With sufficient warning of a flood, a community and its floodplain occupants can take protective measures to mitigate potential damage. A flood threat recognition system integrated with an emergency response plan and a multi-level flood inundation map(s) enables emergency warning dissemination to the public and critical facilities. This is the basis of flood warning and response and is part of the emergency management preparedness cycle.
Flood inundation maps are integrated with the Flood Warning System and the Flood Response Plan. For areas of the Special Flood Hazard Area along major rivers and streams that are affected by broad floodplains and/or upland flooding, these watercourses will have five inundation levels for the (i) Bankfull and Below, (ii) Action, (iii) Flood, (iv) Moderate Flood, and (v) Major Flood levels. These levels are attached to observed stream gages operated by Ventura County Watershed Protection District (VCWPD), the United Stage Geological Survey (USGS), and the California Department of Water Resources (CDWR) and/or critical forecast locations and can be turned on in the online Response Plan to show the specific inundation area along with specific impact locations. The inundation levels for coastal areas use existing Coastal High Hazard (VE) Zone inundation and the tsunami inundation areas.
Ventura County Watershed Protection District operates and maintains the infrastructure for the Flood Warning System Program. The actual implementation of emergency procedures for facilities not owned by VCWPD and for private property is handled by the Sheriff’s Office of Emergency Services (VCOES) for unincorporated Ventura County. VCOES also acts as the focal point for all 10 cities in Ventura County for flooding within the cities and handles all communication between the Sheriff’s Emergency Operations Center and each cities’ individual Emergency Operations Centers. Flood Warnings are issued by the National Weather Service in Oxnard. VCWPD coordinates with the NWS during storms to make sure that NWS decisions are determined using the most accurate data possible. VCWPD also provides knowledge of the responses of individual tributaries and if flooding conditions are, or could occur, on channels that are currently not modeled by the NWS. Sheriff’s OES coordinates any evacuations with local police and fire officials. VCWPD Storm Operations Center provides the intelligence and planning information so action plans and priorities can be set by emergency managers. The full benefit of early flood warning is only realized if warnings are disseminated to the general public and critical facilities and has a flood warning and response plan that includes appropriate tasks, such as directing evacuation, sandbagging, and/or moving building contents above flood levels.