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.


Proposal to City Council of La Cañada by LA County Supervisor Michael Antonovich

NB: This is the intial memo in 2011 from LCF city officials on traffic concerns about the Hahamongna sediment removal program. Since then the number of trucks and the routing issues have increased substantially.

Upon request, Erik Zandvliet, the City Traffic Engineer, provided the minutes of the January 19, 2011 Special meeting of the La Cañada City Council.

Yesterday, the Council was informed about an upcoming County project to clear debris from the Hahamonga park basin, aka "Devil's Gate Reservoir".

Here is an excerpt of the project description given by LA County Flood Control District:

"Los Angeles County Flood Control District is currently working on a major sediment removal project from Devil's Gate Reservoir. Although the excavation site is in the City of Pasadena, we will need to utilize roads belonging to the City of La Cañada Flintridge to haul material to the disposal site in the Cities of Azusa and Irwindale. We are planning to haul a total of 1,671,000 CY (cubic yards) of post fire debris over a 3-year span. Work on this project is expected to begin September 2011. Subsequently excavation will begin as early as May and end as late as December of each year, weather permitting. Work will only ensue Monday-Friday from 7:30am to 5:00pm.

The inbound haul route will be coming northbound on the 210 and exiting at Berkshire Place, making a right onto Oak Grove Drive and then a left into the construction site. The outbound haul route will exit the construction site heading north on Oak Grove Drive, making a left on Berkshire Place and then another left onto the 210 southbound. Both inbound and outbound traffic will venture near the south end of La Cañada High School."

This translates to about 170,000 truck trips. The route would NOT go past the front of La Cañada High School. We have informed LAC-FCD that we are asking for the street pavement to be replaced at the end of the project, and that we would have to approve a hauling plan that avoids school times and JPL peak hours. They have agreed in principal to these conditions. We have also asked the County to consider splitting the trips onto other streets as well.