632 paid for stabilization of an area of erosion called the Mega Slump; replacement of two failing culverts in the ravine between Moose and Mystery Mountains; installing rip-rap and reseeding on Ullr Mountain; and “gullying” at an irrigation pond outlet at Superior National at Lutsen Golf Course.
Another $1 million grant has been applied for to work toward the goal of removing the Poplar River from the impaired waters list. Cindy Gentz, Cook County water plan coordinator, said the grant to EPA under its Great Lakes Restoration Iniative was submitted in January 2010. “We want to keep this going,” said Gentz, “the Total Maximum Daily Load [TMDL] study is not yet complete. But the landowners are taking steps to improve water quality now, rather than wait. We want to keep this going.”
In the grant application, Gentz wrote that the “Watershed Best Management practices, planning, and implementation” proposed, along with the work that has already been done, will result in a 48% reduction in suspended sediment in the river. A “secondary outcome” of sediment reduction will be a reduction of nutrients, metals, organics and other pollutants that are eroded directly from upland sources.
According to Gentz, four projects have been engineered, have landowner support and are “shovel ready.”
Gentz also wrote that monitoring of the Poplar River for turbidity and flow is continuous through state agency-maintained automated monitoring devices in the river. Thismonitoring will track progress as each best management practice is put in place. Gentz said that if these problem areas are addressed now, they will not only cease to contribute harmful levels of sediment to the river, but they will also be prevented from becoming catastrophic problems in the future.
At press time, SWCD, PRMB, and the other partners are still waiting to hear if the grant funding will be received. “It’s hurry up and wait at this point,” said Gentz.
ThePoplar River sediment reduction proposals will be discussed further at the next meeting of the Poplar River Management Board on April 12 at noon at Caribou Highlands Resort in Lutsen.
Summaries of the four projects that would be completed if the $1 million grant is received:
Ullr Gully tightline:
A 10’ x 40’ x 350’ gully on Ullr Mountain, running between the Ski Hill Road and the Poplar River, was created many years ago as the result of ski hill development, concentrated flows created by culverts on County Road 5, and the natural topography. The flows are too large, and the slopes too steep, for a conventional rock-lined conveyance. Engineers have recommended a “tightline” that would collect storm water in a 130,000 gallon collection basin above the gully, send it in a pipe to a 10,000 gallon energy-dissipating vault adjacent to the river, from which flows would discharge to the river at low velocity.
Roads:
Although square footage of roads at the ski hill has been reduced by about 50% by abandoning and re-vegetating unused roads, more work is needed to reduce sediment delivery to the river. Spread among the four mountains, there are six roads that have been identified as most critical to repair. Road surface sediment will be addressed by surfacing with gravel and by setting road width to the minimum width consistent with acceptable standards for vehicle safety. The movement of water off the road surface will be addressed by armoring ditches and building rock check dams. Coir logs will be installed to flatten cut bank slopes.
Flow Paths:
A report by Dr. John Nieber of the University of MN identified critical “flow paths” as sources of sediment in the river. The grant money would address the “Caribou Highlands Flow Path,” a long, thin strip of land that separates Caribou Highlands Resort and the Poplar River. The strip includes a ski run and two roads. The plan is to re-surface 5,500’ of roadway with Mn/DOT Class 6 aggregate and to construct storm water control structures to improve the delivery of water through this area to the river. The other concern to be addressed is the “Lower Mystery Mountain Flow Path,” an area immediately adjacent to the river. This area includes several ski runs, roads, and has very fine clay soil.
Stream Bank Trail Restoration:
The mouth of the Poplar River near Lutsen Resort is a popular recreation spot. Access is provided by mountain trails, which need improvement to eliminate erosion, sloughing, and to provide safe access to the river and upland points of entry. Portions of the trail on the west bank of the river are closed as they are unimproved and are not safe. The plan is to use best management practices to reduce sediment and provide beach and river access.
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