California Department of Transportation
 

LID Parking Lot Stormwater Planter

 

Parkinglot Planter
Caltrans District 11 Parking Lot Stormwater Planter.  Photo source: WRT Design

 

Detail
Example: Parking Lot Stormwater Planter Detail.  Source: City of Portland


Parking Lot Stormwater Planters:

Caltrans Landscape Architects are often involved in the design of parking lots for safety roadside rest areas, park-and-ride facilities, vista points, and other state facilities.  Besides providing a place to park cars, parking lots can also be designed to incorporate LID strategies to manage stormwater.  One approach is to integrate stormwater planters between parking rows or at the perimeter of parking areas.  On the surface, parking lot planters look like attractive landscaped areas.  Below the surface, the planters include geotextiles, gravel, and soil to provide stormwater treatment through detention and infiltration.  Landscape Architects must work closely with their Project development Team to identify opportunities to include parking lot stormwater planters.

Stormwater runoff from the parking lot is directed into the planter, where it is temporarily detained, filtered, and infiltrated.  The planter soil surface is lower than the adjacent paved parking surface.

Below are links to design guidance and construction details for parking lot stormwater infiltration planters. 

The City of Portland, Bureau of Environmental Services, Stormwater Management Manual, Typical Details, Appendix G.3, Planters, Sheets SW-140 and SW-150- http://www.portlandonline.com/bes/index.cfm?c=47963&a=202914

California Stormwater Quality Association, LID Parking Lots- https://www.casqa.org/LIDDemo/LIDToolBox/IntegratingLIDintoSiteDesign/tabid/247/Default.aspx

EPA- Stormwater Menu of BMPs, Green Parking- http://cfpub.epa.gov/npdes/stormwater/menuofbmps/index.cfm?action=factsheet_results&view=specific&bmp=89

EPA- Green Parking Lot Resource Guide- http://www.streamteamok.net/Doc_link/Green%20Parking%20Lot%20Guide%20(final).PDF

Completed in 2009, the award winning San Mateo County Sustainable Green Streets and Parking Lots Design Guidebook is an excellent resource- http://www.flowstobay.org/documents/municipalities/sustainable%20streets/San%20Mateo%20Guidebook.pdf