About FloodRoute
A street-by-street king tide forecast, built by one neighbor in Marin County.
FloodRoute was inspired by my Nextdoor neighbors in Marin County, California. After the roads around the Tiburon Peninsula flooded in early January 2026, I shared the idea for an app that shows which streets flood at high tide, and when. Within 24 hours, nearly 200 neighbors had asked me to build it.
So I did. FloodRoute was my first iOS app, and The Ark put it on its front page.
FloodRoute 2.0 turns it into something neighbors build together: a free live map for every covered town, forecasts that follow the real water level, and flood photos posted by the people who live there. It now covers towns from San Francisco Bay to Boston and Miami, and anyone can ask for theirs.
It's still built by one person, and Pro keeps the free map free.
Marc Hoag
“Strawberry resident launches flood app based on the tides”
Where the data comes from
- NOAA CO-OPS: tide predictions and live water levels
- USGS 3D Elevation Program: road elevations
- OpenStreetMap and Overture Maps: road geometry
- FEMA National Flood Hazard Layer: flood zones
- Open-Meteo: rainfall and barometric pressure
- Neighbors' reports and documented king tide flooding: calibration
More on how the forecast works in Support & FAQ.
Get in touch
Questions, corrections or a town to add: contact@axiomic.ai. Journalists, see the press kit. FloodRoute is made by Axiomic, LLC.
I also build Towne, an ad-free, invite-only neighborhood network.
