Imperial Highway Sunken Median

The Imperial Highway Sunken Median project retrofitted approximately 1.3 miles of Imperial Highway (from Pershing Drive to California Street) with a sunken median infiltration system and vegetated buffer strip. 
Runoff from this transportation corridor historically contained pollutants such as oil, grease, suspended solids, metals, gasoline and pathogens. This project diverted the polluted surface runoff from 11 acres into the median where vegetated filter strips and grassed filters now filter the polluted flow. Additional filtration takes place in infiltration trenches that have been lined with filter fabric and back-filled with stone to form an underground basin. This system removes soluble and particulate pollutants from runoff before it flows onto Dockweiler State Beach.


Imperial Highway Photo


  • Imperial Highway between Pershing Drive and California Street in Council District 11

LA Sanitation and the City of Los Angeles Bureau of Engineering partnered on this project.

Proposition O provided $2,723,403 in funding for this project. No additional funding was utilized.