Flood Risk in South San Francisco, CA: 86 FEMA Claims
South San Francisco has significant flood risk — 50% of ZIP codes are in FEMA flood zones.
50% of ZIPs in flood zones · 86 FEMA claims · Updated 2026-05-03
Data: FEMA National Flood Insurance Program (NFIP), FEMA Hazard Mitigation Last verified: 2026-05-03
Within FEMA flood records, South San Francisco has 86 insurance claims on file. Flooding is not covered by most home policies.
What are FEMA flood zones?
FEMA classifies areas into flood zones based on the probability of flooding. High-risk zones (A and V) have a 1% annual chance of flooding and require flood insurance for federally-backed mortgages. Moderate-risk zones (B/X shaded) have a 0.2% annual chance. Even in low-risk zones, about 25% of all flood claims come from areas outside designated high-risk zones. South San Francisco has 50% of ZIP codes in designated flood zones.
How are flood insurance claims calculated?
FEMA tracks every claim filed through the National Flood Insurance Program (NFIP). Claims data includes payouts for building damage and contents loss. High claim counts in an area indicate actual flood events, not just theoretical risk. South San Francisco has 86 recorded claims — this real-world history is often a better risk indicator than flood zone maps alone.
Flood Risk Overview
South San Francisco, California has 50% of its ZIP codes located in FEMA-designated flood zones. A total of 86 flood insurance claims have been filed through the National Flood Insurance Program (NFIP), with $3.7M in total payouts.
The average payout per claim is $43K, reflecting the typical cost of flood damage in the South San Francisco area.
Understanding Flood Zones
FEMA classifies areas into flood zones based on risk:
| Zone | Risk Level | Description |
|---|---|---|
| A, AE, AH, AO | High | 1% annual chance of flooding (100-year floodplain) |
| V, VE | Very High | Coastal areas with wave action |
| B, X (shaded) | Moderate | 0.2% annual chance (500-year floodplain) |
| C, X (unshaded) | Low | Minimal flood risk |
Important: Even "low risk" areas experience flooding. Over 40% of NFIP claims come from outside high-risk zones.
Flood Insurance in South San Francisco
Standard homeowner's insurance does not cover flood damage. Options include:
National Flood Insurance Program (NFIP)
- Available through any insurance agent
- Maximum coverage: $250,000 for building, $100,000 for contents
- Average annual premium: $700–$1,500
- 30-day waiting period before coverage begins
Private Flood Insurance
- Often more coverage at lower premiums
- Faster claims processing
- May offer replacement cost coverage (NFIP pays actual cash value)
Required? If you have a federally backed mortgage and are in a Special Flood Hazard Area (SFHA), flood insurance is mandatory.
How Flooding Affects Drinking Water
Flooding poses direct threats to drinking water quality:
- Water treatment plant overflow — systems can be overwhelmed, leading to untreated or partially treated water
- Sewage contamination — floodwater mixes with sewage systems, introducing bacteria and pathogens
- Agricultural runoff — pesticides, fertilizers, and animal waste enter water supplies
- Well contamination — private wells are especially vulnerable to floodwater infiltration
- Infrastructure damage — pipes can break, creating entry points for contaminants
After a flood event, always follow local boil water advisories and avoid using tap water until the all-clear is given.
FEMA Flood Map for South San Francisco
To check your exact flood zone designation in South San Francisco, use the official FEMA Flood Map Service Center:
- FEMA Flood Map Service Center — enter your address to see your flood zone
- FEMA National Flood Hazard Layer — interactive map viewer
Flood zone distribution of claims in South San Francisco:
| FEMA Zone | Claims | Risk Level |
|---|---|---|
| AH | 34 | High (100-yr floodplain) |
| X | 16 | Moderate-Low |
| C | 12 | Minimal |
| AE | 9 | High (100-yr floodplain) |
| B | 5 | Moderate-Low |
| A | 4 | High (100-yr floodplain) |
NFIP Claims History
| Metric | Value |
|---|---|
| Total claims filed | 86 |
| Total payouts | $3.7M |
| Average per claim | $43K |
| Recent claims (last 5 years) | 41 |
| Recent payouts | $1.4M |
| ZIP codes monitored | 2 |
| Population | 13,511 |
48% of all claims were filed in the last 5 years.
Financial Impact of Flooding in South San Francisco
Flooding in South San Francisco has resulted in $3.7M in total FEMA payouts across 86 claims.
| Impact Metric | Value |
|---|---|
| Average claim amount | $43K |
| Total FEMA payouts | $3.7M |
| Claims per 1,000 residents | 6.4 |
| Payouts per capita | $272 |
Property value impact: Homes in FEMA-designated flood zones typically sell for 4–7% less than comparable homes outside flood zones. Mandatory flood insurance requirements add $700–$1,500/year in carrying costs.
Weather Alerts & Flood Warnings
The National Weather Service (NWS) issues flood watches and warnings for the South San Francisco area. Monitor these resources:
- NWS Weather Alerts — real-time severe weather alerts by location
- Weather.gov California — state-level active alerts
- FEMA Emergency Alerts — IPAWS integrated alerts
Alert types for South San Francisco area:
| Alert Type | Meaning | Action |
|---|---|---|
| Flood Watch | Flooding is possible | Prepare to move to higher ground |
| Flood Warning | Flooding is occurring or imminent | Take action immediately |
| Flash Flood Warning | Flash flooding within hours | Move to high ground now |
| Coastal Flood Advisory | Minor coastal flooding | Monitor conditions |
Set up Wireless Emergency Alerts (WEA) on your phone to receive automatic flood warnings for South San Francisco.
Protecting Your Home from Flooding
Before a flood:
- Know your flood zone — check FEMA's map
- Install sump pump with battery backup
- Elevate electrical systems, furnace, and water heater above potential flood levels
- Apply waterproof sealant to basement walls and floors
- Keep gutters and downspouts clear
During a flood:
- Move to higher ground immediately
- Do not walk or drive through floodwater
- Turn off utilities if instructed
- Monitor local emergency alerts
After a flood:
- Do not drink tap water until the boil water advisory is lifted
- Document damage with photos for insurance claims
- Watch for mold growth in the following weeks
- Have your water tested before resuming normal use
ZIP Codes in South San Francisco
South San Francisco covers 2 ZIP codes. Flood risk varies by ZIP code based on elevation, proximity to water bodies, and drainage infrastructure. Check your specific ZIP code for detailed flood zone mapping.
Data Sources
- Flood claims: FEMA National Flood Insurance Program (NFIP)
- Flood zones: FEMA Flood Map Service Center
- Water quality impact: EPA Emergency Response guidance
Updated daily.
Flood Risk by ZIP Code in South San Francisco
Flood risk varies across South San Francisco's 2 ZIP codes based on elevation, proximity to water bodies, and drainage infrastructure.
| ZIP Code | Grade | Score | Violations | |
|---|---|---|---|---|
| 94080 | B | 73/100 | 0 | View report → |
| 94083 | B | 83/100 | 0 | View report → |