Pasadena to Mobilize to Defend Its ‘Greatest Environmental Treasure’

Climate trends and urban development are wielding effects on Pasadena’s Arroyo Seco, prompting residents to take direct action in defending what officials call the city’s “greatest environmental and recreational treasure.”

On Saturday, Sept. 27, volunteers will converge on the historic watershed for a critical cleanup effort aimed at reducing wildfire risks and protecting native biodiversity — challenges that have grown increasingly urgent as California’s fire season extends and intensifies.

“The Arroyo Seco is Pasadena’s greatest environmental and recreational treasure, and it belongs to all of us,” said Daniel Rossman, executive director of the One Arroyo Foundation, the nonprofit coordinating the effort with the city. “This Public Lands Day, join your community to play an active role in protecting this landscape and ensuring it remains safe, accessible, and thriving for future generations.”

The two-hour morning event, scheduled from 9 a.m. to 11 a.m. at the Casting Pond Parking Lot, 415 S. Arroyo Blvd., coincides with National Public Lands Day but addresses distinctly local pressures on Pasadena’s iconic natural corridor.

Volunteers will improve fire safety, enhance trails, and support local habitat health by clearing brush, removing invasive plant species, and collecting debris along trails. Efforts will directly contribute to biodiversity and reduce wildfire risks while preserving accessibility for future generations.

“We invite everyone to join us this Public Lands Day to help care for the Arroyo Seco—one of Pasadena’s most treasured natural spaces,” said Koko Panossian, director of Pasadena Parks, Recreation and Community Services.

“With One Arroyo as a dedicated partner in preservation, we’re working together to protect this vital resource for generations to come. Every pair of hands makes a difference. Whether you come solo, with friends, or as a family, your efforts will help support native plant biodiversity, reduce wildfire risks, and demonstrate the power of community stewardship in preserving our shared public lands.”

The volunteer effort is open to all ages, though participants under 16 must be accompanied by adults. Organizers require closed-toed shoes and long pants; volunteers should bring hats, sunscreen, and water bottles for sun protection.

The One Arroyo Foundation — a nonprofit dedicated to preserving, protecting, and celebrating Pasadena’s iconic Arroyo Seco — promotes stewardship, ecological restoration, and public engagement throughout the watershed, viewing community participation as essential to preservation efforts that no single agency can accomplish alone.

Registration for the free event is available at bit.ly/ArroyoPublicLands25.

Additional information is available through the City of Pasadena at 626-744-7311 during business hours or www.cityofpasadena.net.

The Casting Pond Parking Lot is at 415 S. Arroyo Blvd., in Pasadena.