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Live flood monitor

Real-time river flooding
across America.

Live USGS streamgauge readings, FEMA flood zones, NWS flood watches and warnings, and historical context — one map, refreshed throughout the day. Built for flood researchers, emergency managers, and outdoor recreationists.

Last updated September 29, 2026 · 141 sensors live
Rivers above flood
56
Watersheds elevated
89
Active flood sensors
141
USGS gauges tracked
10K+
Layers
Flow vs. normal
< 50%
~ 100%
200%
500%+
Tiles © Mapbox · Data USGS, NOAA NWS, FEMA, NRCS · Click any feature for details · Multiple layers under your click aggregate into one popup.
Right now

Rivers currently flooding or rising

Live USGS streamgauge readings aggregated by river. Percent-of-normal compares current flow to the seasonal average.

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River Observed (cfs) Seasonal avg (cfs) vs. Normal
Black Warrior River 2,060 2,205 93% of normal
Paskamanset River 268 5 ↑ 5071% of normal
Suwannee River 5,420 7,030 77% of normal
Edwards River 313 51 ↑ 619% of normal
Wapsipinicon River 8,190 604 ↑ 1356% of normal
Still River 347 28 ↑ 1262% of normal
Salt River 366 20 ↑ 1821% of normal
Tygart Valley River 13,200 804 ↑ 1643% of normal
Lackawaxen River 1,290 204 ↑ 632% of normal
Mill River 374 23 ↑ 1612% of normal
Delaware River 1,790 189 ↑ 950% of normal
Taunton River 1,830 110 ↑ 1664% of normal
Neponset River 1,202 86 ↑ 1404% of normal
Middle Raccoon River 1,009 106 ↑ 953% of normal
Nodaway River 3,450 144 ↑ 2396% of normal
North Raccoon River 337 28 ↑ 1212% of normal
Pecos River 1,391 117 ↑ 1192% of normal
Queen River 162 9 ↑ 1841% of normal
Coginchaug River 390 6 ↑ 6522% of normal
Jones River 248 12 ↑ 2138% of normal
Whippany River 405 43 ↑ 940% of normal
Blackstone River 1,210 201 ↑ 603% of normal
Republican River 740 50 ↑ 1480% of normal
Cedar River 13,611 2,189 ↑ 622% of normal
Animas River 1,120 179 ↑ 626% of normal
Tombigbee River 3,592 7,669 47% of normal
Souris River 328 43 ↑ 769% of normal
Quinsigamond River 172 6 ↑ 2867% of normal
Neversink River 477 77 ↑ 620% of normal
Ware River 358 35 ↑ 1026% of normal
Titicus River 155 11 ↑ 1409% of normal
Threemile River 381 25 ↑ 1524% of normal
Little Colorado River 307 5 ↑ 6079% of normal
Teton River 287 18 ↑ 1640% of normal
North Canadian River 594 33 ↑ 1828% of normal
Croton River 1,040 144 ↑ 722% of normal
Iowa River 4,980 307 ↑ 1622% of normal
Buckhannon River 511 32 ↑ 1612% of normal
Samish River 21 29 71% of normal
Straight River 855 82 ↑ 1047% of normal
Wood River 642 52 ↑ 1229% of normal
Chariton River 414 16 ↑ 2540% of normal
Westfield River 486 64 ↑ 761% of normal
Watonwan River 279 44 ↑ 637% of normal
Salmon River 219 23 ↑ 952% of normal
Stillwater River 315 3 ↑ 9403% of normal
Branch River 218 27 ↑ 796% of normal
Saugatuck River 186 21 ↑ 882% of normal
Raccoon River 1,310 193 ↑ 679% of normal
North Nashua River 547 42 ↑ 1315% of normal
Usquepaug River 182 21 ↑ 863% of normal
Hunt River 188 8 ↑ 2293% of normal
Middle Fork River 278 17 ↑ 1645% of normal
Indian Head River 459 13 ↑ 3477% of normal
Green River 364 496 73% of normal
Blue Earth River 1,930 147 ↑ 1313% of normal

56 rivers are running elevated right now. Create a free account to see the full list, follow your rivers, and get alerts.

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By basin

Watersheds running elevated

Aggregated by HUC8 watershed code. Useful for catchment-level flood-risk assessment.

