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Case Study

Ed P. Reyes River Greenway, Los Angeles

Year: 2017
Associated Publication: Urban Street Stormwater Guide

EP Reyes Greenway (credit: LA Sanitation)

Project Area: 1.13 acres

Drainage Area: 135 acres

Right-of-Way Width: 100 feet

Participating Agencies: LA Bureau of Sanitation (LASAN), Watershed Protection Division

Timeline: Opened to public 2013

Cost: $3.4 million


Stormwater management: Capture all dry weather runoff from the project area.

Improve water quality: Divert and filter polluted stormwater to mitigate the highest bacteria point source before contaminants reach the Los Angeles River.

Increase open space: In a neighborhood of Los Angeles starved for open space and greenery, the stormwater facility serves a function akin to a public park and provides public access.


The project was identified by a regional study, Cleaner Rivers Through Effective Stakeholder TMDL’s, or CREST. The site is located on the north bank of the Los Angeles River in the Lincoln Heights community, a neighborhood underserved by open green spaces. The project is situated in an undeveloped section of right-of-way at the end of Humboldt Avenue, a location that has long been problematic for the City of Los Angeles for becoming an illegal dumping ground and hosting various encampments.

An existing storm drain spanning the project site delivered runoff from a 135-acre tributary to an outfall into the Los Angeles River. Stormwater runoff from streets and highways, industrial facilities, multi-family residential structures, and commercial structures conveyed pollutants to a federally regulated water body, enforced by the U.S. EPA.

Through a landscape interventions, this former brownfield site and storm drain was daylighted and transformed into an ecological resource closer to a natural tributary. Much of the site has been opened to the surrounding community as a community facility with walking paths and a small pedestrian bridge, with opening hours every day.

Design Details

EP Reyes Greenway (credit: LA Sanitation)

A hydrodynamic separator and a solar pump lift stormwater runoff from a wet well to a level spreader & spillway (“waterfall”). Water flows to a vegetated forebay in dry weather which provides year-round support for flora and fauna.

In wet-weather events, storm flows overtop a rock weir to infiltrate a sub-surface bio-infiltration gallery beneath 18” of vegetated soils. In extreme stormwater events, flows rise above grade to the standpipe, and flow to the Los Angeles River.

Lessons Learned

Have a clear plan for public access, operations, and maintenance. A security vulnerability initially limited public access to the site until a plan could be put in place for safe access.  Monitoring, operational training, and ongoing coordination between stormwater utility crews has enabled public access to the space during daylight hours, and extends public access in summer months. As the lead agency for the city’s stormwater compliance, LASAN is responsible for permit compliance, and so oversees operations and maintenance of the facility.


EP Reyes Greenway (credit: LA Sanitation)

The basin, storage and filtration structures detain approximately 50,000 cubic feet of stormwater runoff.

The project achieved full compliance for dry weather bacteria flows from the tributary to the Los Angeles River by capturing 100% of flows and filtering and using them to support the ecosystem functions.

The project is serving as a much-needed open space resource for a disadvantaged community.