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Maine River Levels

Maine rivers do their flooding in the cool half of the year, when rain lands on ground that cannot absorb it. Here are 6 Maine gauges read live from USGS against the flood stages NWS established for each, the live NWS alert feed, and the months the record says to watch.

Maine rivers normally run highest in April and May, on cool season rain
Gauges read live here
6
NWS forecast points
5
Record crest, kennebec river
26.4 ft
Biggest drainage watched
7,884 sq mi
Right now, from the agencies

Where Maine rivers stand against their flood stages

Each card below carries two numbers from two agencies: the stage USGS is reporting at the gauge right now, read live from waterservices.usgs.gov when this page loaded, and the flood stage NWS has established for that same gauge. The “above” or “below” line is the subtraction between them and nothing more. A gauge below its thresholds is exactly that, not a promise about the next storm.

Live: USGS stage vs the NWS flood stage for each gauge
6 river gauges in Maine

Reading current stage from waterservices.usgs.gov.

Stages are the U.S. Geological Survey's own readings, fetched live in your browser and shown without adjustment; provisional data are marked and may be revised by USGS. The action, minor, moderate and major thresholds are established per gauge by the National Weather Service and were snapshotted from the National Water Prediction Service; “above” or “below flood stage” is arithmetic on those two agency numbers and nothing more. A reading describes the gauge's own reach, not any particular property near it. Sources: USGS and NWS NWPS

Make it local

Find the gauges nearest you

Every reading on this page belongs to one gauge on one reach of river, and the gauge nearest you is the one describing your water. This tool ranks the Maine gauges on this page (and, where the state line is closer than the water, the rest of the site's registry) by distance from a ZIP code, with each gauge's live stage against its flood stage. The distance is printed on every row because a gauge 40 miles away describes that river, not your street.

The warnings themselves

Active NWS flood products for Maine

Gauges show water that has already arrived. Warnings arrive first, and they cover the thousands of Maine streams that have no gauge at all, which is where flash floods do their killing. This feed is read live from api.weather.gov and republished exactly as NWS issued it.

Live: NWS flood products for Maine

Reading active alerts from api.weather.gov.

Republished as issued by the National Weather Service, read live from api.weather.gov when this page loaded. Coastal and lakeshore flood products are not listed here; find them with everything else at weather.gov.

The product names have precise meanings. A Flood Warning, in NWS's words, is “a release by the NWS to inform the public of flooding along larger streams in which there is a serious threat to life or property”. A Flash Flood Warning means flash flooding is in progress, imminent, or highly likely: act first, check the river later.

The scale everything runs on

What flood stage means at each Maine gauge

Flood stage is not one number. NWS establishes a ladder of thresholds for each individual gauge, in feet of stage at that gauge, because the same depth of water means different things in different valleys. Here is Maine's committed ladder, then the agency's own definitions of each rung.

GaugeCountyActionFloodModerateMajorRecord crest
Penobscot River at Bangor, MainePenobscot11 ft11.6 ft13 ft15 ft17.9 ft (1976)
St. John River below Fish River, near Fort Kent, MaineAroostook18 ft22.5 ft24.5 ft26.5 ft30.1 ft (2008)
Androscoggin River at Rumford, MaineOxford11 ft13.5 ft17 ft19 ft24 ft (1936)
St. Croix River at Baring, MaineWashington11 ft12 ft12.5 ft13 ft12.8 ft (1961)
Mattawamkeag River near Mattawamkeag, MainePenobscot13 ft13.5 ft16 ft17.5 ft16.3 ft (2014)
Kennebec River at Gardiner, MaineKennebec12 ft13 ft15 ft17 ft26.4 ft (1936)

Thresholds are the National Weather Service's established gage heights for each point, snapshotted from the National Water Prediction Service on 2026-09-02; they change rarely. “None set” means NWS has not established that category for the gauge, which is common at remote points. Record crests are NWS's own historic crest listings.

Action stageThe heads up level. Nothing is flooding, and the people whose job it is to watch the river have started watching it.

“The stage which, when reached by a rising stream, represents the level where the NWS or a partner/user needs to take some type of mitigation action in preparation for possible significant hydrologic activity. The appropriate action is usually defined in a weather forecast office (WFO) hydrologic services manual.”

National Weather Service Glossary, Action Stage
Flood stage (minor flooding)Where flooding officially begins for this gauge. Water is out of the banks somewhere in the reach, usually in low spots first.