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HUC8 code Watershed Observed (cfs) vs. Normal
h01100006 Saugatuck 186 ↑ 882%
h01100005 Housatonic 347 ↑ 1262%
h01100004 Quinnipiac 269 ↑ 4339%
h03110205 Lower Suwannee 5,420 77%
h12040104 Buffalo-San Jacinto 204 ↑ 2914%
h10030203 Marias 287 ↑ 1640%
h02030101 Lower Hudson 1,547 ↑ 770%
h02030103 Hackensack-Passaic 405 ↑ 940%
h02030105 Raritan 1,877 ↑ 4888%
h02050201 Upper West Branch Susquehanna 583 ↑ 624%
h03080103 Lower St. Johns 72,235 60%
h07080105 South Skunk 663 ↑ 6630%
h07080104 Flint-Henderson 313 ↑ 619%
h07080103 Lower Wapsipinicon 8,190 ↑ 1356%
h07100009 Lower Des Moines 20,977 ↑ 2464%
h07100008 Lake Red Rock 751 ↑ 4700%
h07100004 Middle Des Moines 4,730 ↑ 1042%
h07100007 South Raccoon 1,009 ↑ 953%
h07100006 North Raccoon 1,647 ↑ 746%
h05050007 Elk 386 ↑ 658%
h01080201 Middle Connecticut 105 ↑ 618%
h14080104 Animas 1,120 ↑ 626%
h14080101 Upper San Juan 325 ↑ 855%
h17110002 Strait Of Georgia 21 71%
h15020016 Lower Little Colorado 307 ↑ 6079%
h07040002 Cannon 855 ↑ 1047%
h18070102 Santa Clara 398 ↑ 4270%
h05010008 Kiskiminetas 960 ↑ 888%
h05010007 Conemaugh 154 ↑ 969%
h05010006 Middle Allegheny-Redbank 1,000 ↑ 893%
h10250017 Lower Republican 740 ↑ 1480%
h02050301 Lower Susquehanna-Penns 225 ↑ 772%
h02040301 Mullica-Toms 381 ↑ 632%
h02040302 Great Egg Harbor 382 ↑ 1065%
h10280103 Lower Grand 846 ↑ 2690%
h02040201 Crosswicks-Neshaminy 1,595 ↑ 2029%
h03160113 Lower Black Warrior 2,060 93%
h02040202 Lower Delaware 216 ↑ 2175%
h05020002 West Fork 1,040 ↑ 1463%
h05060001 Upper Scioto 306 ↑ 718%
h05020001 Tygart Valley 30,289 ↑ 1893%
h07080205 Middle Cedar 13,210 ↑ 692%
h07080207 Upper Iowa 362 ↑ 995%
h18070203 Santa Ana 419 ↑ 4935%
h07080201 Upper Cedar 962 ↑ 925%
h07120004 Des Plaines 1,030 ↑ 476%
h07080208 Middle Iowa 6,155 ↑ 1544%
h07080209 Lower Iowa 446 ↑ 1802%
h01090002 Cape Cod 975 ↑ 3241%
h03160106 Middle Tombigbee-Lubbub 902 66%
h13060001 Pecos Headwaters 301 ↑ 5281%
h10280201 Upper Chariton 414 ↑ 2540%
h13020203 Rio Grande-Albuquerque 173 ↑ 1123%
h10240010 Nodaway 3,450 ↑ 2396%
h01080206 Westfield 486 ↑ 761%
h01080204 Chicopee 358 ↑ 1026%
h01080205 Lower Connecticut 609 ↑ 2101%
h11100301 Middle North Canadian 594 ↑ 1828%
h07110005 North Fork Salt 366 ↑ 1821%
h07020011 Le Sueur 2,520 ↑ 3673%
h17110013 Duwamish 364 73%
h03160201 Middle Tombigbee-Chickasaw 2,690 43%
h10270103 Delaware 1,790 ↑ 950%
h07080107 Skunk 649 ↑ 5571%
h03180002 Middle Pearl-Strong 435 ↑ 7909%
h02020005 Schoharie 2,616 ↑ 4794%
h12030108 Richland 466 ↑ 5210%
h07020010 Watonwan 279 ↑ 637%
h04100004 St. Marys 460 ↑ 1901%
h05040006 Licking 159 ↑ 1060%
h07020009 Blue Earth 1,930 ↑ 1313%
h01070004 Nashua 862 ↑ 1918%
h03050201 Cooper 7,180 ↑ 732%
h05060003 Paint 1,249 ↑ 1099%
h02040104 Middle Delaware-Mongaup-Brodhead 477 ↑ 620%
h02040105 Middle Delaware-Musconetcong 645 ↑ 2386%
h02040103 Lackawaxen 1,290 ↑ 632%
h05130101 Upper Cumberland 171 ↑ 1103%
h13060011 Upper Pecos-Black 1,090 ↑ 982%
h15010015 Las Vegas Wash 498 ↑ 1186%
h09010003 Lower Souris 328 ↑ 769%
h01090001 Charles 2,066 ↑ 1833%
h01090003 Blackstone 778 ↑ 800%
h03080101 Upper St. Johns 4,410 107%
h01090005 Pawcatuck-Wood 1,203 ↑ 1111%
h01090004 Narragansett 3,967 ↑ 1053%
h13020211 Elephant Butte Reservoir 981 ↑ 1143%
h05130202 Lower Cumberland-Sycamore 4,860 ↑ 607%
h17110012 Lake Washington 26 100%

89 watersheds are running elevated. Create a free account to see every basin.

