• Canoeists paddle by tree lined shores

    Saint Croix

    National Scenic Riverway WI,MN

Water Quality

The St. Croix River is known as one of the cleanest rivers in the Midwest. Yet all is not well, even with the St. Croix. In 2006 Wisconsin and Minnesota signed an agreement to work toward a 20% reduction in phosphorus loading in the St. Croix River Basin. This will help restore the St. Croix to a level closer to what existed in the 1940's. more...

During the summer, increased nutrients in the water can lead to a blue-green algae bloom learn more...

A Habitat Classification Report looks at the rivers and divides them into segments. This may help you better understand the rivers in regard to water quality. more... This document also has appendices.

The St. Croix's water quality is a major factor in the St. Croix having a mostly intact mussel population. This includes 40 species, two of which are on the endangered species list. Learn more about mussels.

The United States Environmental Protection Agency maintains web sites with information pertaining to the St. Croix and Namekagon Rivers.

Information and resources highlighting the Namekagon Watershed.
Information and resources highlighting the Upper St. Croix Watershed.
Information and resources highlighting the Lower St. Croix Watershed.

Did You Know?

two men with a circular ice saw.  In the background blocks of ice are moving up a ramp into an ice house

Before the invention of refrigerators, people harvested ice from rivers and lakes in the winter and stored the ice, covered in sawdust, in buildings. An ice house, storing ice from the river, once stood near the site of the park headquarters for St. Croix NSR, in St. Croix Falls, Wisconsin.