# FloodRoute: know which roads flood before you leave > Because cars can’t swim. FloodRoute shows which roads in your town flood at high tide — when, how badly, and for how long — days before the water arrives. Free on iPhone · live maps for 20 coastal towns · no account needed. [Get FloodRoute on the App Store](https://apps.apple.com/app/id6757653475) · [Find your town](https://floodroute.com/towns.md) **Forecasts are estimates, not guarantees.** Never drive or walk through flood water: according to the National Weather Service, a foot of moving water can carry away most cars. Turn around, don’t drown. Always follow local authorities and official warnings. ## What's new in FloodRoute 2.0 - **Live water levels.** Catches the surges tide tables miss. - **Exact times & streets.** When, where and how deep. - **Alerts for your street.** Home, work and your commute. - **Neighbor reports.** See it, snap it, share it. - **Share with anyone.** Live maps open in any browser. - **30 years of history.** Every king tide since 1996. In two years of testing, next-day forecasts landed within 3 inches of the real water 80% of the time. Tide tables alone: 28%. ## This week in covered towns - [Corte Madera, CA](https://floodroute.com/ca/corte-madera.md): Clear today · Next flood window Fri 9:20–11:20 AM - [Larkspur, CA](https://floodroute.com/ca/larkspur.md): Clear today · Next flood window Fri 9:20–11:20 AM - [San Rafael, CA](https://floodroute.com/ca/san-rafael.md): Clear today · Next flood window Fri 9:20–11:20 AM - [Marin County, CA](https://floodroute.com/ca/marin-county.md): Clear today · Next flood window Fri 9:20–11:20 AM - [Tam Junction, CA](https://floodroute.com/ca/tam-junction.md): Clear today · Next flood window Fri 9:20–11:20 AM - [Tiburon, CA](https://floodroute.com/ca/tiburon.md): Clear today · Next flood window Fri 9:20–11:20 AM All towns: https://floodroute.com/towns.md ## The app ### See it before it happens Drag through the week's tides and watch the water rise and fall on your streets, hour by hour. ### Ask “what if?” Drag the water level up and see exactly which roads go under at a storm or king tide. ### Your street, your alerts Save home and work. We warn you hours before the roads around them flood — not just “high tide somewhere.” ### Warn your neighbors One tap shares a link to a live flood map. Neighbors don't need the app to see it. ## How it works: a forecast for your street, not just your coast 1. **Tide predictions.** NOAA publishes the time and height of every high tide months ahead — and we add the live water level when the bay runs high. 2. **Every road's low point.** We measured the elevation along every street in each town, so we know where the water gets in first. 3. **Which streets flood, when.** Put them together and you get a street-by-street forecast: “Tiburon roads flood Sat 9:40–11:15 AM.” ## As seen on Front page of The Ark (Tiburon). Made in Marin County, California — and covered by the Marin IJ. [Press kit](https://floodroute.com/press.md) ## Covered towns ### California - [Sausalito](https://floodroute.com/ca/sausalito.md) - [Mill Valley](https://floodroute.com/ca/mill-valley.md) - [Tam Junction](https://floodroute.com/ca/tam-junction.md) - [Tiburon](https://floodroute.com/ca/tiburon.md) - [Belvedere](https://floodroute.com/ca/belvedere.md) - [Corte Madera](https://floodroute.com/ca/corte-madera.md) - [Larkspur](https://floodroute.com/ca/larkspur.md) - [San Rafael](https://floodroute.com/ca/san-rafael.md) - [Santa Venetia](https://floodroute.com/ca/santa-venetia.md) - [Novato](https://floodroute.com/ca/novato.md) - [San Francisco](https://floodroute.com/ca/san-francisco.md) ### Massachusetts - [Boston](https://floodroute.com/ma/boston.md) ### New York - [New York City](https://floodroute.com/ny/new-york-city.md) ### Florida - [Miami](https://floodroute.com/fl/miami.md) - [Tampa](https://floodroute.com/fl/tampa.md) - [Fort Lauderdale](https://floodroute.com/fl/fort-lauderdale.md) (beta) - [North Miami](https://floodroute.com/fl/north-miami.md) (beta) ### South Carolina - [Charleston](https://floodroute.com/sc/charleston.md) (beta) ### Virginia - [Norfolk](https://floodroute.com/va/norfolk.md) (beta) - [Virginia Beach](https://floodroute.com/va/virginia-beach.md) (beta) ## Not covered yet? Map my town FloodRoute covers coastal towns where the tide floods the roads. Request yours and share the link with neighbors — the most-requested towns get mapped first, and everyone who asked hears the day it launches. Request your town: https://floodroute.com/towns#request · Most-requested towns: https://floodroute.com/towns#leaderboard ## Frequently asked questions ### What is FloodRoute? FloodRoute