Hahamongna is that 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.

Threats to Hahamongna

It's the most precious enviromental zone in our region, but it's under attack again.

A massive sediment and habitat removal program of the County of Los Angeles threatens to strip the basin of its rare riparian and alluvial scrub habitat

The Sustainable Plan for Hahamongna

Dangers of Diesel


A Strategy to Save Hahamongna


Hahamongna Updates

Corps Responds: Don't Bother Us

The US Army Corps of Engineers, among its other responsibilities, is charged with protecting the precious wetlands and streamzones in the United States, including Hahamongna. Recently the Corps issued a public notice regarding their permit for the Devil's Gate Sediment Mining and Trucking program, aka the Big Dig, and gave the public the opportunity to comment on the notice. Dozens of people and agencies responded with thoughtful commments. Most requested that the Corps conduct a public hearing to discuss their responsibilities.

David J. Castaron. the Chief of the Regulatory Division, Los Angeles District, U.S. Army Corps of EngineersCorps Regulatory Division has now officially responded with a generic letter to "Public Notice Comenters." "The issues you raised are similar to these other written comments we received for the proposed project. Considering the above opportunities the public has had to submit comments to the Corps, it is unlikely any new information would be disclosed as the result of a public hearing."

He continues: "After careful consideration of your request pursuant to Corps regulations at 33 CFR Part 327, we have determined that a public hearing is not warranted at this time."

Can you hear the County's bulldozers reving up their engines?