San Anselmo, California Flood Zones
Last updated: March 2026
San Anselmo faces severe flooding from San Anselmo Creek, a major tributary of Corte Madera Creek. The December 2005 floods caused nearly $95 million in damages across the Ross Valley, and the ongoing San Anselmo Flood Risk Reduction project aims to lower flood risk in the downtown area.
Marin County has recorded 3,295 NFIP flood insurance claims since 1978, totaling $51.3M in payouts. Explore the full NFIP claims data by state and county to see how this area compares nationally.
FEMA Region
Region 9
NFIP Policies
7,408
Marin County
Avg. Premium
$1,585/yr
Marin County
FEMA Flood Risk Profile: Marin County
Based on FEMA's National Risk Index, which evaluates flood risk at the county level using historical loss data, exposure, and vulnerability.
Inland Flood Risk
Relatively HighEst. annual loss: $116.0M
Coastal Flood Risk
Very HighEst. annual loss: $19.8M
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
Federal Flood Disaster History: Marin County
Marin County has been included in 10 federal flood-related disaster declarations.
...and 2 earlier declarations since 1964.
These declarations affected communities across Marin County, including San Anselmo.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced February 2026.
NFIP Flood Insurance Claims: Marin County
Properties in Marin County have filed 3,295 NFIP flood insurance claims totaling $51.3M in payouts since 1978. The average claim payout is $16K.
Highest-Claim Years
1982
626 claims - $4.7M
2005
555 claims - $27.9M
1983
498 claims - $4.2M
Claims by Flood Zone
Source: OpenFEMA NFIP Claims API. Data sourced March 2026. See national claims data.
Flood Insurance Coverage: Marin County
An estimated 7% of households in Marin County carry NFIP flood insurance. This county has elevated flood risk with below-average insurance coverage.
Penetration Rate
7%
Claims Ratio
1 in 2
policies have filed a claim
Avg. Claim Payout
$15,558
Derived from FEMA NRI population data and OpenFEMA NFIP policy/claims records.
Repetitive Loss Properties: Marin County
Marin County has 232 properties with multiple flood losses, including 28 severe repetitive loss properties. 1 properties have been mitigated.
Multiple Loss
232
Severe Rep. Loss
28
Mitigated
1
By Flood Zone
Source: OpenFEMA NFIP Multiple Loss Properties. Data sourced March 2026.
Recorded Flood Events: MARIN County
NOAA has recorded 114 flood events in MARIN County since 1996, causing $222.2M in damage.
Costliest Events
Events by Type
Source: NOAA Storm Events Database, 1996-2026. Data sourced March 2026.
Flood Mitigation: Marin County
FEMA has funded mitigation for 54 properties in Marin County, investing $0 in flood risk reduction.
By Action Type
Source: OpenFEMA Hazard Mitigation Assistance. Data sourced March 2026.
What Your Flood Zone Means in San Anselmo
San Anselmo faces flood risk primarily from river and stream overflow during heavy rainfall, snowmelt, or upstream dam releases. When rivers exceed their banks, floodwaters spread across low-lying areas mapped in AE and A zones. The most common FEMA flood zone designations in San Anselmo are Zone AE, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $116.0M. The county is rated "Very High" for coastal flood risk by FEMA's National Risk Index.
Riverine flood risk in San Anselmo is driven by the proximity and elevation of properties relative to nearby waterways. Properties closer to rivers with lower ground elevations typically face higher flood insurance premiums under FEMA's Risk Rating 2.0. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.
River flood maps can change when FEMA conducts new Flood Insurance Studies or when development alters drainage patterns. Letters of Map Amendment (LOMA) can remove individual properties if the natural ground elevation was always above the Base Flood Elevation and the property was inadvertently mapped in the SFHA. Use our free lookup tool to check the current flood zone for any San Anselmo address.
