The Central Arroyo Stream Restoration Program (CASRP)

Arroyo ChubThe Central Arroyo Stream Restoration Program (CASRP), developed in implemented in 2006-2008, has been a milestone the in Arroyo Seco and Los Angeles River revitalization program. CASRP has improved trails, stream habitat and water quality within the Central Arroyo Seco in Pasadena. Located within the Arroyo Seco Watershed, the Central Arroyo Seco subwatershed begins immediately below Devil’s Gate Dam and terminates at the Colorado Street Bridge crossing.


Water quality within the Arroyo Seco is heavily impacted by pollutants contributed from the highly urbanized environment through which it flows. The removal of riparian vegetation in the Central Arroyo Seco has significantly impacted wildlife and plant diversity. Urban development and exotic plant species have replaced native vegetation below the dam. The riparian habitat within the watershed has been reduced to 15% of historical cover due to encroachment by urban land uses.

CASRP, which was completed in the summer of 2008, has five major components:

  1. Stream and Habitat Restoration South of Devil's Gate Dam
  2. Brookside Park Parking Lot Water Quality Islands
  3. Stream Reconfiguration and Backwater pools south of the Rose Bowl
  4. Trail Improvements in the Central Arroyo
  5. Trash Capture Devices in storm inlets throughout Pasadena.

Project Background and Funding

CASRP is a watershed management implementation program to build on previous watershed and water quality planning efforts including the U.S. Army Corps of Engineers Arroyo Seco Watershed Restoration Feasibility Study and the City of Pasadena’s Arroyo Seco Master Plan and Program Environmental Impact Report (EIR). Coordination with regulatory agencies and watershed stakeholders resulted in the design of the project.

In late 2006, The State Water Resources Control Board, awarded a grant in the amount of $1.93 million. The City of Pasadena provided match funding of $643,000 for the project. The group retained Camp Dresser & McKee Inc. (CDM), which helped shape the proposal, to design and assist with implementing the goals of the program. Working on a tight schedule, ASF and CDM deliverd this exciting project on time and within budget.

CASRP included extensive community outreach and the development of video, A River Comes Alives.

Stewards of the Arroyo Seco, PO Box 92722, Pasadena, CA 91109-2722 info@arroyoseco.org