Meetings Next Week to Discuss Pacoima Dam Sediment Project

Residents are expected to voice concern about a project they say could create significant traffic and health issues.

The Los Angeles County Department of Public Works (DPW) is proposing to remove millions of cubic feet of sediment from the Pacoima Reservoir in order to restore flood control and water conservation capacity at the site.

But area residents are worried about potentially hundreds of dump trucks going in and out of the reservoir hauling sediment, with the potential for dust and particles to spread in the area.

A series of meetings — beginning Wednesday, March 25, at Los Angeles Mission College in Sylmar — are planned to give residents and others a chance to speak directly to the project officials. 

“The primary concern is what’s carried in the wind. After the Station Fire, when the winds swept up they sent black soot [into the air]. That’s the concern because we have a high wind area. The soil that they’re going to stir up with the massive dig and load project could bring health issues like valley fever and asthma,” said Dan Feinberg, president of the nonprofit group Citizens Against Strip Mining (CASM).

“And we’re going to have a huge amount of trucking on the 405 Freeway and Foothill Boulevard,” Feinberg added.

The DPW proposal calls for the sediment to be taken to pits in Sun Valley and the Sunshine Canyon Landfill. The project would begin in 2017 after a two-year process that seeks community input before a final plan is submitted to the Board of Supervisors, which ultimately decides on the project.

After the 2009 Station Fire and the 2008 Sayre and Marek Fires, according to DPW, storms washed abnormally large volumes of sediment into the reservoir that decreased its storage capacity and increased the chances of plugging the outlet works with sediment or debris.

DPW Spokesman Christopher Stone said those fires destroyed 80 percent of the reservoir’s watershed, leading to a “huge amount of sediment flow into the reservoir because of the burned vegetation.”

Adverse Effects

In its current condition, Stone said, the reservoir does not have sufficient capacity to contain a large debris event without burying the outlet works. The lowest outlet gate, which is normally used to naturally pass sediment through the dam, is buried under 65 feet of sediment. An additional 31 feet of sediment on the upstream face of the dam would bury the inlets for all other flood outlet valves, making them inoperable.

Stone said that if this trend continues unabated, it would adversely affect the reservoir’s operation, blocking the valves to release water and limiting the amount of water that it can store.

 Right now the proposal calls for the removal of 3 million cubic yards of sediment, but that could increase by the time the project gets underway and is finalized. 

It could take between five and seven years for the actual removal process to be completed.

That length of time is due in part by the amount of sediment to be removed and the fact that this can only be done during the summer months, Stone said.

The trucks would be in operation from May through November. The rest of the year has to be devoted to flood control at the reservoir, he noted.

The Pacoima Reservoir was built in 1929 and has been cleaned out seven times. The last time was in 1983, when more than one million cubic yards of sediments were removed — the biggest project yet.

Feinberg said this time it’s much bigger than that.

He estimates that at 10 cubic yards for each dump truck, the project would entail potentially 500,000 dump trucks driving each way.

He said his organization has proposed an alternate route and site for the sediment removal, going to the back side of the reservoir in the National Forest, but DPW has opted for the other route. CASM also asked for DPW to use natural gas dump trucks. So far, the agency has not agreed to this.

Public Meetings

Feinberg hopes people attend  the community meetings to learn more about the project and speak out.

“Once they talk to the community, the community may be very upset and they can change or modify the project. When the dump trucks start rolling it’s too late to do anything about it,” Feinberg said.

And this is a problem the communities will face again, Feinberg contends.

“This problem never goes away. Over time the sediment will build again and they’re going to come back and do it again. They neglected the process and they’ll neglect it again,” he said.

Kerjon Lee, DPW spokesman, noted “there will be concerns, dust or noise” with any project of this size and these scoping meetings will allow people to express  “whatever issues that may need to be addressed by the department.”

“Our roles as the engineers for the flood control district is to review the amount of rain and sediment in the reservoir and make an assessment based on science,” Lee said.

“We may recommend to take out only half of the sediment proposed. Their (community) feedback would be used to draft the proposal brought to the Board of Supervisors.”

The project meetings will be held on the following dates: