California’s largest watershed protection mission in the hurricane-force firestorm’s burn scars is underway, with more than 400 personnel mobilized through the California Governor’s Office of Emergency Services (Cal OES).
Ash and debris from structures burned in wildfires contain toxic materials, making watershed protection a critical effort to prevent contamination of streams and waterways.
Local agencies, environmental experts, engineers, and emergency management teams work together to develop mitigation plans tailored to the terrain, burn severity, and proximity to water sources.
Cal OES is partnering with Cal Fire, California Conservation Corps (CCC), California Department of Water Resources (CDWR), Caltrans and California Department of Conservation Geological Survey, to protect waterways from toxic runoff.
Three separate missions are being conducted by the Cal OES watershed and Debris Flow Force:
Watershed Protection Mission: Cal OES has mission tasked the CCC to use emergency protection materials to contain hazardous materials from the Eaton and Palisades Fire from entering LA’s creeks, rivers and other bodies of water. CDWR and Caltrans are also partners on this mission.
Debris Flow Mitigation Mission: Local jurisdictions and public works have asked Cal OES to secure materials like K-Rails to divert debris flow runoff. Cal OES is coordinating materials requested by local jurisdictions.
Debris Basin Mission: Cal OES has mission tasked the California Military Department (California National Guard) to conduct debris basin cleanup activities.
What materials are used for this work?
The CCC and other partners will use a variety of Emergency Protection Materials (EPMs) to prevent toxic materials contaminating waterways. Containing runoff effectively protects aquatic ecosystems, sensitive habits and recreational areas and prevents long-term ecological and economic damage.
They include:
Compost Socks are a type of contained compost filter berm. The sock is usually a mesh tube filled with composted material that acts like a strainer. It controls erosion, while capturing sediment and other pollutants in it, while letting clean water to flow through it. These are used for the Watershed Protection Mission.
Straw wattles are burlap tubes of compressed straw that provide perimeter protection at base slopes, inlets and roadways. They reduce soil erosion and runoff while retaining sediment. Straw wattles are also used to intercept water running down a slope. They can be used over bare soil or in with erosion control blankets, on steep slopes, around drains for inlet protection, or as a perimeter control for job sites. Straw wattles are weed-free and help stabilize slopes by slowing, spreading, and filtering overland water flow. They are flexible and conform to the soil surface. These are used for the Watershed Protection Mission.
K-Rails are concrete barrier used to divert debris flow away from life and property. This is used for Debris Flow Mitigation mission.
Other EPMS:
Silt Fences, which are made of a filter fabric that’s been entrenched, attached to supporting poles, and sometimes backed by a plastic or wire mesh for support. The silt fence captures sediment-laden water. None have been requested.
Muscle Wall: A large hard plastic barrier diverts debris flow away from life and property. None have been requested.
Crews working in both the Palisades and Eaton areas have installed compost socks and straw wattles in residential neighborhoods.