forecasts which streets in US coastal towns flood at high tide and during king tides: when, how badly and for how long. It's a free iPhone app and a free website with live street-level flood maps for 39 coastal towns and neighborhoods in 6 states. FloodRoute is made in Marin County, California, by Axiomic, LLC. ### How does FloodRoute know which roads flood? It combines NOAA tide predictions for the nearest tide station with the measured elevation along every street in each town. When the water is forecast to rise above a road's lowest point, the road is marked as possible (amber), likely (orange) or severe (red) flooding, depending on how far the water rises above it. Where a nearby NOAA gauge measures live water levels, the forecast is corrected when the water is running above or below the tide tables. After each high tide, streets stay marked a little longer, because water drains off roads more slowly than the tide falls. Heavy recent rain raises the next 24 hours. ### How accurate are the forecasts? They're estimates, not guarantees. Wind, storm surge, blocked drains, construction and local quirks can change what actually floods, and new towns launch in Beta until community reports confirm them. In backtests at six NOAA stations (October 2024 to October 2026), the live gauge correction cut the typical error in high-tide water levels over the next 24 hours from about 0.57 ft to about 0.23 ft. Treat FloodRoute as a heads-up: **never drive or walk through flood water**, and follow local authorities and official warnings. ### Does FloodRoute forecast river floods or flash floods? No. FloodRoute covers coastal tidal flooding only: streets that flood when high tides and king tides push bay or ocean water onto the road. It does not forecast river, creek or flash flooding, drainage failures, or storm surge beyond what nearby gauges currently measure. For those, follow the National Weather Service and local authorities. ### Is FloodRoute free? What does Pro add? The website is free, and so is the core of the iPhone app: the live flood map and tide scrubber, the 7-day flood outlook, community reports, sharing, calendar feeds, one saved place, and a heads-up before flood windows in your home town (plus a king tide heads-up the evening before). FloodRoute Pro adds street-level alerts for up to three saved places, commute alerts, the 30-day planner, the what-if simulator and alerts for more towns. Pro is a monthly or yearly subscription through the App Store. Everyone starts with Pro free, with no payment details, until two days after the next notable high tide in their town (at least 7 and at most 30 days). After that the app switches to the free features; you're never locked out. ### Which towns does FloodRoute cover? 39 coastal towns and neighborhoods in 6 states. California: Marin County and San Francisco; Massachusetts: Boston; New York: New York City; Florida: Miami, Tampa, Fort Lauderdale (beta) and North Miami (beta); South Carolina: Charleston (beta); Virginia: Norfolk (beta) and Virginia Beach (beta). Towns marked Beta are new and still being confirmed by community reports. See the [full list of covered towns](https://floodroute.com/towns). ### My town isn't covered. Can you add it? Yes. [Request your town](https://floodroute.com/towns#request) and share your link with neighbors. The most-requested towns get mapped first, and if you leave your email, we'll tell you the day your town launches. ### Does FloodRoute track my location? Do I need an account? There are no accounts. Location access is optional and only used while the app is open. Your location is processed on your device and never leaves it unless you submit a flood report (its pin is public) or choose to attach it to a town request. Saved places and commutes stay on your device and sync through your own iCloud. We don't sell your data or use advertising identifiers. See the [Privacy Policy](https://floodroute.com/privacy). ### Can I share a flood forecast with my neighbors? Yes. Every town and every flood day has its own link, and its preview card shows the forecast in iMessage, Facebook or Nextdoor. Neighbors can open the live map in any browser, with no app needed. You can also subscribe to a town's flood-day calendar or print a flyer for a bulletin board. Because cars can’t swim. Free on iPhone. Pro adds alerts for your street and your commute: https://apps.apple.com/app/id6757653475 --- Web version: https://floodroute.com/ · Site index for AI agents: https://floodroute.com/llms.txt · Every page is available as Markdown: add `.md` to its URL. FloodRoute provides estimates only. Never drive or walk through flood water. © Axiomic, LLC · contact@axiomic.ai