A tree trench, often known as a “vertical raingarden,” is a system that consists of piping for water storage, structural soils and a tree. They offer more benefits than just managing stormwater runoff; they also get trees into urban environments.
The piping of a tree trench holds water after a rain event catching it before it goes to the catch basin and providing irrigation for a tree. The trees also have a great capacity for
filtering 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 than they can 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.
Benefits of Trees
A mature tree can provide many important benefits including carbon storage and energy absorption. It is useful in stormwater management because it consumes water as it falls and it decreases the velocity of rain as it falls. Trees can catch a significant amount of water as it falls (the leaf size is the biggest variable amongst the different kinds).
Other options are being explored to help sustain urban trees. Check out what the city of Minneapolis has done using trees for stormwater management.