New Findings Show Sediment Reduction on Poplar River
LUTSEN – The Minnesota Pollution Control Agency (MPCA) provided updated data trends on sediment in the Poplar River to the Poplar River Management Board (PRMB) in February. MPCA has estimated that total suspended solid (sediment) loads have been reduced by about 35% since 2006.
The sediment loads from 2002 to 2006 was about 1,000 tons per year, while the average load for the years 2009 through 2011 was about 660 tons per year.
"This is good news," said Tom Rider, President of the Poplar River Management Board. "We have worked since 2005 identifying the most significant sources of sediment and implementing best management practices and conservation projects. It is gratifying to see the work has achieved the desired results."
Rider also indicated that improvements in sediment reduction are expected even from projects completed in 2011 and before as they mature on the landscape, as vegetation takes hold.
The MPCA analysis suggests continued decrease in sediment loading should be expected from projects implemented in 2012 and planned for 2013.
This includes the Ullr Tightline project that was completed in November of 2012 with estimated sediment reductions of 90 tons/year.
Three projects scheduled for completion in 2013 will achieve even more benefits.
Caribou Highlands Flow Path, Lower Eagle Mountain Road project and the Mystery Mountain Flow Path are projected to reduce sediment by 80 tons/year, 75 tons/year and 30 tons/year respectively.
Over the last decade, using data from numerous scientific reports and research, PRMB, in partnership with the Cook County Soil and Water Conservation District, the MPCA and other stakeholders, identified and implemented $1.7 million in sediment reduction projects in the watershed.
"The Poplar River Management Board has been aggressive in identifying and implementing sediment reduction projects ahead of the MPCA's TMDL process," said Kerrie Berg, District Manager for the Cook County Soil and Water Conservation District. It is anticipated that the TMDL and TMDL implementation plan will both be finalized in the months to come.
"Our goal is to have the Poplar River removed from the impaired list as soon as possible," Rider added. "Even with this good news, we area taking steps to identify and implement additional sediment reduction projects in the near future."
These new efforts will continue the collaborative work with stakeholders to take the scientific work published to date, and overlay the project work completed this far to:
· Identify more precise figures on sediment contribution from ski runs at Lutsen Mountains. Current data on sediment contribution by ski runs presents a wide range of possible values and will require more work to develop a more definitive assessment. For example, the current model ignores the presence of water bars, which the latest studies demonstrate will reduce sediment production by a factor of 15. Water bars are located throughout the ski area and are the most common form of sediment-reduction BMP used in the ski industry.
· Inform sediment reduction project selection on Lutsen Mountains ski runs. Data generated from further field work and improved modeling will inform decision making and priority setting for project selection. This modeling will be used as a tool for targeting the installation of best management practices on ski runs. In high-producing areas, sediment reduction practices will be added into the model that will then calculate the reduction in sediment that can be achieved by implementing that change. From this we will create a comprehensive stormwater plan for the entire ski area.
The Poplar River Management Board was formed in 2005 by landowners adjacent to the Poplar River in response to the Impaired River designation by the MPCA in 2004. http://www.poplarriverboard.com/