Snake River - St. Croix Basin

Pokegama Creek in the Snake River -  St.Croix Basin watershed

The Snake River watershed is located north of the Twin Cities in the St. Croix River Basin and encompasses 1,006 square miles in five counties, including Aitkin, Kanabec, Mille Lacs, Pine, and Isanti. The northern portion of the watershed is located in what is known as the Northern Lakes and Forest ecoregion dominated by forests and wetlands. The southern portion is located in the North Central Hardwood Forest ecoregion and is a mixture of forest, grassland, pasture/ hay and cropland. The river flows southeast to its confluence with the St. Croix River in Pine County. 

This watershed supports a diverse range of aquatic species including fish and freshwater mussels, as well as a number of terrestrial threatened and endangered species. The watershed is also home to several outstanding resources such as the Mille Lacs Wildlife Management Area, the Solana State Forest, and the Rum River State Forest, which provide critical habitat for many species and support recreational activities such as hiking, fishing, camping, canoeing and wildlife viewing. Sections of the Snake River are part of the Snake River State Water Trail, one of the 35 Minnesota water trails used for paddling and camping. 

What's being done

Monitoring and assessment

Revisiting the Snake River Watershed (2017 – 2026)

The Snake River – St. Croix Basin Watershed was revisited in 2017 through the MPCA's 10-year watershed cycle approach, beginning with intensive watershed monitoring work. In the summers of 2017 and 2018 surface water quality monitoring staff sampled various surface water sites throughout the watershed. Monitoring work consisted of sampling for biological indicators representing the health of aquatic life in streams, and for chemistry parameters in lakes and streams for pollutants such as phosphorus and suspended sediment among others. During these two monitoring years, 7 lakes and 74 stream monitoring sites were visited multiple times throughout the spring, summer, and fall seasons. The monitoring data that was collected, along with data collected by our local watershed partners, was used to assess stream and lake water quality against state and federal water quality standards. Water quality trends were also analyzed through the MPCA's pollutant load monitoring network along the main stem of the Snake River to detect changes in water quality indicators since the first cycle of watershed work. This round of monitoring and assessment work confirms that the Snake River watershed is generally in good health.

First cycle of monitoring work (2007 - 2016)

The Snake River Watershed was sampled for stream biology in 2007, and served as a pilot for what would become the MPCA's "Watershed Approach" to monitoring and assessment in future years. Since then, stream chemistry and lake monitoring have been incorporated into the Watershed Approach. In addition, the assessment methods have changed since 2007. The assessments for the Snake River Watershed have been revised according to the new methods, but the report above was not rewritten to reflect these changes. As such, the assessment decisions in the report may differ from those recorded in the MPCA's databases. 

Strategy development for restoration and protection

As of 2020, 34 non-mercury impairments, or waters not meeting water quality standards for recreation or aquatic life use, exist in the Snake River Watershed—7 lakes and 27 stream reaches. Ten of these impairments are biological impairments, due to lower scores in the metric used to assess aquatic biotic integrity. The work of stressor identification staff identify the potential stressors causing these biological impairments. Current stressor ID work is underway for Mission Creek and Pokegama Creek and expected to be completed in 2021. Previous stressor ID reports are posted below.

A TMDL is the maximum amount of a pollutant a body of water can receive without violating water quality standards, and an allocation of that amount to the pollutant’s sources. The TMDL process identifies all sources of a pollutant and determines how much each source must reduce its contribution in order to meet the standard. Once a body of water is added to the Minnesota Impaired Waters List, a TMDL may be developed for it. A TMDL also assigns pollutant load allocations, or reduction targets, to the various sources that of pollutants that exist within the watershed. The TMDL process also identifies all sources of a pollutant and determines how much each source must reduce its contribution in order to meet the standard. 

In the first cycle (2007-2016), 15 TMDL studies were completed within the Snake River Watershed. The MPCA is currently working on 7 additional TMDL studies for reaches impaired for E. coli; these studies, along with an update to the current WRAPS report, are expected to be completed by 2021. 

One Watershed, One Plan

The Snake River Watershed is currently involved with the One Watershed, One Plan (1W1P) planning process and program through the Minnesota Board of Soil and Water Resources (BWSR). This formalized planning process will bring partners together across the watershed to develop a watershed based plan focused on prioritized, targeted, and measurable implementation goals. The MPCA will be involved with the Snake River (1W1P) as a member of the advisory committee, and will work with local partners by providing assistance in the plan’s development and review.