Updated: County to Store Sediment in Hahamongna in Dam Clean-out Project

A county engineering project to remove 25,000 cubic feet of mud and debris stuck in the will use on-site storage in the Hahamongna Watershed Park, an option that will greatly reduce the number of dirt-hauling trucks on city streets.

The county's plans to clean out the dam took on a new urgency after the 2009 Station Fire caused a tremendous uptick in the amount of debris being washed into the dam the last two winters.

Ultimately the county will do a "big dig" that will result in up to 2 million cubic yards of dirt being removed from the dam.

The upcoming "little dig" of 25,000 cubic yards became an issue in May. County officials announced their would likely bypass hauling in front of , but would heavily use Windsor Avenue through Altadena. That could have meant dozens of trucks hauling dirt back and forth all day long for weeks or months on Windsor and smaller neighborhood streets.

With the new plan, the county will still need to haul out trees and some other debris on Altadena streets, but will be able to limit truck traffic to 10 loads a day, according to Kerjon Lee of the County Department of Public Works.

Officials also suggested an option to store most of the debris on site at a former sports field area called Johnson Field, a move that Pasadena city officials originally .

The Altadena Town Council , and the county agreed to do a to allay concerns about potential wildlife that could be disrupted at Johnson Field.

At Monday night's Pasadena City Council meeting the council voted unanimously to endorse the plan to do work at Johnson Field.

City Engineer Dan Rix said that a biologist will be working on site during the dig to make sure that nesting birds and toads that live in the area will not be impacted.

A recreational trail that will be used by trucks during the process will be rerouted so park users can continue to walk in the area, according to the Pasadena staff report.

The county had originally wanted to start the work in July, so it will likely begin soon.