The vast majority of the Winnebago River watershed is cropland (73%). The other major land uses include pasture or hayland (11%), developed for urban use (9%), water (4%), and woodland and natural areas (3%).
Bear Lake is a large and shallow lake, encompassing 1,560 acres at the ordinary high water level with a mean depth of 2.1 feet and maximum depth of 4 feet. In 1972, the Minnesota Department of Natural Resources designated Bear Lake as a Wildlife Management Lake. It suffers from a large population of invasive rough fish, and high levels of suspended sediments, algae, and total phosphorus. All major measures of lake water quality point to a hypereutrophic (very highly productive for algae) lake condition. Total phosphorus averages about 229 parts per billion (ppb), whereas a healthy shallow lake in this region should be around 90 ppb. Chlorophyll, a measurement of algae, averages about 91 ppb, whereas a healthy lake should be about 30 ppb. Water clarity measures only about 0.4 meters during spring and summer, compared to 0.7 m for a healthy lake.
State Line Lake, located in the town of Emmons on the Iowa border, is a 445-acre lake. Water clarity during the spring and summer averages about 0.2 to 0.3 meters. There is limited water quality data available for this lake, which is surrounded by housing, farmland, and Gateway Park in Emmons.
What's being done
Monitoring and assessment
Monitoring activities in the Winnebago watershed increased in rigor and intensity during 2015, focused on biological monitoring (fish and macroinvertebrates) as a means of assessing stream health. The MPCA will use the monitoring data to determine the health of streams and lakes in this watershed.
- Winnebago River Watershed Stressor Identification Report (wq-ws5-07080203a)
- Winnebago River and Upper Wapsipinicon River Watersheds Monitoring and Assessment Report (wq-ws3-07080203b)
Strategy development for restoration and protection
In 2010, the Minnesota DNR started a lake and watershed improvement effort for the Steward Creek and Bear Lake subwatershed. The total watershed area is 24,901 acres, and also includes the Freeborn County Ditch 79 subwatershed. DNR staff worked across traditional divisional boundaries and with local government to provide information on the lake and watershed, and to help guide a future direction for improved lake conditions. The DNR developed a publication called “The Bear Lake Watershed Story, a guide to water quality and watershed health” and provided it at meetings. This effort is ongoing among the DNR, local governmental units, and watershed landowners.