Corps’ LA District removes 128 tons of floatable debris from San Gabriel Riverbed during weeklong cleanup project

AZUSA, California – The U.S. Army Corps of Engineers Los Angeles District removed 128 tons of floatable debris during a cleanup of the San Gabriel River, Feb. 22-28, 2022, near Azusa. The weeklong project filled 16 40-cubic-yard dumpsters with debris that can create runoff blockage during heavy rains and cause flooding of heavily populated areas downstream.

“The floatable debris consisted of remnants of abandoned camps left behind, which can pose a serious blockage in trash racks during rain events,” said Trevor Snyder, project manager with the LA District’s Operations and Maintenance Division. “The debris washes downstream into the dams and channels, thus reducing the flood-risk management capacity of the San Gabriel River.”

The work was done by hand, so as not to disturb bird nesting and other wildlife habitats, with debris gathered directly to dumpsters or at collection points along a hardtop pedestrian/bicycle path. A light, intermittent rain created a challenging working environment, with workers scouring the riverbed between the path and the San Gabriel Mountains, carrying soggy debris through heavy vegetation, before climbing a steep concrete embankment.

Piles of dumped trash littered the area. A recurring example of debris found in the area was a large amount of Arundo Donax, or giant reed, an invasive grass that resembles bamboo and is often used to construct encampment walls and huts. Workers also removed wood pallets, empty propane and gas cans, old tires, furniture, tarps, water cans and electronics, and even a rain-damaged, vintage arcade game that had long seen its last quarter. A total of 60 acres of riverbed was cleaned up by a crew of 15 contracted personnel, supported by two of the Corps’ LA District park rangers and a team of Azusa police officers.

“We also had interagency support from the City of Duarte, Irwindale Police Department, Los Angeles County Department of Health, Los Angeles County Department of Animal Control and the Los Angeles Homeless Services Authority,” Snyder said.

Camping in the San Gabriel River is illegal and inherently dangerous, as flash flooding can occur from heavy rains further upstream. As with previous riverbed cleanups, the Los Angeles Homeless Services Authority and Veterans Affairs supported the project with outreach events to assist any unhoused individuals within the 60-acre area prior to the cleanup.

“It is our hope that through collaborative outreach with our stakeholder partners, such as LAHSA and the VA, we can elevate those individuals experiencing homelessness out of the riverbed and connect them with services to improve their lives and improve the communities that we serve,” Snyder said.

CORPS’ HISTORY WITH THE SAN GABRIEL RIVER

Two adjacent sections of the San Gabriel River managed by the LA District also were cleaned recently.

The Corps maintains more than 50 miles of channels and levees within the San Gabriel, Los Angeles and Rio Hondo rivers, and Compton and Ballona creeks. Flood events that occurred between 1914 and 1934 were some of the most economically devastating floods the Los Angeles area historically experienced.

The Flood Control Act of 1936 (Pub. L. No. 74-738, § 5 (1936)) authorized Federal civil works flood-risk management projects for Los Angeles County, California. The Act authorized construction of flood-control structures for the Los Angeles County Drainage Area and the improvement of the San Gabriel River for the protection of metropolitan Los Angeles County.