A thriving rain garden installed in Columbia Heights in 2018. With proper maintenance, native species planted in rain garden will fill the entire space within ~3 years.

Four rain gardens are being installed in a northern Anoka neighborhood as part of the City's 2022 Street Surface Improvement Project. Collectively, these gardens will capture nearly 10 acres' worth of stormwater runoff (over 700,000 gallons annually) which would otherwise drain untreated to the Rum River. Through this, sediment loading to the river will be reduced by 969 pounds/year, and total phosphorus loading will be reduced by 3 pounds/year.

Each garden will provide additional ecological benefits through the planting of a diverse range of native species, creating several hundred square feet of rich pollinator habitat within the Rum River corridor. 

Funding for project design was provided by the Metropolitan Conservation Districts Engineering and Technical Assistance Program, and funding for construction is provided by the City of Anoka and State Watershed-based Implementation Funding. 

The Rum River in Isanti County

When allowed to wander freely, rivers flowing throughout a gently sloped landscape form a snakelike meandering path. This occurs as the fastest moving waters erode banks along the outer bends, and slower moving waters deposit sediment along the inner bends. Over many years, these processes cause the meanders to curve more intensely, causing the river to eventually loop back onto itself and cut a straight path through the narrow slice of land that remains. Now disconnected from the river, the C-shaped meander scar is called an oxbow.

To watch these processes in action, check out this video: Why Do Rivers Curve?

A quick glance at aerial imagery reveals numerous oxbow wetlands alongside the Rum River. They are rich in plant and animal life, serving as a "nursery" for fish, invertebrates, and amphibians in their early life stages while providing habitat for countless migratory bird species. These oxbows also improve water quality and reduce flooding by capturing water and the contaminants it carries following large storm events.

To learn more about the importance of oxbow wetlands and their utility in water resource management, read the Nature Conservancy's article on the topic here: What is an Oxbow? 

Image sourced from MNDNR Stream Habitat Program

Last year, over 3,000 linear feet of cedar tree revetments were installed on the banks of the Rum River in Anoka County. While the cedar trees themselves will help capture sediment and prevent further erosion throughout the coming years, the re-establishment of native riparian vegetation is essential for promoting long-term bank resiliency. In May, ACD staff, with assistance from Anoka County Parks staff, planted a total of over 1,000 plants across six cedar revetment sites; species planted included sandbar willow, red osier dogwood, false indigo, and buttonbush (pictured below). 

When present, the deep roots of native trees, shrubs, grasses, and other vegetation act like a net, securing the bank's soils and preventing them from washing away. Streambank vegetation also provides essential habitat for many aquatic and terrestrial species. For these reasons, ACD incorporates native plantings into all streambank stabilization projects.

An actively eroding bank on the Rum River

Photos collected from near-shore zones on surface waters throughout the county serve as valuable tools for assessing lakeshore and riverbank conditions. Following a day in the boat with a 360° camera, these photos are uploaded to Google Street View, making them accessible to anyone. ACD then uses these them to compile erosion inventory reports, which describe erosion severity and stabilization project needs on high-priority waterbodies such as the Rum and Mississippi Rivers. Updated photos for these rivers were collected throughout the first week of May and are now available to view (alongside those captured in previous years) on Google Maps.  

While browsing through these photos, you are sure to see a beautiful river view. You may also notice banks currently experiencing noticeable erosion or, alternatively, portions that have recently been stabilized and planted with native vegetation.