Watershed Rehabilitation: Oros Green Street Project

Elysian Valley, Los Angeles


Project Funded by:

• State of California Proposition 13 Grant
• Federal Clean Water Act 319(h) Grant
• City of Los Angeles Prop. O funds

The Oros Green Street project exemplifies North East Trees’ commitment to transform the urban infrastructure from “gray” to “green”. The first Green Street in Los Angeles, this pilot project re-designed a residential street and park to manage storm and dry weather urban runoff in an environmentally sustainable way. This project demonstrates that best management practices (BMPs) based on biological treatment and filtration processes can be used to meet water quality objectives when distributed throughout mixed land use neighborhoods in urban settings.

Two different types of BMPs were specified to achieve this:

1. Bio-retention areas built into the parkways between the street and private property line called “stormwater gardens”, designed to capture the runoff from private residences.
2. An infiltration trench at the street end, designed to capture all street and excess private property runoff.


Installation of perforated pipes and gravel filter for the residential stormwater gardens built in to the parkways

between the street and private property line


Infiltration trench at street end park under construction


Completed stormwater gardens - native grasses and trench drains across driveways capture polluted

stormwater and allow it to infiltrate through underground perforated pipes and gravel into the ground


The infiltration trench in Steelhead Park captures stormwater runoff from streets and naturally cleans

it before it flows into the river. Water quality monitoring performed by North East Trees shows that 90%

of the pollutants are removed before the water drains into the Los Angeles River