Flood Insurance Discount: San Anselmo
San Anselmo participates in FEMA's Community Rating System (CRS), a voluntary program that rewards communities for flood mitigation efforts beyond minimum NFIP requirements. Residents in the Special Flood Hazard Area may qualify for reduced flood insurance premiums.
CRS Class
Class 8
SFHA Premium Discount
10% off
CRS classes range from 1 (best) to 10 (no discount). San Anselmo's Class 8 rating means NFIP policyholders in the SFHA can receive up to a 10% discount on their flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Source: FEMA Community Rating System, October 2025. Discounts apply to NFIP policies only.
San Anselmo, CA Flood Zone FAQ
What flood zones are in San Anselmo, CA?
The most common FEMA flood zones in San Anselmo are Zone AE, Zone X. Properties in these high-risk zones (SFHA) may require flood insurance with a federally regulated or government-backed mortgage.
Is flood insurance required in San Anselmo?
If your San Anselmo property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance. Properties in Zone X are not federally required to carry flood insurance, though coverage is still recommended since over 40% of all NFIP flood claims come from Zone X properties.
How do I check my flood zone in San Anselmo?
Enter your San Anselmo address in the search tool above for an instant flood zone determination. Results include your FEMA flood zone, SFHA status, base flood elevation (if available), and FIRM panel information, pulled directly from FEMA's National Flood Hazard Layer.
Does San Anselmo offer flood insurance discounts?
Yes. San Anselmo participates in FEMA's Community Rating System (CRS) with a Class 8 rating, qualifying residents in the Special Flood Hazard Area for up to a 10% discount on NFIP flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Has San Anselmo experienced major flooding events?
Marin County, where San Anselmo is located, has been part of 10 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Severe Winter Storms, Flooding, Landslides, and Mudslides in 2023. Federal disaster declarations are issued when flooding overwhelms local resources and triggers FEMA assistance programs.
How many flood insurance claims have been filed in San Anselmo?
Marin County has recorded 3,295 NFIP flood insurance claims totaling $51.3M in payouts since 1978. The year with the most claims was 1982, with 626 claims and $4.7M in payouts. These figures cover all NFIP claims in the county, including San Anselmo.
How many flood insurance policies are active in San Anselmo?
Marin County currently has 7,408 active NFIP flood insurance policies with an average annual premium of $1,585. The most policies are in Zone AE (4,580 policies). These figures cover all active NFIP policies in the county.
How many San Anselmo properties have flooded repeatedly?
Marin County has 232 properties with multiple flood losses on record, including 28 severe repetitive loss properties. These are properties that have experienced four or more NFIP claims of $5,000+ or two claims exceeding the building value.
Can my San Anselmo property be removed from a high-risk flood zone?
Yes, if your property's natural ground elevation is above the Base Flood Elevation and FEMA inadvertently mapped it in a high-risk zone, you can apply for a Letter of Map Amendment (LOMA). A successful LOMA removes the property from the Special Flood Hazard Area, generally eliminating the federal mandatory flood insurance requirement. You will need an elevation certificate from a licensed surveyor. If a property was raised above the BFE with fill material, the process is a LOMR-F rather than a LOMA.
What is Base Flood Elevation in San Anselmo?
Base Flood Elevation (BFE) is the predicted height of floodwaters during a 1% annual chance (100-year) flood, shown on FEMA maps as an elevation number in feet above sea level. In San Anselmo's Zone AE areas, BFE lines appear on the FIRM as wavy contours labeled with elevation values. Properties with a lowest floor at or above the BFE typically qualify for significantly lower NFIP flood insurance premiums.
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Disclaimer: Flood risk data on this page is sourced from FEMA datasets including the National Risk Index, NFIP claims and policy records, disaster declarations, and the Community Rating System. These datasets were last extracted on March 2026 and may not reflect the most recent changes. This page is for informational purposes only and is not a certified flood zone determination. Always verify current flood zone status through FEMA or a licensed determination provider before making property, insurance, or lending decisions.