The Credit River has been removed from the Minnesota Pollution Control Agency’s (MPCA’s) list of impaired waters. While this may be easy to say, it’s a bit harder to say exactly why water quality has improved. The Credit River - which flows north from New Market Township through Credit River Township and the City of Savage before discharging to the Minnesota River - was originally listed as impaired due to high turbidity in 2002. Turbidity is a measure of water clarity (essentially, how clean or dirty the water may be); in the Credit River, much of this was related to the amount of sediment in the water.
This level of improvement comes as something of a surprise, particularly given the setting of the Credit River. In the southern reaches of the river the land is relatively flat, but then drops steeply through Savage once the river encounters the Minnesota River Valley bluff. In addition, there was a considerable amount of urban development in the watershed during the 1990s and early 2000s; typically, steeper rivers with urban development exhibit erosion and excess sediment. In fact, soil loss from construction sites can be many times that of other land uses.
Some of the improvement likely resulted from managing this change from rural to urban. Savage, Credit River Township, and Scott County all have programs to regulate and control construction erosion and require stormwater ponds to slow runoff and trap sediment. The transition from plowed fields to urban lawns with year-round vegetative cover also reduced soil erosion.
A number of water quality projects have also been completed. These include stream bank and stream side buffer (an area of native plants and trees) projects by residents along the river, as well as construction projects by Savage, the Scott Watershed Management Organization, and the Scott Soil and Water Conservation District. The Utica Ravine project completed by Savage in 2010, for example, reduced sediment delivery to the river by an estimated 50 tons per year.
Further, there is quite a bit of vegetation along the river and undeveloped land in the watershed (the area of land that drains to the river). Both Murphy-Hanrehan and Cleary Lake Regional Parks, operated by the Three Rivers Park District, are located in the watershed. In the southern reaches of the Credit River there are a number of large wetland complexes, and there is a vegetated streamside corridor along much of the river through the urban areas – particularly around Hidden Valley Park in Savage. In addition, the Legends Club golf course is considered environmentally friendly, and is one of only a handful of Certified Audubon Cooperative Sanctuaries in Minnesota.
The bottom line? There are many reasons why the Credit River is no longer impaired, all of which are cause for celebration. More importantly, it shows that water quality goals can be achieved: To date, only a handful of the state’s water bodies have been removed from the impaired water list.
Funding assistance for the Utica Ravine Project was provided by the Minnesota Clean Water Fund through the Board of Water and Soil Resources.
Numerous organizations and individuals contributed to improving the Credit River. The City of Savage, the Scott Soil and Water Conservation District along with the Scott WMO have completed a number of water quality projects in the watershed. A number of landowners have also participated in the Technical Assistance and Cost Share Program of the Scott WMO, and the rain garden program of the City of Savage.
Technical Assistance and Cost Share Are Available
Both the City and the Scott WMO work with the Scott Soil and Water Conservation District to offer technical assistance and cost share to land owners to complete conservation practices.
Continue the Conservation Ethic
The Credit River has been removed from the Impaired Waters List for turbidity. However, this is just one water quality parameter. There may be other problems with the river that we don’t know about, or that are threatening. This means that we need to continue the conservation efforts. The Scott WMO with assistance from the Minnesota Pollution Control Agency completed a Credit River Water Quality Protection Plan. This Plan sets out a strategy for protecting the river that continues the activities that lead to the current condition, provides on-going technical and cost share assistance to land owners, and monitors water quality. Additional information on the Protection Plan can be found on the Scott County website under the Parks, Library & Environment tab, Watershed Management Organization.