During the summer of 2009, monitoring crews completed the second of a ten-year effort to assess the condition of rivers, streams, and lakes in Minnesota. This work is funded by the Clean Water Legacy Act passed by the Legislature in 2006.
The majority of the monitoring activities focus on watersheds. There are 81 major watersheds in Minnesota. Each watershed is comprised of a network of largely interconnected streams, lakes, and wetlands. The intent of this monitoring effort is to develop a complete picture of the conditions of the various waterbody types within each watershed.
The monitoring in rivers and streams is carried out by two biological monitoring units. The MPCA biological monitoring staff is divided into a north team located in Brainerd and a south team in St. Paul. This summer, the north team worked in the watersheds of the St. Louis River, Buffalo River, and the Elk/Clearwater/Rice Rivers. The south team worked in the watersheds of the southern St. Croix, Cedar, and Chippewa Rivers. In addition to the MPCA crews, several local partners assist with stream monitoring, funded by MPCA grants.
The stream monitoring is designed to measure and evaluate the condition of rivers and streams by studying the biology including fish, aquatic invertebrates, and plant life, as well as habitat and water chemistry. Examples of aquatic invertebrates include insect larvae, crayfish, snails, small clams, worms, and leeches. Stream water chemistry is monitored to provide information about the quality of the water in which these fish and insects are living.
Lake monitoring crews sampled more than 50 lakes in each watershed. The lake monitoring teams focused on nutrient concentrations and other water chemistry parameters to assess lakes for their ability to support recreational uses.
There are certain expectations for what the biology and water chemistry should look like at a given sampling location. If actual samples differ significantly from those expectations, the sampling location could be considered impaired. If that happens, the MPCA looks more closely at what could be causing impairments and finds ways to correct the problem.
In addition to these watershed activities, the south biological monitoring team sampled 65 wetlands around the state as part of a multi-year, interagency effort to better understand wetland water quality and quantity in Minnesota. Other MPCA monitoring teams track water quality trends at major rivers, and work with the Department of Natural Resources to establish permanent flow and water quality sampling stations at the outlets of most major watersheds in Minnesota.
The MPCA also relies on a large contingent of volunteers and local partners statewide to collect water quality data on lakes and streams, which is used to assess water quality.