San Marcos, Texas Flood Zones
Last updated: March 2026
San Marcos faces flooding from the San Marcos River and Blanco River in Hays County. Flash flooding from Hill Country thunderstorms causes rapid river rises in this Central Texas community.
Hays County has recorded 1,489 NFIP flood insurance claims since 1978, totaling $71.4M in payouts. Explore the full NFIP claims data by state and county to see how this area compares nationally.
FEMA Region
Region 6
NFIP Policies
2,248
Hays County
Avg. Premium
$1,043/yr
Hays County
FEMA Flood Risk Profile: Hays 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 ModerateEst. annual loss: $68.1M
Hurricane Risk
Relatively LowEst. annual loss: $388K
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
Federal Flood Disaster History: Hays County
Hays County has been included in 9 federal flood-related disaster declarations.
...and 1 earlier declaration since 1972.
These declarations affected communities across Hays County, including San Marcos.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced February 2026.
NFIP Flood Insurance Claims: Hays County
Properties in Hays County have filed 1,489 NFIP flood insurance claims totaling $71.4M in payouts since 1978. The average claim payout is $48K.
Highest-Claim Years
2015
731 claims - $58.8M
1998
254 claims - $3.6M
1981
114 claims - $999K
Claims by Flood Zone
Source: OpenFEMA NFIP Claims API. Data sourced March 2026. See national claims data.
What Your Flood Zone Means in San Marcos
San Marcos 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 Marcos are Zone AE, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $68.1M.
Riverine flood risk in San Marcos 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 Marcos address.
Flood Insurance Discount: San Marcos
San Marcos 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 7
SFHA Premium Discount
15% off
CRS classes range from 1 (best) to 10 (no discount). San Marcos's Class 7 rating means NFIP policyholders in the SFHA can receive up to a 15% 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 Marcos, TX Flood Zone FAQ
What flood zones are in San Marcos, TX?
The most common FEMA flood zones in San Marcos 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 Marcos?
If your San Marcos 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 Marcos?
Enter your San Marcos 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 Marcos offer flood insurance discounts?
Yes. San Marcos participates in FEMA's Community Rating System (CRS) with a Class 7 rating, qualifying residents in the Special Flood Hazard Area for up to a 15% discount on NFIP flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Has San Marcos experienced major flooding events?
Hays County, where San Marcos is located, has been part of 9 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in 2024. 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 Marcos?
Hays County has recorded 1,489 NFIP flood insurance claims totaling $71.4M in payouts since 1978. The year with the most claims was 2015, with 731 claims and $58.8M in payouts. These figures cover all NFIP claims in the county, including San Marcos.
How many flood insurance policies are active in San Marcos?
Hays County currently has 2,248 active NFIP flood insurance policies with an average annual premium of $1,043. The most policies are in Zone X (934 policies). These figures cover all active NFIP policies in the county.
Can my San Marcos 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 Marcos?
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 Marcos'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.
Other Texas Cities
Understanding Flood Zones
Look Up Any San Marcos, TX Address
Enter a San Marcos, TX address to instantly check its FEMA flood zone designation, SFHA status, and insurance requirements.
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.