The new streetside garden that is in front of our offices is enjoying the new rain. Which is exactly what it is supposed to do!
Streetside gardens do a lot. They beatify neighborhoods, add property value, and calm traffic. Yet, the real potential in streetside gardens is their ability to capture and retain the rainwater that falls onto the sidewalk. By catching the water before it runs into the gutter and then sewer, the water is kept from needing treatment before being released into the bay. The water is retained where it falls and filters into the soil. It percolates underground and restores or helps maintain the natural water table.
As water runs across the sidewalks and streets, it picks up pollutants such as oil and gas from cars and chemicals applied to yards and homes. By catching this water, streetside or other kinds of rain gardens avoid spreading these pollutants into the watershed. The water along with the pollutants are filtered by the soil. Many pollutants are then remediated or decomposed by microbes in the soil.
Cities across the country are now changing their approach to water drainage management. Where the old approach was to catch water and divert it quickly into gutter and drains where it ultimately was collected into storm drains, the new approach is to slow the travel of water and give it as many opportunities to filter into the soil before it reaches the gutters and drains. San Francisco, New York, Los Angeles, and Portland are all cities that are promoting this new approach.
Check out this great video. One of the sections highlights a cool new project in Manhattan that aims at converting the unused street space in front of fire hydrants into rain gardens.