Contra Costa County Fire briefs Lafayette on updated hazard maps, evacuation planning and new detection tools

Contra Costa County Fire officials told the Lafayette City Council on March 24 that updated wildfire hazard maps released by Cal Fire and new modeling tools should change how local mitigation work is prioritized.

Assistant Chief (Contra Costa County Fire) summarized the county’s 2024 accomplishments, local call volume and how the department is preparing for fire season, and he outlined public steps residents should take now, including signing up for the county Community Warning System (CWS) and knowing their evacuation zone via the Genesis platform.

The presentation included three points city officials said matter most: (1) the state’s 2025 wildfire-hazard-severity maps now show very high, high and moderate classifications and cities must adopt map layers for local responsibility areas; (2) the county uses finer-grain fuel and flame-length models, plus structure-risk analysis, to prioritize mitigation projects beyond the map categories; and (3) new technology—ember-casting progression models and expanded aerial and camera detection systems—are being used to forecast fire spread and improve early response.

Why it matters: Lafayette residents face a mix of very high, high and moderate-rated areas under the 2025 maps. County officials said the updated maps change which neighborhoods will be eligible for some county mitigation work and grant programs, and urged residents to confirm their zone and defensible-space obligations.

Key details and follow-up actions - The assistant chief said Lafayette apparatus ran about 2,195 calls in 2024 with medical calls and vehicle collisions the largest categories; the first two months of 2025 totaled 334 calls and call volumes are “on track” with last year. - On the map changes, the presenter noted that Lafayette had about 4,440 acres previously listed as very high in the 2011 adopted maps; under the 2025 mapping there are 41 acres in the “very high” class, 5,309 acres now listed as high and 1,668 acres listed as moderate in Lafayette. He advised residents to use the county’s interactive before/after swipe tool to review neighborhood-level changes. - The county is asking for public comments before the local ordinance adopting the updated maps; a public meeting was scheduled for April 1 at 6 p.m. in Martinez (Board of Supervisors chambers) with hybrid attendance and a recorded public-comment option. - County mitigation decisions are not made solely on the severity map label; staff said they also review 5-meter fuel-resolution models that estimate predicted flame length, ladder fuels and slope to pick fuel-break and evacuation-route cleanup locations. - On proposed “Zone 0” regulation (defensible-space rules closest to structures), the county said the draft Board of Forestry standards circulated in March would likely require new-construction rules to begin on a future date and may apply differently in State Responsibility Areas (SRA) versus Local Responsibility Areas (LRA). The draft at that time suggested zone-0 rules apply to all three severity classes in SRA but only to very high in LRA; the Board of Forestry workshops were continuing and public comment was open. - The county described new modeling and detection tools—ember-cast progression models and AlertCalifornia wildfire cameras with emerging AI detection—as improving early detection and situational awareness; the presenter said the county validated model outputs on known past fires.

Resident questions and concerns Residents asked about the new map numbers and how they were derived; one speaker said the acreage changes seemed confusing and asked for clarity on which areas grew or shrank in each category. County staff agreed to request and post the underlying moderate/high acreage breakdown used to make the maps.

A resident asked about the consequences for residents whose rating decreased; the county reiterated that mitigation prioritization uses multiple layers of data, not just the map label, and that grant eligibility and mitigation projects are considered using those finer-grain fuel and risk models.

Council discussion focused on public outreach and coordination. Council members and staff said they would ensure the city posts explanatory information and a link to the county’s interactive map and comment portal, and urged residents to sign up for CWS.

Ending County staff encouraged Lafayette residents to sign up for emergency alerts, prepare a “go bag,” review defensible-space guidance and attend the April 1 public meeting to submit comments on the revised hazard maps. The county said it will continue outreach on evacuation-route cleanups, Firewise community support and other local mitigation activities.