Natural hazards · Castro Valley

Castro Valley, CA natural hazards

Most of the natural-hazard damage FEMA expects in Castro Valley comes from earthquakes, and overall the risk is very high for a U.S. community. Flood insurance has paid 17 claims here since 1978. 1 federal disaster brought FEMA money into town.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is Castro Valley?

Very high

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Castro Valley to be higher than in 87% of U.S. communities, mostly from earthquakes and inland flooding.

Earthquakes67%Inland flooding30%Everything else3%

By hazard

What Castro Valley faces

Each hazard’s share of the damage FEMA expects here, and how that compares with the rest of the country.

Earthquakes

67% of expected damage

Well above average · higher than 96% of U.S. places

Inland flooding

30% of expected damage

Above average · higher than 73% of U.S. places

Recorded about 2 times a year in the area

Lower here

TornadoesHailWinter weatherHeat wavesWildfireLandslidesStrong windLightningVolcanic activity

Not a risk here

Coastal floodingHurricanesIce stormsCold wavesDroughtAvalanchesTsunamis

Flood risk changes street by street. Check a specific address on FEMA’s flood map, and ask about flood insurance before you buy.

Flood insurance claims

Does Castro Valley flood?

Every paid claim on a federal flood insurance policy in Castro Valley, from FEMA’s records.

17paid claims since 1978

$538Kpaid to owners

0homes flooded more than once

19782026

Biggest named events

California Atmospheric River: 7 claims, $247K
Pineapple Express - Southern: 6 claims, $280K
Winter storm: 1 claim, $709

of homes in flood zones
are insured

of all homes
are insured

No community discount. Castro Valley isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Alameda County.

Disasters that hit Castro Valley

1 federal disaster brought FEMA money here

Disasters the President declared that paid out in Castro Valley itself: aid to households, or repair grants to Castro Valley.

Brought FEMA money into Castro ValleyDeclared for Alameda County only

2022

Severe Winter Storms, Flooding, Landslides, and Mudslides

175 households applied for aid $845K aid approved

Alameda County has had 20 natural disasters declared since 1953, most often severe storms and floods.

Around Castro Valley

Castro Valley and the towns around it

Very lowLowModerateHighVery high

San Leandromostly earthquakesVery high

Oaklandmostly earthquakesVery high

Haywardmostly earthquakesVery high

Ashlandmostly earthquakesVery high

Castro Valleymostly earthquakesVery high

Fairviewmostly earthquakesVery high

About these numbers

How to read this page

An average, not a forecastFEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.

Compared by rate“Higher than N%” compares yearly damage as a share of what’s here, so a big city isn’t rated riskier just for having more buildings. Castro Valley covers 13 census tracts, combined by population.

Money that reached townFlood claims are matched to Castro Valley’s own flood-insurance community (here, the census tracts inside it); household aid to the registrant’s city; repair grants to Castro Valley. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

FEMA’s expected losses across Castro Valley total about $46.5M a year, counting buildings, people and crops.

Sources: FEMA National Risk Index (December 2025); OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Census tracts: U.S. Census Bureau.