Hahamongna is the rare spot in the Arroyo Seco at the foot of the San Gabriel Mountains where the mountainous watershed meets the urban plain. Periodically floods roar into this basin. Bounded on the north by the mountains and Jet Propulsion Laboratory and on the south by Devil's Gate Dam, Hahamongna contains five unique habitat zones that only exist in alluvial canyons near the mountains. Most sites like this in Southern California have been destroyed.

Don't let Hahamongna go the way of other lost environmental treasures in Southern California.

The Meaning of Hahamongna

The original settlers of the region were sometimes called the Hahamongna Indians. The word means "Flowing Waters, Fruitful Valley" in the native Tongva language.

The Public Speaks

On July 12, 2010 more than forty speakers came forward to address the Pasadena City Council on the subject of athletic fields and other inappropriate intrusions on the natural character of Hahamongna, our region's most precious natural treasure. Not one speaker advocated soccer fields. At the end of the discussion the City Council eliminated one proposed soccer field from the Hahamongna Master Plan, but deadlocked 4-4 on a motion to eliminate the other remaining athletic field. This field and the related parking lot and filling of twenty-seven acres of streamzone is the subject of the current Environmental Impact Report.

You can view the dramatic and eloquent statements of local residents at the site below. Go to item 11 on the agenda.

Hahamongna: Keep It Natural



Hahamongna Multi-Benefit - Multi-Use Project
EIR Toolkit


PUBLIC REVIEW PERIOD: The comment period for the scope of the EIR closed on August 23, 2012.

View Some of the Comments Submitted to the Right

The Hahamongna Multi-Benefit Project is a program proposed by the City of Pasadena to implement parts of the Arroyo Seco Master Plan approved by the Pasadena City Council in 2003. It is comprised of three projects:

  • Sycamore Grove Athletic Field: This project will create a new athletic field and expand the current parking lot in Hahamongna Watershed Park. Twenty-seven acres in the middle of the Hahamongna basin will be filled in, compacted and elevated to place the athletic field and parking lot above the area that floods frequently. The project will also include relocating the current disc golf course onto the twenty-acre elevated pad and the expansion of the current parking lot from 100 to 200 parking spaces along with various storm drain improvements.

  • Westside Perimeter Trail: This project will improve 1,900 linear feet of trail, from the recently completed Flint Wash Bridge Trail Crossing to the proposed Sycamore Grove Field. The project will include a combination of historic trail restoration, trail realignment, installation of a 40 foot bridge crossing over Berkshire Creek and raising a portion of the trail above its current elevation so that it is above the level of frequent flooding for hikers and equestrians.

  • Restoration of Berkshire Creek: This project will restore a small canyon on the west of Hahamongna Watershed Park and reestablish the stream course that has been severely degraded by the high urban storm water flows through this canyon. The project will improve water quality by eliminating the large volume of trash that empties into this canyon and further into the Hahamongna basin and will also restore habitat. A portion of this project will be completed under the Multi-Benefit project.

    • Here you will find tools to give your information and background to help you prepare your comments for the Hahamongna Multi-Benefit Environmental Impact Report. We will be adding additional material, so check back regularly for new resources and to view the public comments.

    Why Is Hahamongna So Special?

    City of Pasadena Environmental and Planning Documents

    Ecosystem Assessments of Hahamongna Watershed Park

    The California Environmental Quality Act