Integrated Tree Trench System
The tree trench system is comprised of a treatment train of practices to maximize collection and treatment of stormwater runoff from sidewalks and streets. Stormwater runoff from the sidewalk drains through permeable pavement, which provides water for street trees planted in structural soils. Excess water not taken up by the trees then flows through the structural soils which are underlain by infiltration trenches that allow for additional stormwater volume storage and infiltration. Stormwater runoff from the streets is also directed to the infiltration trenches via catch basins.
Stormwater planters are small, contained vegetated area that collects and treats stormwater runoff using bioretention. Bioretention systems collect and filter stormwater through layers of mulch, soil and plant root systems where pollutants are retained, degraded and absorbed.
Infiltration trenches are underground features one-foot or more in depth that are first excavated and then lined with filter fabric on the top and sides. The trenches are filled with stone to create underground reservoirs for stormwater runoff from a specific design storm. The runoff gradually percolates through bottom and sides of the trench into the surrounding subsoil.
A rain garden is a shallow, constructed depression to catch rainwater. It contains plants that tolerate standing water for several hours and will drain out of the garden within 48 hours. Raingardens slow and infiltrate stormwater, help prevent erosion and remove pollutants while providing beautiful landscaping and wildlife habitat.