A rain garden is a planted depression or a hole that allows rainwater runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and compacted lawn areas the opportunity to be absorbed. This reduces rain runoff by allowing stormwater to soak into the ground (as opposed to flowing into storm drains and surface waters which causes erosion, water pollution, flooding, and diminished groundwater). They can be designed for specific soils and climates. The purpose of a rain garden is to improve water quality in nearby bodies of water. Rain gardens can cut down on the amount of pollution reaching creeks and streams by up to 30%.
Rain gardens have been built in connection with several development projects. However, the City of El Cerrito has recently built two sets of rain gardens aimed at collecting and cleansing the rain runoff from public streets where many pollutants can be found. These can be found along the east side of San Pablo Avenue south of Madison Street and south of Eureka Avenue. The following video podcast provides an excellent depiction of how these rain gardens came about and how they work : Cut the Curbs to Claim the Rain
The City is also in the process of designing another rain garden to treat runoff from the public right of way along the Ohlone Greenway just south of Fairmount Avenue. This project, expected to be built in 2013, is part of an Urban Greening project (funded by Proposition 84).
Rain Gardens on San Pablo Avenue include:
South of Madison
South of Eureka
Rain Gardens along the Ohlone Greenway include:
South of Fairmount (Construction Due to Start in 2014)