California Flood Preparedness



According to the California Department of Water Resources, catastrophic flooding can happen even in the middle of a drought, so we must "be aware, be prepared, and take action"! Prepare your family and property for flooding, and find out what to do during a flood.

Know Your Flood Hazard
Insure Your Property
Protect People from the Hazard
Protect Your Community from the Hazard
Build Responsibly
Protect Natural Floodplain Function

For additional information on floods, please visit our Flood Control District's "Flood Preparedness" page.

Alhambra Creek Flooding 1950-19512
(Alhambra Creek Flooding, 1950-1951)

​Know Your Flood Hazard


Your property is subject to flooding and FEMA has created flood hazard maps to show different degrees of risk of flooding by outlining different flood risk areas. Visit the FEMA Map Service Center to find flood hazard information; you can enter your address directly.

Public Works staff can determine your flood zone determination using available Assessor's Parcel Map, County base maps, FEMA information, and other documents or maps. The fee for this written determination is $50 per parcel. If a site visit is warranted, there will be an additional $250 fee.

See below for additional information on knowing your flood risk:
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Insure Your Property

Your standard homeowners' insurance does not cover flood damage. You can lessen the financial consequences of a flood by obtaining flood insurance. Find an insurance agent near you through FloodSmart.gov (National Flood Insurance Program).

See below for additional information on flood insurance:
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Protect People from the Hazard

Stay Out, Stay Alive!
Flood control channels are part of our community's infrastructure. They are designed to drain stormwater from our communities swiftly to prevent flooding, and should not be used for recreation. Be aware of fast-moving stormwaters in our channels and creeks.
                                  Stay Out, Stay Alive

Visit the Contra Costa County Flood Control and Water Conservation District's webpage on the Creek and Channel Safety Awareness Program for additional information.

Know Your Flood Warning Signs
If flooding occurs, the County will warn residents through radio, TV announcements, and emergency officials and vehicles. Please know the flood warning procedures and plan escapes to higher ground.

The Office of Emergency Services has useful information, such as the Local Multi-Jurisdictional Local Hazard Mitigation Plan, Emergency Operations Plan, and Community Warning System.

See below for additional information on protecting yourself and your family from flood hazards:
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Protect Your Property

Along with preparing yourself and your family for a flood, safeguard your property (e.g., home, business, and possessions). Keep debris and trash out of streams, ditches, and drain inlets. These convey stormwater from our community to the bay, delta, and sea. There are flood-proofing improvements that can be done to your structure that may reduce damage caused by flooding. Consider elevating the building using flood-resistant materials, or performing simpler improvements, such as replacing your flooded furnace with one elevated above the flood level.

See below for additional information on ways to protect your property:
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Build Responsibly

Get a building permit from our Application and Permit Center before your build. A Floodplain Permit is required if you are constructing within the FEMA designated SFHA. Improvements within the floodplain has the potential to impact flood levels, your property, and your structure.

For new and redeveloped development, Provision C.3 of our Municipal Regional Permit (MRP) requires the site design to minimize the impervious surface areas and encourages pervious surfaces where feasible for infiltration to underlying soil. Runoff from impervious surface areas must be captured and treated before discharging. The Stormwater C.3 Guidebook will assist applicants through the process of submittals and review. Visit the County Watershed Program and the Contra Costa County Clean Water websites for additional information.

See below for additional information on building responsibly:

Protect Natural Floodplain Functions


Don't dump in the storm drains; they drain to our bay or delta. Ensure that RAIN [GOES] DOWN the DRAIN.

The storm drain inlets do not route water to a treatment facility. Stormwater flow untreated to the bay or delta. If you need to place storm drain markers on your drain inlet to remind people of this fact, makers are sold at the Public Works Department located at 255 Glacier Drive in Martinez.

                                        Storm drain marker_1

Visit or contact our County Watershed Program for more information on compliance with our National Pollutant Discharge Elimination System (NPDES) Municipal Regional Permit (MRP).

Natural floodplains are resources that may contain rare and endangered plants and animals, and they are of historical significance, as well. See below for additional information on natural floodplains and our watershed (County's public education and outreach information).