The Waite Park neighborhood is home to a unique example of green infrastructure designed to reduce flooding, add habitat, and help protect the Mississippi River.

The Hoyer Heights Tree Trenches were installed by the City of Minneapolis as part of a street reconstruction project in 2020. Supported by grants from the Mississippi Watershed Management Organization and the Minnesota Clean Water Fund, the pilot project is among the first in the city to capture and treat street runoff using this type of green stormwater infrastructure. It’s part of the Northeast Stormwater Management Initiative, which aims to reduce flooding and improve water quality and habitat in portions of Northeast Minneapolis and Columbia Heights.

Dirty runoff from the streets flows into the tree trenches via curb cuts. Native plants and trees in the trenches absorb the water, while sediment traps and the soil filter out pollutants. A perforated pipe underdrain allows the cleaned stormwater runoff to drain through the storm sewer system to the Mississippi River.

An MWMO video provides an overview of how the tree trenches work as well as the basic maintenance techniques involved in keeping the functioning. As you can see from the video, the native plants have proven to be remarkably resilient, bursting with flowers and buzzing with pollinators in spite of last year’s drought.

The MWMO is planning to host a tour of the project later this summer. This will be an opportunity to learn how the tree trenches work as well as how they’re maintained. Contact MWMO Training and Community Learning Specialist Abby Moore at amoore@mwmo.org if you’d like to learn more.

—Submitted by the Mississippi Watershed Management Organization