Safe Clean Water Program: Spotlight on the MacArthur Lake Stormwater Capture Project
Safe Clean Water Program: Spotlight on the MacArthur Lake Stormwater Capture Project Image

MacArthur Lake’s story begins more than a century ago, when it sported a different name, a different footprint and a different purpose. 


Originally named Westlake Park, it was one of three reservoirs, along with Echo Park Lake and Lincoln Park Lake, built in the late 1800’s. Together, this trio of lakes provided water for LA’s growing population, while their surrounding parks offered green space and recreational opportunities. 


Westlake Park in the early 20th century was the place to be and be seen. Residents of LA’s prominent Westlake neighborhood strolled lakeside, enjoyed paddle boats and admired the park’s diverse tree collection, gathered from all over the world. In 1934 a berm was built, which allowed Wilshire Boulevard to run through the park, linking the westside of LA with Downtown. In 1942, Westlake Park was renamed for General Douglas MacArthur and in 1972, MacArthur Park with its lake was designated City of Los Angeles Historic Cultural Monument #100. 


Today conditions at MacArthur Park and its lake are vastly different and in need of some TLC. While it still provides green space for the many Angelenos who live within a 1-mile radius, the park and lake experience ongoing challenges related to its location in a densely populated urban area. 



In 2016, in response to Mayor Eric Garcetti’s directive to offset potable water usage in City parks, LA Sanitation & Environment (LASAN) installed a new water treatment system at MacArthur Lake using pressure sand filtration and ultraviolet disinfection to improve the lake’s water quality. Additionally, an LASAN retrofit project enabled the park to be irrigated with treated water fed by the lake’s overflow line.

In November 2018 Los Angeles County voters passed Measure W, which created the Safe Clean Water Program to provide approximately $285 million in annual, dedicated funding countywide for nature-based projects that increase local water supplies, improve water quality, provide community enhancements, protect public health and support compliance with federal clean water mandates. Simultaneously in late 2018 and early 2019, a series of MacArthur Lake charrettes provided the community with the opportunity to envision MacArthur Park and Lake’s future. The charrettes were vital in identifying and evaluating stormwater capture opportunities with community benefits.


A year later in 2019, LASAN submitted the MacArthur Lake Stormwater Capture Project for consideration for the Safe Clean Water Program’s inaugural round of regional funding, and in late 2020, the LA County Board of Supervisors approved approximately $20 million in Safe Clean Water Program regional funding for the MacArthur Lake Rehabilitation Project. 


State-of-the-Art Nature-Based Technologies


“The funding provided by the Safe Clean Water Program will allow LA Sanitation & Environment to focus on additional improvements at MacArthur Lake that will build on past work,” stated Enrique Zaldivar, Director and General Manager of LASAN. “As a flagship project for the City’s Safe Clean Water Program, the MacArthur Lake Stormwater Capture Project will utilize state-of-the-art nature-based technologies to improve water quality, while mitigating downstream flooding and creating recreational and resiliency benefits for the local community,” continued Zaldivar.


The objectives of the MacArthur Lake Stormwater Capture Project include:


  • Improve lake water quality; 
  • Offset potable water use by using captured stormwater; 
  • Enhance the park through sustainable greening and nature-based solutions;
  • Increase regional educational opportunities; 
  • Improve the recreational value of the park; and,
  • Achieve federal regulatory compliance for the Ballona Creek watershed.


Once complete, the MacArthur Lake Stormwater Capture Project will work to capture and store rainwater and improve the environment. Here are the goals:


  • Capture and store stormwater during rain events to replenish the lake’s water levels and irrigate the park, reducing the park’s use of potable water;
  • Remove trash, oil and grease, nutrients, bacteria, metals and hydrocarbons  from the polluted urban runoff flowing from an adjacent 216-acre watershed;
  • Divert stormwater to the Hyperion Water Reclamation Plant for treatment and use;
  • Construct nature-based solutions (e.g. bioswales, wetlands) to improve the lake’s water quality.


This project will also set the stage for future projects aimed specifically at enhancing and revitalizing the park as well as establishing connectivity with Lafayette Park and future adjacent green streets, which is a stormwater management approach that incorporates trees and shrubs, soil, and engineered systems to slow, filter and clean stormwater runoff from sidewalks and streets.


Benefiting Angelenos and Los Angeles


The MacArthur Lake Stormwater Capture Project will provide a wide variety of long-term benefits for Angelenos and Los Angeles. It will feature a direct positive impact on the local community by making the area a much more enjoyable natural space, allowing for increased recreation, restoring lake habitat and encouraging the park’s biodiversity. Environmental education in the neighboring community will offer future generations the opportunity to learn about MacArthur Lake and the nature-based systems at work.


The project will also improve the quality of our city’s environmental infrastructure.  By increasing the rate by which stormwater is diverted and/or captured, the project will alleviate the effects of local flooding and reduce the amount of potable water used to irrigate the park and fill the lake. 


A requirement of any Safe Clean Water Program-funded project is its accounting for how it will affect development within the local community so any concerns that residents may have about gentrification and/or displacement caused by this project will be addressed. Additionally, both the City of Los Angeles and the Safe Clean Water Program require the hiring of local firms, so the MacArthur Lake Stormwater Capture Project will bring much-needed jobs to the community. 


As the City of Los Angeles moves forward with this project, history should serve as the path to the future. The community surrounding MacArthur Lake has a rich history, which has evolved and changed over time. This change is reflected in the diversity of the land uses surrounding the lake as well as the Angelenos who call the adjacent neighborhoods their home. This rich history should be used to tell the story of the park and lake, tracing that excitement from the founding of the park in the late 1880s to what the future could look like with the proposed park and lake improvements. 


Because of the breadth and size of the MacArthur Lake Stormwater Capture Project, this project will take approximately five years to complete; however, LA Sanitation & Environment is confident that once finished, MacArthur Lake will welcome families, children and the community at large and reclaim its place as one of LA’s great regional destinations.  


If you would like to receive periodic updates on the MacArthur Lake Stormwater Capture Project, please send us an e-mail at and we’ll place you on the project stakeholder list.


Funding for the MacArthur Lake Stormwater Capture Project has been provided in full or in part from the Los Angeles County Flood Control District’s Safe Clean Water Program.

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