Arroyo Seco Foundation  
Here's the Latest for All Things Arroyo —

This year marks the 25 anniversary of Hahamongna Watershed Park, so it's time to look back on the history of the park and the meaning of Hahamongns.

Come Visit Hahamongna ASAP!

Alternate Visions

The bulldozers and trucks are lined up ready to destroy the most precious habitat and wildlife corriror in the west San Gabriel Valley.

Trout Scouting in the Arroyo

Fisheries biologist Ken Jarrett from Stillwater Sciences took a crew of ASF volunteers up the canyon to assess conditions for native fish.

Brown Canyon Dam — Then and Now

Paul Ayers unearthed these pictures of Brown Canyon Dam three and a half miles up the Arroyo Seco Canyon from the mouth of the Arroyo near JPL.

Pasadena's Urban Forestry Advisory Commission voted 3-2 to spare the eight mature oak trees that the Pasadena Casting Club wanted to turn into sawdust thanks to strong opposition form neighbors and Arroyo-lovers. But the casters haven't given up, so keep on the alert for future attempts to degrade the Lower Arroyo.

Concerns about "One Arroyo" Dominate Quarterly Meeting

Credit: Pasadena Now

There was a fascinating presentation and a lively discussion about the future of the Arroyo Seco after "One Arroyo" at the Pasadena Public Library in April.

Big Push to Include Arroyo in LA River Planning

"It's like an arm on a body," Tim Brick explains on KABC-TV.

Senator Portantino Moves to Include the Arroyo

Senator Anthony Portantino has introduced legislation to add representation for the Arroyo Seco in the Upper LA River and Tributaries Working Group.

Protecting Hahamongna: Big Dig Update

ASF and Pasadena Audubon are still working with Supervisor Barger and the County Department of Public Works to reduce the impacts of the Flood Control District's sediment removal program at Devil's Gate Dam. In November Supervisor Barger push through a motion to scale back the program in November. That was a big step, but there are still some unresolved problems with the Big Dig. We hope to have more news about the future of Hahamongna for you soon.

Help Grow

Would you like to be part of the Hahamongna Nursery Team? You can learn about native plant identification and how to propagate and tend California's most venerable and spectacular plants. They are a precious legacy for future generations. Send an email to


The battle to Save Hahamongna has been a long and bitterly fought one. Click on the link below to review the updates on the campaign against the Big Dig and witness citizen power in action.

Thank you for your support and congratulations!

Native Fish in the Arroyo — Can We Bring Them Back?

The answer, of course, is Yes! While there are numerous barriers and problems, the conditions in many parts of the Arroyo watershed are excellent for native fish including Rainbow Trout and Steelhead. ASF's meeting last July at the Pasadena Public Library generated a lot of interest and discussion about native fish.


One Arroyo

The Arroyo Advisory Group reported their progress to the Pasadena City Council on February 5th. The City Council approved $100,000 to establish a foundation that will raise funds for Arroyo Projects, such as a major trail improvement that will provide greater access and link together he various parts of the Arroyo in Pasadena.

Want to see a beautiful native plant garden? Check out the one this crew planted at Linda Vista Library, 281 Bryant St, Pasadena, CA 91103.

Arroyo River Parks
Restoring a Living River

Here's an innovative approach for the future that will restore the Arroyo Seco by integrating the river into the parks and the parks into the river.

Why Not a Complete San Gabriel Mountains National Monument?

Now that the Trump Administration review of National Monuments seems to be winding down, it's time to again raise an issue about our local 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 when the San Gabriel Mountains National Monument was announced. It's a shame because many of the most treasured and historic sites in the San Gabriel Mountains are contained in the territory that was not included.

Congresswoman Judy Chu has now proposed legislation that would expand the boundaries of the national monument to include all of the treasures of the Angeles National Forest.


Arroyo 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. As the result of a legal challenge, the project is now undergoing further environmental review.