2026-04-05

Tide Line

Your coast is flooding more than it used to. We count the days, project the future, and tell you exactly when your street goes underwater — with government data, not vibes.

Consumer-facing high-tide flooding intelligence — city-by-city flood day scorecards, historical trend analysis, decade-ahead projections, property risk context, and "sunny day flooding" dispatches, all auto-generated from NOAA's free APIs and delivered as beautiful, hyperlocal data journalism.

Niche Explored

Consumer-facing sunny-day / high-tide flooding intelligence — translating NOAA tidal data, sea level rise projections, and FEMA flood maps into location-specific property risk reports, flooding trend scorecards, and forward-looking “when will my street flood regularly?” timelines.

Existing Competition

sunnydayflooding.com — Academic research project (UNC/Virginia Institute of Marine Science). Sensor-based data for a handful of NC communities. Not consumer-friendly, no property value angle, limited geographic scope. Research-oriented, not content-driven.
doesitflood.com — Aggregates FEMA maps + USGS water data + community reports. Mostly a lookup tool, not editorial content. No data journalism or trend analysis.
homedatareports.com — Property risk report aggregator. Purely transactional — pay per report. No editorial, no stories, no ongoing content.
climatesafe.io — Similar to homedatareports. Commercial property risk reports. Not a content channel.
First Street Foundation — Premium API and reports. Excellent data but behind paywalls. No consumer-facing editorial content.
The Invading Sea — Florida-focused editorial site. Good journalism but manually produced, not automated, not data-driven in a systematic way.
NOAA’s own dashboards — Incredible data (tidesandcurrents.noaa.gov) but presented in raw government format. No narratives, no property value context, no consumer-friendly interpretation.

GAP: Nobody is combining NOAA’s free high-tide flooding APIs with FEMA flood maps, sea level rise projections, and property value research into automated, beautiful, city-by-city data journalism. The data is FREE and RICH — it just needs translation.

Data Sources Found

Primary: NOAA CO-OPS APIs (FREE, no API key needed)

High Tide Flooding - Annual Flood Count API: https://api.tidesandcurrents.noaa.gov/dpapi/prod/webapi/htf/htf_annual.json — Historical flood day counts per station going back to 1920s. Confirmed working — returns clean JSON with minor/moderate/major flood day counts.
High Tide Flooding - Monthly Flood Count: htf_monthly.json — Monthly breakdown of flood days per station.
High Tide Flooding - Daily Likelihoods: htb.json — Forward-looking flood probability for each station, each day. Can query for “which stations have flooding likely today?”
High Tide Flooding - Decadal Projections: htf_projection_decadal.json — Projected flood days per decade under different sea level rise scenarios (low/intermediate/high). CONFIRMED: The Battery, NY projects 10 minor flood days/year in 2020s → 125 days/year by 2050s under high scenario.
High Tide Flooding - Record Days: htf_record.json — Record flood years vs typical days in 2000.
Sea Level Rise Projections: slr_projections.json — Station-specific sea level rise projections under multiple scenarios.
Sea Level Trends: sealvltrends.json — Historical sea level trends per station.
NOAA Data Retrieval API: api.tidesandcurrents.noaa.gov/api/prod/ — Real-time water levels, predictions, air/water temp.
CO-OPS Metadata API: tidesandcurrents.noaa.gov/mdapi/latest/ — Station metadata (200+ stations with flooding data).

Secondary: FEMA

National Flood Hazard Layer (NFHL): Free ArcGIS REST service at hazards.fema.gov/arcgis/rest/services/public/NFHL/MapServer — flood zone boundaries, base flood elevations. Can be queried programmatically.

Tertiary: Research & Context

Richmond Fed Economic Brief (Nov 2025): “Sea Level Rise and Effects on House Prices” — peer-reviewed data on property value impacts.
Nature Communications (2024): “Policy and market forces delay real estate price declines on the US coast” — research showing coastal property prices haven’t yet reflected true flood risk.
Connecticut 2026 Flood Disclosure Law — New requirement for flood history disclosure in real estate transactions. Sign of growing regulatory trend.
WRAL (July 2025): “Sensors reveal a ‘sunny day’ flooding crisis on North Carolina coast” — major media coverage indicating growing public awareness.

Verified API Call Examples

# Annual flood days for The Battery, NY (2020-2025):
# 2020: 11 minor days → 2024: 26 minor days (136% increase in 4 years!)
curl "https://api.tidesandcurrents.noaa.gov/dpapi/prod/webapi/htf/htf_annual.json?station=8518750&year=2020&range=5"

# Decadal projections for The Battery, NY:
# 2020s: 10 minor flood days/year → 2050s: 85-125 days/year → 2090s: 345-365 days/year
curl "https://api.tidesandcurrents.noaa.gov/dpapi/prod/webapi/htf/htf_projection_decadal.json?station=8518750"

# Which stations expect flooding today?
curl "https://api.tidesandcurrents.noaa.gov/dpapi/prod/webapi/htb.json?date=20260405&station_flood=true"

SEO Analysis

Keywords with opportunity:
- “sunny day flooding” — growing search term, limited quality content
- “high tide flooding [city name]” — hyperlocal, low competition for most cities
- “will my house flood” / “flood risk by address” — high intent, high volume
- “sea level rise [city]” — growing volume, mostly generic results
- “coastal property flood risk” — high commercial intent (real estate buyers)
- “king tide flooding” — seasonal spikes in search volume
- “flood disclosure law” — new regulatory searches emerging
SEO strength: Location-specific pages (“Annapolis high tide flooding trends”) would rank easily — very few automated competitors creating city-by-city content at scale
Long-tail gold: “[city name] flood days per year” — almost zero competition, real data to answer

Communities

Reddit: r/RealEstate, r/FirstTimeHomeBuyer, r/climate, r/florida, r/Charleston, r/Annapolis — frequent questions about flood risk when buying
Facebook groups: Coastal homeowner groups, specific city/neighborhood groups
NextDoor: Hyperlocal flood complaints are extremely common in coastal communities
Real estate forums: BiggerPockets (investors constantly asking about flood zone properties)

Image/Graphic Feasibility

Excellent for auto-generation:
- Line charts: Flood days per year over time (from API data)
- Heatmaps: Monthly flooding patterns (seasonal visualization)
- Bar charts: City-by-city flood day rankings
- Projection curves: Future flood days under different scenarios (spectacular visual from decadal projection data)
- Simple maps: Station locations with flood status indicators
AI image generation:
- Conceptual illustrations of sunny-day flooding scenes
- Before/after style visualizations
- City-specific header images
Challenge: Interactive maps would require client-side JavaScript (feasible in static site with Leaflet/MapLibre)