A tree trench, often known as a “vertical raingarden,” is a system that consists of piping for water storage, structural soils and a tree. It manages stormwater runoff and promotes the use of trees in urban areas.
A tree trench holds water after a rain event, providing irrigation for a tree, and preventing stormwater from entering the stormdrain. Trees can also
filter out pollutants including heavy metals. Tree trenches can be found locally at the West End shopping area in St. Louis Park.
Urban trees are often replaced far before they can fully benefit the environment. They are often put in spaces that are much too small. Worse yet, they are often unable to benefit from rain water due to poor encasements. Tree trenches solve these problems allowing for trees that can live to maturity.
Learn more about building healthy, effective tree trenches in the Minnesota Stormwater Manual from the Minnesota Pollution Control Agency.
Benefits of Trees
A mature tree can provide many important benefits including carbon storage and energy absorption. It is useful in stormwater management because its leaves act as a buffer, slowing down the speed of rain as it falls, and absorbing it. Depending on their size, the leaves on trees can catch a significant amount of rainfall.
Other options are being explored to help sustain urban trees. Check out what the city of Minneapolis has done using trees for stormwater management.