skip to Main Content
Back to: About


Perhaps no other river captures Southern California’s imagination like the LA River.

The LA River offers an opportunity to bring 17 municipalities and countless communities together. Unlike highways that divide communities, the river can be a connector, bringing people together across 51 miles. This capacity was recognized in the seminal Olmsted-Bartholomew 1930 regional plan Parks, Playgrounds, and Beaches for the Los Angeles Region. That plan, completed at the start of the Great Depression and just before the catastrophic floods of the 1930s, foresaw the rapid urbanization of LA County. Olmsted and Bartholomew recognized that parks, open spaces, and connection to nature would be essential to the health, environment, and economy of the region. Unfortunately, the Olmsted Bartholomew plan was largely unimplemented. Given the large cost of the plan, there were challenges with which governing body would take it on and the need for a new governance structure.1For a more complete discussion of the Olmsted Bartholomew Plan and why it was not implemented, see: Deverell, William. (2013). “Dreams Deferred.” Overdrive: L.A. Constructs The Future 1940-1990. Los Angeles: The Getty Research Institute. pp.22-33. While a few parkways and reserves were created, much of the LA region’s urbanization was driven by other development strategies and the LA River was fully channelized in the following decades without the envisioned greenway.

Bicycle trails allow cyclists to utilize the river right-of-way near river mile 10.8.
LA County Public Works, 2018.

In 1996, LA County rediscovered the ambitions of these past planning efforts and created the first LA River Master Plan. Numerous residents, communities, and advocates have pushed for an inclusive vision of shared public open space and parks, stewardship of precious water resources, improved ecosystem function, and continued flood management during extreme storm events.

The LA River Master Plan builds on this history of planning and includes over two decades of planning and implementation efforts for the LA River, including efforts by LA County (1996), the City of LA (2007), the LA River Ecosystem Restoration Feasibility Study (also known as the ARBOR Study, 2015), the Lower LA River Working Group (2018), and the Upper LA River and Tributaries Working Group (2019). The research and project database that forms the foundation for this plan covers over 140 planning efforts along the LA River channel, across the LA River watershed, and throughout the region.


The LA River is 51 Miles in length, running from Canoga Park to
Long Beach


There are 2,300 acres of primarily publicly owned land within the right-of-way, including the
river channel.


There are nearly one million people2This is an estimate based on population data from the US Census Bureau’s American Community Survey 2015-2019 5-year estimates. The number of residents living within block groups that intersect a one-mile buffer around the LA River totals 1,132,184 people. An analysis considering only the proportional share of block group population within a one-mile buffer of the river based on the proportional share of residential land uses within block groups yields 875,006 people living within one mile of the LA River. Residential land uses include parcels with a “Residential” use type as well as parcels with use codes indicating retail/residential mixed use, office / residential mixed use, nursing home, home for the aged, or public housing based on LA County Assessor parcel data. Therefore, the number of people living within 1 mile of the LA River is between approximately 875,000 and 1.1 million. that live
within one mile of the LA River.

The Master Plan Update process began in 2016 with a motion by the Board of Supervisors to update LA County’s 1996 LA River Master Plan. The update process, led by LA County Public Works, was supported by several LA County departments. A steering committee of 41 members representing municipalities, non-profit organizations, or other governmental and non-governmental entities provided input and expertise related to water, people, or the environment. In addition to the technical team and steering committee, the update process included a robust public engagement program designed to provide opportunities for LA County residents to express ideas for the future of the river.

The LA River Trail often follows the top of the levee, especially in the Lower LA River. In this image, the landside of the levee is also fortified at river mile 11.7.
LA County Public Works, 2018.

The Master Plan research and analysis is based on a watershed and community approach. This approach is unique from previous efforts in that analysis work, including ecosystem, demographic, and hydrologic studies were conducted for the 834-square-mile watershed. Recognizing that these systemic and natural elements cannot be studied in isolation, several studies included information for areas outside the watershed. This research is now publicly available and can be utilized for parallel efforts within the watershed.

The Master Plan research and analysis is based on a watershed and community approach

There is no singular, 51-mile design strategy for the LA River. Projects along the river should reflect the needs and opportunities of specific reaches and provide multiple benefits. Projects should respect the needs of flood risk management while enhancing the environment and strengthening communities through multi-benefit investment and the celebration of local cultures and creation of jobs. While design strategies in the Master Plan focus on elements along or within the river right-of-way,3The LA River right-of-way is within the operations and maintenance jurisdiction of LA County Public Works (on behalf of the Flood Control District) and the United States Army Corps of Engineers (USACE). the Master Plan’s vision, goals, actions, and methods require an understanding of, and coordination with, communities, the watershed, and parallel efforts such as the Upper LA River and Tributaries Working Group, the Lower LA River Working Group, Metro, the Regional Water Quality Control Board, the LA County General Plan, the LA County Sustainability Plan, the City of Los Angeles’ LA River Revitalization Master Plan, the LA County Comprehensive Parks Needs Assessment, the Department of Arts and Culture Cultural Equity and Inclusion Initiative, and watershed management plans. Additionally, coordination between LA County, municipalities, other governmental entities, and non-profit organizations will be necessary to achieve the robust vision and goals of this Master Plan. The reimagined LA River relies on these collective efforts to shape the future of the LA River, its watershed, and all of LA County.

Project Themes

The Master Plan process was guided by three overarching and coequal themes–water, people, and environment. At the heart of this plan is the realization that infrastructure planning cannot be isolated from social and environmental needs. The full integration of the three themes is fundamental to the LA River’s success.

The three themes proved both broad and robust enough to capture the key issues from the 1996 plan as well as from related plans that were part of a literature review for the update. They ensured that the Master Plan balanced but did not isolate hydrological, social, and environmental needs.

Back To Top