A vacant lot along the east side of Eaton Wash in Pasadena is about to become a 3.5-acre public park with a stormwater treatment system buried underneath it. The Pasadena City Council has approved the Eaton Wash Stormwater Capture Project, which will transform the unused parcel just south of Del Mar Boulevard into open space featuring a community garden, a dog park, and a pedestrian bridge connecting to Eaton Blanche Park.
The plan pairs underground infrastructure with above-ground recreation. As reported by Urbanize LA, the project will divert, treat, and store water from the Eaton Wash before returning it to the channel. According to a City of Pasadena staff report cited by Citizen Portal, the system targets diverting roughly 307 acre-feet of stormwater and dry-weather flow annually — filtering and returning 207 acre-feet to the channel while infiltrating 101 acre-feet into the local aquifer.
A Massive Drainage Area Feeds Into the Site
The underground infrastructure is designed to handle runoff from an upstream tributary drainage area of approximately 10,294 acres, according to the City of Pasadena. The system targets heavy metals, trash, sediments, and nutrients before the water reaches Eaton Wash, the Rio Hondo, and eventually the Los Angeles River. Subsurface plans call for a concrete storage basin with a 3.4 acre-foot capture capacity. Construction staging details were not specified in the cited filings.
The site carries some history worth preserving. The 3.5-acre parcel at 3160 East Del Mar Boulevard previously housed the Pasadena Earthside Nature Center from 1971 until roughly 1995, and the new park design will incorporate preserved elements including the original Earthside Gateway and an outdoor science classroom, according to the Water Education Foundation.
Construction Timeline and Remaining Approvals
Construction is scheduled to begin in July 2027 and run for approximately 22 months, according to Pasadena Now's reporting on the timeline cited in the Urbanize LA coverage. Most of the adjacent Eaton Blanche Park will remain open during that period, with closures limited to the area around the pedestrian bridge landing construction zone.
The project still needs to clear several regulatory hurdles. Following the City Council's adoption of the CEQA Mitigated Negative Declaration in August 2026, the project requires final permitting and consultations with the U.S. Army Corps of Engineers, the California Department of Fish and Wildlife, and the Regional Water Quality Control Board before it can return to council for a construction contract award, as outlined by Pasadena Now.
Funding Comes From County Parcel Tax and State Grant
Los Angeles County's Measure W provided $2.3 million toward the project's design and engineering, while Caltrans is set to contribute $6.5 million for construction, per the facts laid out by Urbanize LA. Measure W is also cited as a source of funding for the project.
Stormwater capture projects like this one across Pasadena must account for regulatory compliance requirements. The Eaton Wash park's above-ground design includes community gardens, a dog park, and demonstration gardens, and the City of Pasadena conducted community outreach and received community input during the planning process.
A Smoother Path Than the Arroyo Seco Project
The Eaton Wash project's relatively smooth path through CEQA review and council approval stands out compared to Pasadena's other major stormwater initiative along the Arroyo Seco, which has encountered legal and political challenges. Pasadena continues to pursue green space and stormwater capture infrastructure along the Arroyo Seco even as that project faces those challenges.
