COMMUNITY OF LA CONCHITA
The storms impacting Ventura County January 9-10, 2023, delivered substantial rainfall, resulting in localized flooding, debris flows, and road closures throughout the county. It also reached historic triggers for debris flow and land movement in the area of La Conchita. Upon reaching the historical threshold of 8 inches of rain in 14 days, surficial failures of the hillside occurred and prompted an evacuation of the community on 1/9/2023. As rainfall subsided on 1/10/2023, County personnel evaluated the hillside and no signs of imminent failure were observed. The evacuation order was subsequently lifted at 6:00 PM. The decision to lift the evacuation order for the Community of La Conchita should not be construed that the area has been deemed safe and/or free of geological hazards. The hillside remains susceptible to debris flows and landslides.
The Community of La Conchita has been deemed a geologic hazard area by the County of Ventura. County officials advise against entry into the area under any circumstance.
Based on the present information known about ancient landslides and the 1995 and 2005 landslides, the following geologic hazards are present:
- Catastrophic Failure: The large ancient landslide mass located above the community could potentially fall, impacting residences within the community at any time, without warning.
- Mudflows: Mudflows could potentially impact all residences and access roads within the community.
- Catastrophic failure and mudslides: Should both event occur simultaneously, the community could be impacted.
- No excavation (removal of earth material) or grading should be performed in the community without recommendations from a geologist and/or geotechnical engineer and review by the County of Ventura Public Works Agency.
Emergency Alerts / Notifications
- Due to the complex nature of the geologic hazards at La Conchita, local public safety personnel have no way to predict if and when a failure of the hillside may occur. Because of this, residents should not wait for local authorities to issue evacuation warnings or orders before leaving the area. Alternatively, it is advisable that residents monitor weather forecasts, rainfall rates and present conditions of the hillside to gauge the need to evacuate. If an obvious failure of the hillside is occurring or about to occur, the Ventura County Sheriff’s Office of Emergency Services will issue an alert to residents, however it may be too late depending on circumstances.
- It is incumbent upon residents that choose to live in the area to exercise due diligence in monitoring the condition of the hillside and taking early action to evacuate during periods of increased danger.
La Conchita Historical Event Triggers
The following historical triggers were encountered in La Conchita and help to serve as indicators for a potential geological event:
- 15″ of rainfall in 30 days or less
- The 1995 La Conchita Landslide occurred two months after the area received approximately 15″ of rainfall over a 30 day period. Ground cracks, bulging and sloughing at the toe of the slope were also observed several months prior to this failure.
- 8″ of rainfall in any two-week period
- The 2005 landslide occurred at the culmination of a wet 2-week period of rainfall where approximately 8″ of rain fell.
- 1″ of rainfall per hour or greater carriers the potential to trigger flooding, landslides or debris flows at any location.
- A small landslide impacted on property in December 2010 following a storm that produced rain at a rate of 1″ per hour.
Weather Forecast Resources & Live Radar Feeds
Recent Rainfall (in inches)
LA CONCHITA BLUFF
14 – Day Total
28 – Day Total
24 – Hour Total
Peak 1 – Hour Intensity