Thursday, September 3, 2026

L.A. County Breaks Ground on $63.7 Million Baldwin Lake Restoration at Arboretum, Summer Home of the Pasadena Symphony POPS

[photo credit: Los Angeles County Public Works]

Dredging starts this month at a lake that has silted in to about 3 feet deep; the county says the work will be done by the end of 2027, ahead of the 2028 Olympics

Los Angeles County officials broke ground Wednesday, Sept. 2, on a $63.7 million restoration of Baldwin Lake and Tule Pond at the Los Angeles County Arboretum and Botanic Garden in Arcadia, the outdoor summer home of the Pasadena Symphony and POPS and a project the county says has been more than a decade in the making.

Supervisor Kathryn Barger, whose Fifth District includes Pasadena and Altadena, joined county department heads, Arboretum leaders and community partners for the ceremonial groundbreaking, according to a news release from her office. A representative of the Gabrieleno San Gabriel Band of Mission Indians conducted a traditional land welcoming ceremony.

“This $63.7 million investment will protect a place that is part of the identity of the San Gabriel Valley and ensure it thrives for generations to come,” Barger said in the release. “We are investing in cleaner water, greater flood resilience, environmental restoration, and the long-term future of the Arboretum. After years of careful planning and partnership, today we are turning that commitment into action.”

The lake, dredged in the late 1880s to a depth of 12 to 15 feet, is now only about 2.5 to 3 feet deep because of accumulated sediment and organic material, according to the Arboretum. Since the 1950s, neighborhoods to the north have sent their street runoff into Tule Pond and the lake, contributing to soil contamination, while storm flows have eroded the shoreline, according to Los Angeles County Public Works. The result has been poor water quality, spikes in summer water temperature, little circulation and overgrown vegetation, the department said.

Baldwin Lake is a spring-fed sag pond with cultural roots reaching back to Native American settlements and the Rancho Santa Anita era, Barger wrote in a March 17, 2026, motion to the Board of Supervisors. Tule Pond, once an upstream extension of the lake, became hydrologically isolated in the 1950s and lost its flood-management function, the motion said. The Arboretum calls the lake its most endangered historic feature and has cited reports from the Pasadena Audubon Society of declining bird use at both the lake and the pond.

The project will dredge both water bodies to restore the lake’s historic depth, treat runoff before it enters the pond, stabilize the shoreline and restore the historic perimeter walls, and add circulation and aeration equipment, according to Public Works and the Arboretum. Deepening the lake and pond will let them hold more water, making them less likely to dry out in summer and better able to absorb heavy storms, with excess water discharged to Arcadia Wash, Public Works said.

“It is a critical refuge for wildlife in our highly urbanized region, providing essential habitat and an important stopover for migratory birds traveling along the Pacific Flyway,” said Norma E. García-González, director of the county Department of Parks and Recreation, in the release.

The construction budget combines $46.2 million from the Safe Clean Water District Program, $8.5 million from the Safe Clean Water Regional Program, $8 million from the Los Angeles County Flood Control District and $1 million from the Regional Park and Open Space District’s Proposition A program, according to the county.

Fencing went up around affected garden areas in July, and dredging is scheduled to begin in September, with trucks hauling sediment off site, the Arboretum said. Work will not take place on weekends, holidays or red-flag fire-weather days, and the garden will remain open during sediment removal. The county said construction is expected to be completed by the end of 2027, ahead of the 2028 Olympic and Paralympic Games; the Arboretum’s posted schedule lists October 2027.

Su Oh, the Arboretum’s chief executive officer, said in the release that the restoration “represents over a decade of work” and that the garden expects the restored lake “to serve as one of the primary draws for the LA28 Olympic Games.” The Los Angeles Arboretum Foundation funded an initial Baldwin Lake study in 2012, and a core sediment study of the lake and pond followed in 2015, according to the foundation’s Save Baldwin Lake campaign.

Mark Pestrella, director of Los Angeles County Public Works, said the project would improve water quality, expand stormwater capture and protect the historic water bodies. Justin Hutchings, president of the Arboretum Foundation, thanked the county and the project partners, Ames Construction and Studio MLA.

The Pasadena Symphony and POPS performs its Summer POPS series at the Arboretum and its Classics series at Ambassador Auditorium in Pasadena, according to the orchestra. Questions about the project can be sent to BaldwinLakeTulePond@dpw.lacounty.gov, and the Arboretum posts construction updates at https://www.google.com/url?q=https://arboretum.org/baldwin-lake-tule-pond-restoration-project/&source=gmail&ust=1788518925789000&sa=E.