Hawk Creek cleaning is making an impact
WILLMAR -- Efforts to improve water quality in Hawk Creek are showing results, but a solution to one of the more troubling of the problems remains elusive.
Ten years of data show a steady trend toward decreasing amounts of sediment and phosphorus in Hawk Creek and Beaver Creek, two important tributaries to the Minnesota River, according to Cory Netland, director of the Hawk Creek Watershed Project.
Netland spoke at the watershed project's annual meeting Wednesday in Willmar.
"We've definitely made a difference over the last 10 years,'' Netland said.
Yet while phosphorus and sediment loads have decreased, the amount of nitrogen being carried by the waterways continued to slowly increase through the period. Nitrogen is the nutrient carried to the Gulf of Mexico and blamed for hypoxia or the growing "dead zone.'' The nutrient causes massive algae blooms that die. Bacteria that devour the algae consume the oxygen needed by sea life.
"We're not seeing a good trend,'' said Netland in reference to nitrogen levels in the waterways. He called the issue the "800-pound gorilla in the room'' due to national concern about the dead zone.
Netland said there is otherwise good evidence to show that the implementation of best management practices and perennial cover provided by conservation lands are serving to reduce phosphorus and sediment loads. The past decade has shown steady progress, with some exceptions. Ditch clean-out work in 2009 probably led to the increased sediment load recorded that year, he said.
The phosphorus load in Hawk Creek may show an even greater decrease in the coming years. Willmar's new wastewater treatment plant will reduce the contribution of phosphorus to Hawk Creek by the municipality.
The Hawk Creek Watershed Project is also focusing its cleanup efforts on some of its headwater lakes, including Long Lake near Willmar, Ringo, East Twin and West Twin, as well as West Solomon and St. John's lakes near Pennock.
Monitoring results about to be published show that Long and Ringo lakes are impaired due to excessive nutrient levels, Netland said.
West Solomon and St. John's lakes are overburdened by phosphorus amounts that are well above standards for the waters as well, he reported.
Netland also told audience members that 2010 was one for the record books in terms of water flows in Hawk Creek. The waterway saw flow levels in spring top 6,000 cubic feet per second, a level that caused significant damage to banks in lower portions of the channel.
The waterway also experienced several large "spikes'' or influxes of water from rain events through the summer and the fall. By the end of the year the waterway had handled an estimated 101 billion gallons of water, or three times the flow of any other year in the past decade.
All that water would fill Lac qui Parle Lake three times over, he said.