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.

HWPAC Resolution on County Sediment Removal Program

At their meeting of November 30, 2010, the Hahamongna Watershed Park Advisory Committee Committee passed a formal motion which included the following items:

  • Committee notification of when the project comes before the County Board of Supervisors
  • Posting of the County's project presentation on the Pasadena city website
  • Strong support for jobs for local residents, especially women and minorities
  • Request that the County study alternatives which would have less impact upon the natural habitat and which would cause less noise, air pollution and traffic impact
  • Request that the County study the maintenance road in terms of its surface, permanent nature, and width
  • Request that the County seek opportunities to reduce the impacts of the project upon park users
  • Regular quarterly updates to the Committee about the project from city staff and a presentation by County staff after they have their permits from the regulatory agencies.