NOAA Sea Level Projections for Your ZIP Code

Data source: ZipCheckup analysis of NOAA climate projections (RCP 4.5), FEMA NFIP flood claims, Census ACS

NOAA publishes sea level rise projections for every stretch of the American coastline. The data is specific, peer-reviewed, and publicly available. It shows exactly how many inches of rise each coastal region can expect under various emissions scenarios — and which communities sit in the path.

When you combine those projections with FEMA's historical flood damage data, the picture that emerges is not abstract. It's measured in billions of dollars already spent and millions of residents already affected.

25 States, 12-18 Inches

Under the intermediate projection scenario (RCP 4.5 — roughly corresponding to current global emissions trends), NOAA projects significant sea level rise for 25 U.S. coastal states by 2100:

Louisiana faces the highest projected rise — 18 inches — because it contends with both rising seas and land subsidence. The Mississippi Delta is sinking as sea levels climb, creating a double effect that no seawall can fully address.

Florida's situation is uniquely challenging for a different reason: its porous limestone geology means that seawalls are largely ineffective. Seawater doesn't just come over the barriers — it comes up through the ground.

$87.9 Billion Already Paid

FEMA's National Flood Insurance Program has already paid out $87.9 billion in claims across 2.6 million claims nationwide. These aren't projections — they're checks that have already been written.

The three states with the highest payouts:

1. Louisiana — $20.7 billion (477,920 claims)
2. Florida — $19.2 billion (444,044 claims)
3. Texas — $17.3 billion (388,090 claims)

Together, these three states account for 65% of all federal flood insurance payouts in American history. And the projections indicate the worst is ahead, not behind.

What Sea Level Rise Does to Water Quality

The connection between rising seas and drinking water quality is direct and measurable:

Saltwater Intrusion

As sea levels rise, saltwater pushes into freshwater aquifers that supply drinking water to coastal communities. This saltwater intrusion is already measurable in South Florida, coastal New Jersey, and parts of the Carolinas. Once an aquifer is contaminated with saltwater, remediation is extremely difficult and expensive.

Source-water type is the variable that matters: across the 5,572 public utilities tracked in the CCR Rich Dataset, every utility discloses whether its supply is groundwater, surface water, blended, or purchased — and coastal groundwater systems are the ones most exposed to saltwater-intrusion failure as sea level climbs.

Infrastructure Flooding

Higher tides and more frequent storm surges flood water treatment plants, pump stations, and sewer systems. When treatment facilities flood, the result is often raw sewage releases into waterways and drinking water sources. FEMA data shows that flood-prone ZIP codes have 27% more active EPA water quality violations than inland areas at similar income levels.

Groundwater Stress

Our data tracks groundwater stress levels by state. The overlap between high sea level rise projections and high groundwater stress is significant:

• Texas — 16 inches projected rise + groundwater stress score of 65/100
• Florida — 14 inches + groundwater stress of 55/100
• New Jersey — 14 inches + groundwater stress of 20/100 (but 92% of ZIPs have water violations)

Texas faces the worst compound scenario: high sea level rise, high drought stress (score 57), and extensive reliance on stressed groundwater aquifers.

The Infrastructure Vulnerability Layer

Sea level rise hits hardest where infrastructure is already aging. Our data combines NOAA projections with infrastructure vulnerability scores — and the overlap is significant:

• Rhode Island — 12 inches SLR + infrastructure vulnerability of 85/100 (the highest in the nation). With 49% of housing predating 1970, the state's water systems are among the oldest and most vulnerable to flooding.
• New York — 13 inches SLR + infrastructure vulnerability of 82/100. Median water system age: 67 years.
• New Jersey — 14 inches SLR + infrastructure vulnerability of 74/100. 92% of ZIPs have water violations on record.
• Pennsylvania — 12 inches SLR + infrastructure vulnerability of 71/100 along the Delaware River corridor.

These states don't just face rising water from the coast — they face it with pipes and treatment systems that are already past their design lifespan.

What This Means for Property Values

The financial implications are becoming impossible to ignore. Research from the National Bureau of Economic Research shows that properties in flood-exposed ZIP codes are beginning to see valuation discounts — a trend that will accelerate as insurance costs rise and sea level projections become more visible in real estate disclosures.

Our data shows the financial footprint for the most-exposed areas:

• Louisiana ZIP codes have received an average of $43,300 per flood claim from FEMA
• New York ZIP codes average $32,800 per claim
• Florida ZIP codes average $43,200 per claim

These per-claim averages have been rising year over year, reflecting both increased damage severity and rising property values in flood zones.

Check Your ZIP Code's Climate Exposure

Every ZipCheckup report now includes climate resilience data:

• Sea level rise projection for your state (inches, by 2100)
• FEMA flood claims history — how many claims filed from your ZIP, total payouts
• Flood zone classification from FEMA maps
• Groundwater stress and drought risk scores
• Infrastructure vulnerability — system age, violation history, and capacity

The NOAA data has been public for years. The FEMA claims data has been public for years. What hasn't been easy is connecting them to your specific ZIP code and seeing the full picture. Now you can.

Check your ZIP code now →

Methodology: Sea level rise projections from NOAA Technical Report NOS CO-OPS 083, using the Intermediate (RCP 4.5) scenario. Flood data from FEMA National Flood Insurance Program claims database. Infrastructure vulnerability scores combine Census housing vintage data (year structure built), EPA SDWIS violation rates, and estimated water system median age. Groundwater stress from USGS water use data and aquifer depletion rates. Coverage: 25 coastal states with measurable SLR projections, 26,172 ZIP codes with FEMA flood claims history.