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Go deeper

Monitoring & response toolkit

Everything on this page links into Snoflo’s gauge-level data — drill from a national view down to the readings on a single river.

Gauge-level flow reports

Every USGS streamgauge by state — live discharge, gage height, NWS flood stages, and the complete observation history.

Browse gauges →

15-day flow forecasts

PULSE probabilistic outlooks on every gauge — median, likely range, and projected stage, refreshed daily.

How PULSE works →

Engineering data & reports

Flow-duration statistics, observed peak context, CSV exports, and printable conditions reports for any gauge and date range.

Snoflo for Engineering →

Interactive national map

Layer gauges, warnings, watersheds, rain, and recreation across the country on one map.

Open the map →
Background

What causes river flooding

Flooding is rarely a single-cause event — multiple factors usually compound. The most common drivers across the U.S.

🌧

Heavy rainfall

Persistent rain saturates soils and overwhelms drainage networks. Tropical systems and atmospheric rivers are the worst culprits.

⛄

Rapid snowmelt

Spring melt pulses can deliver months of accumulated water in days — especially when warm rain falls on existing snowpack.

🧊

Ice jams

Breakup ice can block channels, forcing water to back up and inundate upstream banks. Common on northern rivers in early spring.

🌊

Storm surge

Coastal hurricanes push seawater inland. Surge combined with rainfall is the deadliest flood scenario in U.S. history.

🛡

Reservoir releases

Controlled dam releases can dramatically increase downstream flow. USACE and USBR publish release schedules, but conditions change fast.

🌌

Burn scars

Wildfire-stripped slopes can't absorb rainfall — even modest storms produce dangerous flash floods on burned watersheds for years afterward.

Safety

Flood preparedness checklist

Floodwaters rise faster than most people expect. The basics that save lives.

1
Never drive through floodwaterSix inches can stall a car; two feet floats most vehicles. Turn around — don't drown.
2
Monitor levels near youTrack the gauges upstream of your location. Snoflo's push alerts can ping you the moment a threshold is crossed.
3
Have an evacuation planKnow two routes out and where higher ground sits. If officials issue an evacuation order, leave — don't wait.
4
Move valuables upDocuments, electronics, and sentimentals to upper floors. Disconnect electrical at the main breaker if water enters the structure.
5
Trust official sourcesNWS warnings and local emergency management are the authoritative source. Snoflo data is informational; always cross-check.
6
After the water recedesDon't return until officials clear the area. Floodwater carries sewage, fuel, and downed power. Document damage before cleanup.
Frequently asked

Flood map & river monitoring FAQ

What does "percent of normal" mean?

The current flow at a gauge compared to its seasonal average for this date. 100% means flow is right at the historical norm. 200%+ means twice the typical flow — a strong indicator of flood conditions on small-to-medium rivers. Every gauge-level flow report shows its live percent-of-normal.

What's the difference between a flood watch and a flood warning?

Watch: conditions are favorable for flooding within the next 12–48 hours. Warning: flooding is happening or imminent. Both come from the National Weather Service. Snoflo overlays both as toggleable layers on the map above.

How often does Snoflo's data refresh?

USGS streamgauge readings update every 15 minutes; we re-pull every hour. NWS warning polygons update as the NWS issues them — usually within 5 minutes. FEMA flood zones are static (the National Flood Hazard Layer is updated quarterly).

What is the FEMA flood zone layer?

FEMA's National Flood Hazard Layer (NFHL) shows the 1%-annual-chance ("100-year") and 0.2%-annual-chance ("500-year") floodplains. These are based on long-term hydrologic modeling, not current conditions. Useful for property risk; not a real-time signal.

Can I get an alert when my local river floods?

Yes. Save any USGS gauge as a favorite in the Snoflo iOS app, set a threshold (e.g. "alert me at 20 ft stage"), and you'll get a push the moment it crosses. Free with a Snoflo account.

Is Snoflo a substitute for official warnings?

No. Snoflo is informational. For life-safety decisions always follow guidance from local emergency management, the NWS, and law enforcement.

Stay ahead of the water

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