Recent Landslide Hazard Assessments

Landslide Watch

Post-Wildfire Watershed Emergency Response

California Watershed Emergency Response Teams (WERTs) help communities prepare after wildfire by rapidly documenting and communicating post-fire risks to life and property posed by debris flow, flood, and rock fall hazards. The WERT response is led by the California Department of Forestry and Fire Protection (CAL FIRE) and co-led by the California Geological Survey (Department of Conservation). To learn how the CGS works with CAL FIRE and others to analyze landslide potential on newly burned landscapes, visit the CalConservation blog: Notes from the Field.

Requests for WERT report information should be directed to CAL FIRE. (CAL FIRE by default provides WERT evaluation reports and maps to affected communities, flood control managers, and emergency managers.)

2022 WERT Response

Updated October 21, 2022

In 2022, CAL FIRE and the California Geological Survey deployed WERTs to the following major burns located in state responsibility areas:

Colorado Fire

Map of the burn area.

Fairview Fire

Map of the burn area.

McKinney Fire

Map of the burn area.

Mosquito Fire

Map of the burn area.

Mountain Fire

Map of the burn area.

Oak Fire

Map of the burn area.

2021 WERT Response

Updated October 21, 2022

Enhanced landslide hazards continue to exist in the 2021 wildfire areas. A typical watershed recovery period after fire is two to five years; but in some areas it can take up to ten years as trees die and roots decay. Please keep this in mind and plan accordingly.

Alisal Fire

Map of the burn area.

Caldor Fire

Map of the burn area.

Dixie Fire

Map of the burn area.

French Fire

Map of the burn area.

2020 WERT Response

Updated October 25, 2021

Enhanced landslide hazards continue to exist in the 2020 wildfire areas. A typical watershed recovery period after fire is two to five years; but in some areas it can take up to ten years as trees die and roots decay. Please keep this in mind and plan accordingly.

Apple and El Dorado Fires

Map of the burn area.

Blue Ridge Fire

Map of the burn area.

Bond and Silverado Fires

Map of the burn area.

Carmel Fire

Map of the burn area.

Creek Fire

Map of the burn area.

CZU Lightning Complex

Map of the burn area.

Glass Fire

Map of the burn area.

LNU Lightning Complex - Hennessy Fire

Map of the burn area.

LNU Lightning Complex - Walbridge and Meyers Fires

Map of the burn area.

North Complex

Map of the burn area.

River Fire

Map of the burn area.

SCU Lightning Complex

Map of the burn area.

Snow Fire

Map of the burn area.

Images from the Field

Select any photo to open it full size in a new window.

David Longstreth, senior engineering geologist in California Geological Survey’s (CGS) Forest and Watershed Geology program, is one of many in the field studying burn areas in the Santa Cruz area after the CZU Lightning Complex. He is determining risk communities can expect come rainy season:

Watershed Emergency Response Teams

California Watershed Emergency Response Teams (WERTs) help communities prepare after wildfire by rapidly documenting and communicating post-fire risks to life and property posed by debris flow, flood, and rock fall hazards. The WERT response is led by the California Department of Forestry and Fire Protection (CAL FIRE) and co-led by the California Geological Survey (Department of Conservation).

The WERT five-step process to risk reduction: 1. Determine soil burn severity. 2. Identify values at risk. 3. Identify, model, and classify hazards. 4. Develop emergency protective measure(s). 5. Communicate findings.WERT objectives are completed in a rapid step-wise manner to achieve the goal of risk reduction. A fundamental step in the WERT process is the identification and characterization of values-at-risk (VARs). VARs are the values or resources at risk of damage or loss by post-wildfire geologic and/or hydrologic hazards. The WERT process utilizes a qualitative approach to evaluate risk to these values, and relies on a combination of modeling and best professional judgment to guide relative risk determination and the development of emergency protection measures. The final step in risk reduction is to communicate the evaluation findings to local jurisdictions responsible for emergency planning and preparedness.

The decision to conduct a WERT response is made by CAL FIRE in coordination with local and federal agencies, and is also based on:

  • Fire size and intensity, and its location in relation to values-at-risk (VARs).
  • Proximity of intensely burned areas with steep slopes to housing developments.
  • Likelihood of debris flows based on topography, geology, climate, etc. impacting VARs.
  • Proximity of VARs to flood and debris flow prone areas affected by the fire.
  • Presence of transportation networks, water supply systems, campgrounds, etc. at potentially high risk.
  • Fire that includes a significant percentage of state responsibility areas.
Smoke column above the Lake Fire (2020). Photo credit: Austin Dave.
A large smoke column rises thousands of feet above chaparral-covered mountains.

Web page by:
California Regional Geologic and Landslide Mapping Program

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