County Puts $63.7 Million Into Baldwin Lake Restoration, Funded Largely by Regional Stormwater Tax

Los Angeles County is spending $63.7 million to restore Baldwin Lake and Tule Pond at the Los Angeles County Arboretum and Botanic Garden in Arcadia, with dredging scheduled to begin this month and about 86 percent of the money coming from the countywide stormwater parcel tax that Pasadena property owners help pay.

Of the $63,714,000 total, $54,714,000 comes from the Safe Clean Water Program, which is financed by the Measure W parcel tax of 2.5 cents per square foot of impermeable surface on private property throughout the Los Angeles County Flood Control District. Pasadena pays into that program and draws from it for its own stormwater projects. The county has also committed itself to maintaining the result for as long as a century.

The work will remove approximately 65,000 cubic yards of sediment from a lake the county says is now roughly 2.5 to 3 feet deep, down from the 12 to 15 feet Elias Baldwin dredged it to in the late 1880s. The lake covers 3.4 surface acres and the adjacent Tule Pond about 0.7 acres. Crews will install a liner and aeration units, rehabilitate the historic wall surrounding the lake, realign one storm drain outlet and reconstruct three others with energy dissipators, and install hydrodynamic separators and media filtration to treat residential runoff. Tule Pond, which the county says became hydrologically isolated in the 1950s and lost its flood management function, will be re-graded and dredged up to 12 feet so it can again serve as a pre-settling basin for water flowing into the lake.

The funding breaks into four parts. The Flood Control District contributes $8,000,000; the Safe Clean Water Regional Program $8,500,000, of which $3,770,000 was approved in fiscal year 2021-22 and $4,730,000 is to be received on CEQA approval; the Safe Clean Water District Program up to $46,214,000; and a Regional Park and Open Space District Proposition A grant $1,000,000 toward the historic wall. The construction contract itself was estimated at $20,000,000 to $30,000,000, with the balance of the total covering plans and specifications, construction engineering, inspection, contract administration, change order contingency, environmental compliance and other county services. The county states there is no impact to the General Fund.

The Board of Supervisors approved the project, certified the Final Mitigated Negative Declaration and adopted the Mitigation Monitoring and Reporting Program on March 17, on a motion moved by Supervisor Holly Mitchell and seconded by Supervisor Kathryn Barger, who represents the Fifth District where the Arboretum sits. The environmental review, tracked under state clearinghouse number 2024110093 with the Flood Control District as lead agency, identified potentially significant effects in aesthetics, biological resources, cultural resources, noise and tribal cultural resources, and concluded that all of them could be reduced to less than significant with mitigation.

Four comment letters were filed during the public review period that ran from November 1 to December 2, 2024 — one from an organization and three from individuals — raising concerns about tribal cultural resources, traffic and transportation, and biological resources. Two tribal groups requested consultation under state law. The county record states that consultation with the Gabrielino Tongva Indians of California was completed through agreement, and that consultation with the Gabrieleno Band of Mission Indians – Kizh Nation was closed by a good faith determination, after reasonable efforts, that an agreement could not be reached.

The Wednesday event at the Arboretum will see Barger, Parks and Recreation Director Norma E. Garcia-Gonzalez, Arboretum Chief Executive Su Oh, Public Works Director Mark Pestrella and Justin Hutchings, whom the announcement identifies as president of the Los Angeles Arboretum Foundation, along with a tribal land welcoming by a group the announcement names as the Gabrieleno San Gabriel Band of Mission Indians.

The county has committed to the site well past construction. A Funding, Use and Maintenance Agreement between the Flood Control District and the parks department sets an initial 50-year term with extensions in 10-year increments to a maximum of 100 years. Parks will maintain the landscaping, irrigation, pond and the lake aeration and algae remediation systems; the district will maintain the storm drainpipes, manholes and catch basins. Excavated material will go to Waste Management facilities in Simi Valley and Kettleman City under agreements capped at $7,000,000, with amendments limited to a further $500,000. Because Proposition A money is involved, the board adopted a youth employment plan for the project; it states that no youth will be employed, on the ground that the work is specialized.

The Arboretum draws more than 500,000 visitors a year, most from the San Gabriel Valley, East Los Angeles and the Inland Empire, and 242 schools visited in 2022, more than 75 percent of them Title 1. The garden says it will stay open through the sediment removal, with hauling Monday through Friday from 7 a.m. to 4 p.m., no weekend or nighttime work, and none on holidays or red flag warning days. Parking remains in the Main and South lots and most routes stay open. Sediment found to be contaminated with lead will go to a hazardous-waste facility, and the garden says the environmental review found no danger to visitors, neighbors, drinking water or air quality because material will be contained under strict guidelines.

Baldwin Lake is listed on the National Register of Historic Places as a support feature for the adjacent Queen Anne Cottage and Coach Barn, and the county describes it as a spring-fed sag pond on a site that held a Native American settlement before the Arboretum was created in 1947. “The lake is our most endangered historic feature,” the Arboretum says on its project page. In a written statement quoted by the garden’s former chief executive in an undated Foundation column, Barger told the Arboretum she was “happy to assist you in preserving it for the enjoyment of future visitors.”