Green infrastructure is a new generation of landscape designs that help improve water quality, prevent flooding and replenish ground water. These attractive solutions mimic drainage patterns of natural landscapes by using permeable pavement, depressions in the ground and other landscape designs that help divert water away from roads and other impervious surfaces. As a result, more rainwater is absorbed into and filtered by the soil, and less ends up as runoff that washes pollutants off streets and carries them through the storm drain system into creeks, wetlands and the Bay. Scroll down to learn more about typical green infrastructure features.
Stormwater Resource Plan (SWRP)
Throughout Alameda County, many green infrastructure projects have been put in place in recent years, and the list is growing. In order to receive state funding for new projects, the Clean Water Program has to develop a Stormwater Resource Plan (SWRP) that identifies potentially eligible green infrastructure projects in the county’s 17 jurisdictions.
Final SWRP incl. Appendices 1-4 - View or download (2.6MB)
Final SWRP Appendix 5: Prioritized Projects - View or download (22.6MB)
Some typical Green Infrastructure features include:
Rain gardens are shallow, vegetated basins that collect and absorb runoff from rooftops, sidewalks, and streets. Plants most suitable for rain gardens have deep fibrous roots, can withstand the extremes of moisture and drought, and tolerate pollutants typically found in stormwater runoff.
Stormwater Curb Extenions
Stormwater curb extensions are landscaped areas placed right next to the curb and designed to capture runoff from the street. Typically, the planted area is slightly lower than the street, with an opening in the curb to allow water to flow in. In addition to helping absorb and filter stormwater, curb extensions often make pedestrian crossings shorter and therefore safer.
Permeable pavement replaces impervious surfaces used for parking lots, roads and other paved areas. Made from porous asphalt, pervious concrete, pavers or plastic grids filled in with gravel or turf, permeable pavement allows rainwater to percolate into the ground below.
Green roofs are roofs covered with soil or soil-like substrate and plants growing in it. Green roofs can look and function like ground-level gardens—offering living and recreation space—or consist of only shallow substrate and hardy, drought-tolerant vegetation. Both types of green roofs collect and retain rainwater and reduce runoff, while providing wildlife habitat and improving aesthetics.
To see examples of “green infrastructure” in Alameda County, click here.