New Hahamongna Route Option Would Drastically Cut Truck Traffic

An option to store mud and debris from the Devil's Gate Dam clean-out project could almost completely eliminate heavy truck traffic on Altadena streets that would otherwise likely happen this summer.

The truck traffic would be the result of a plan to clear out 25,000 cubic yards of debris in the dam this summer to help clear it out and prevent it from overflowing in future winter storms. The County Department of Public Works has been planning the work for this summer with proposed street routes in Altadena and La Cañada Flintridge for trucks when they are en route to the 210 Freeway.

But at a , county officials presented a new option that would involve storing most of the debris in a ground basin with the Hahamongna Watershed Park (that option is outlined in green in the map on right).  That would involve an almost complete reduction of truck traffic, according to Bob Spencer, a department spokesman.

The trucks would still be on the streets for minimal hauling of non-organic garbage and boulders, but the vast majority of the dam's contents is dirt that would be stored on site under that plan, Spencer said.

The trade-off is that the dirt would likely have to be removed from the site at a later date when the department carries out its full task of removing the almost 2 million cubic yards of dirt that are in the dam site. That full project will require an environmental impact review as it would involve removal of dozens of acres of trees in the Hahamongna park.

Spencer said that if the department decides to store the debris on site it's unclear when or if it will be removed: that would be decided as part of the department's long term removal plan.

He noted that at last week's meeting there was some opposition to that storage plan because of concerns that the dirt would be stored on site to be used to build soccer fields in Hahamongna, a Pasadena city plan that local environmentalists have .

At the meeting, department officials recommended the storage plan, but also said that when dirt is ultimately removed, they'd recommend the Altadena route rather than the La Cañada Flintridge one.

That would involve trucks traveling up through Jet Propulsion Laboratory parking, then onto the streets starting at the intersection of Windsor and Ventura in Altadena. The trucks would then travel up and down Windsor to the 210 Freeway. 

Altadena residents at the meeting voiced strong opposition to that plan, and it could have a huge impact in the long run.  For the full plan of removing the 2 million cubic yards, the project could require 300 to 400 truckloads of dirt being removed on a daily basis for 9 months of the year for three to four years, according to the county's preliminary planning documents.

Redmond Carolipio contributed to the reporting in this story