Arroyo Seco Foundation

Old Marengo Park Cleanup & Fall Planting

Sunday, Nov. 29, 2015, 9 am
Corner of Woodbury and Marengo, Pasadena/Altadena

Join Altadena Heritage, the Arroyos & Foothills Conservancy and the Arroyo Seco Foundation for a wonderful neighborhood event to beautify Old Marengo Park! Help us to clear weeds, clean up the park, and put beautiful native plants into the ground just in time for the winter rains. Throw some California poppy seeds and watch them come up in the spring! Old Marengo Park is located at the intersection of Marengo Ave and Woodbury Road on the boundary between Pasaden and Altadena. Event is free and open to the public.

Who's Your Favorite Arroyo Star?

Each year we give out the Arroyo Verde Awards to deserving people, agencies, organizations and businesses. Who do you think has made a valuable contribution to the Arroyo this year? Please submit your favorite candidates here.


The Acorns Are Dropping!

All across our region, the acorns have begun to drop. Short stubby Engelmann acorns or the more elongated acorns from the dense Coast Live Oak (quercus agrifolia).

We will be collecting acorns during autumn to propagate at the Hahamongna Nursery. If you would like to get involved, please contact

Learn More about the Stately Engelmann Oak

No Big Dig! Lawsuit Update

There have been several changes regarding the court hearing on the lawsuit regarding LA County Flood Control District's program to excavate 2.4 million cubic yards of sediment from behind Devil's Gate Dam in Hahamongna Watershed Park and to truck it to distant landfills. There is now a new judge and the initial hearing has now been backed up until some time in the late Spring or early summer of next year. wsuit, filed by the Arroyo Seco Foundation and Pasadena Audubon Society last December to challenge the enormous impacts of the County's program on Hahamongna and the surrounding neighborhoods including west Pasadena.


Haha Lawsuit: What's It All About?

Here's the news briefing explaining the Hahamongna sediment lawsuit filed by the Arroyo Seco Foundation and the Pasadena Audubon Society against the Los Angeles County Flood Control District sediment mining and trucking operation from behind Devil's Gate Dam in Hahamongna Watershed Park. ASF's Tim Brick, Laura Garrett, Conservation Chair of PAS and attorney Mitchell Tsai are featured in the video explaining their concerns and the issues that will be contested in the No Big Dig lawsuit.

The Trucks Are Coming! 50,000 a Year!

County Releases Devastating Hahamongna Sediment Trucking Plan

LA County Flood Control District's sediment removal program for Devil's Gate Dam in Hahamongna Watershed Park is deeply flawed. It's an old-style mining and trucking operation with devastating impacts on the nature and character of Hahamongna Watershed Park and on the surrounding communities.

Arroyo Seco Canyon Project

The Canyon Project is an innovative program to improve water resources and environmental conditions in the Arroyo co-sponsored by the Arroyo Seco Foundation and Pasadena Water & Power Department.


Arroyo Seco Excised from San Gabriel Mountains National Monument

By a mysterious process that no one will explain, the Arroyo Seco and the southwest corner of the Angeles National Forest were eliminated at the last minute from the newly announced San Gabriel Mountains National Monument.


Introducing Stewards of Public Land

Pasadena Council Says Archers Only!

We were disappointed by the Pasadena City Council vote to cede a large portion of the Lower Arroyo Park to Pasadena Roving Archers and other archers in a vote early in the morning of February 3, 2015. After a five hour public hearing and discussion, the council split 5-3.

The archers loudly proclaimed that the new agreement is not for "exclusive use" because anyone can still walk near the archery range, but in the future all other users will be warned by signs and barriers not to stray into the large archery range because in the judgment of the City Council it is too unsafe to allow the public to enjoy the area. All non-archers will be restricted to the dry, barren path lined by a chain link fence near the flood channel. No one, however, goes to the Lower Arroyo to walk near the flood channel.

As a conservation organization, ASF's vision is for a restored Arroyo Seco River flowing through a nature preservation area. Archers can fit into that vision, if proper safety restrictions are applied and if the public, at least at some times, has access to one of the most beautiful spots in the urban Arroyo Seco.

ASF urges you to visit the Steward's website for more details.

Here's Something Real You Can Do About the Drought - Click Here: