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.


Witness the Winter Storms in Hahamongna

Winter Storms

Is this anyplace to put soccer fields?


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.


Tree Dumping in Hahamongna

February 9, 2011 - Tree dumping has returned to Hahamongna again despite a long history of community concern about what uses are appropriate in this environmentally sensitive area. After the recent winter storms, City of Pasadena crews have dumped massive logs from fallen trees just east of the parking lot at Hahamongna.

This is the site of the former Boersma soil amendment business that operated for more than four decades in Hahamongna. Boersma mixed sand and gravel with horse manure, which they stored in massive piles near the stream zone, and sold it as a soil amendment for local gardeners and landscappers. Community pressure led to the ouster of Boersma in 1994, but the effects of their trucks and equipment still remain. The soil in the area is heavily-compacted and patches of asphalt strew the area. This degraded condition prevents healthy habitat from growing there.

Pasadena made a commitment in the mid-90s to upgrade the habitat there when they booted Boersma and several other gravel and heavy equipment operators from Hahamongna. They even obtained grant funds from the County Parks Bond Measures in 1992 and and 1996 ($2.86 million) to do that. Regretably Pasadena has not moved forward with any significant habitat restoration in the area. Instead the city intends to use the County bond funds to build a new massive soccer field and parking lot in the middle of the flood basin. They are even using their neglect of the area as part of the justification for the parking lot and soccer field, stating that the area is degraded and "ruderal".

What a sad statement about Pasadena's commitment to environmental stewardship.

What to do something about it?
Send a message to Pasadena City Manager Michael Beck. Click Here

Photo credit: M. Gaede