“Minor Flooding is defined to have minimal or no property damage, but possibly some public threat. A FLOOD ADVISORY product is issued to advise the public of flood events that are expected not to exceed the minor flood category.”

National Weather Service, High Water Level Terminology
Moderate flood stageBuildings and roads near the river are taking water and some people are moving out of the way.

“Moderate Flooding is defined to have some inundation of structures and roads near the stream. Some evacuations of people and/or transfer of property to higher elevations may be necessary. A FLOOD WARNING should be issued if moderate flooding is expected during the event.”

National Weather Service, High Water Level Terminology
Major flood stageExtensive inundation. The stage at which a flood becomes the event a town remembers by year.

“Major Flooding is defined to have extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations are necessary. A FLOOD WARNING should be issued if major flooding is expected during the event.”

National Weather Service, High Water Level Terminology

The threshold names and definitions are the National Weather Service's; the one line glosses above each quote are ours.

“Flood categories are terms defined for each gage location that describe or categorize the observed or expected severity of flood impacts in the corresponding stream segment or nearby stream. The severity of flooding at a given stage is not necessarily the same at all locations along a stream due to varying channel/bank characteristics on portions of the stream.”

National Weather Service, High Water Level Terminology

What NWS says happens at these stages, in its own words

For 6 of these gauges, NWS publishes impact statements: sentences tied to specific stages, naming the roads and places that go under. They are the most local flood information that exists for these reaches, they are federal writing republished verbatim, and they are exactly what the thresholds above are made of.

Penobscot River at Bangor, Maine

at 12 ft

“Bangor Waterfront begins to flood in portions of the riverwalk. Flood control systems and barriers in Kenduskeag Plaza may become stressed.”

NWS impact statement, National Water Prediction Service
at 21.5 ft

“Comparable to the FEMA 0.2 percent flood level. State Road in Bangor flooded north of the hospital. This is an extremely dangerous and life threatening situation. Transportation, communications, water and power severely affected.”

NWS impact statement, National Water Prediction Service

St. John River below Fish River, near Fort Kent, Maine

at 22.5 ft

“Lumber Yard near Fort Kent State Historic Site floods. Flood waters encroach on the State Historic Site.”

NWS impact statement, National Water Prediction Service
at 29.7 ft

“Dike along the Saint John River is overtopped, flooding downtown Fort Kent from Pearl Street to Blockhouse Road to Elm Street. Significant flooding of Residential and Commercial Structures between the Fish River to Market Street along East Main Street.”

NWS impact statement, National Water Prediction Service

Androscoggin River at Rumford, Maine

at 13.5 ft

“One lane of Route 140 inundated in Jay. Flooding occurs at the ballfield south of Lincoln Avenue in Rumford.”

NWS impact statement, National Water Prediction Service
at 25 ft

“Unprecedented and historic level approximately equivalent to a 500 year flood. Devastating flooding occurs from Bethel to Rumford and Peru.”

NWS impact statement, National Water Prediction Service
The calendar

Why Maine floods in the cool season

The rivers on this page do their rising between late fall and mid spring. The mechanism is the ground, not just the sky: rain that would soak in harmlessly during the growing season runs straight off soil that is dormant, frozen, thawing or already full, and in our reduction of USGS's own daily medians the high months here are April and May. Summer can still flood Maine; it just has to work harder.

Typical flow by month at St. John River below Fish River, near Fort Kent, Maine: for each month we average USGS's own published daily median discharge across that month, from the gauge's full daily record. Highest in May, lowest in February. The reduction is our arithmetic on USGS numbers, not a USGS product, and it describes a typical year rather than this one.
Typical flow by month at Androscoggin River at Rumford, Maine: for each month we average USGS's own published daily median discharge across that month, from the gauge's full daily record. Highest in April, lowest in September. The reduction is our arithmetic on USGS numbers, not a USGS product, and it describes a typical year rather than this one.

The deepest water on this page's record: 26.4 feet at Kennebec River at Gardiner, Maine in 1936, which is 13.4 feet above that gauge's flood stage. NWS keeps the crest lists, and its definition is the useful one here:

“Record flooding is flooding that equals or exceeds the highest stage or discharge at a given site during the period of record keeping.”

National Weather Service, High Water Level Terminology
A river running brim full against a downtown floodwall walkway in late fall light
The Skagit River brim full against the Mount Vernon floodwall in November 2021. Rain that would soak in harmlessly in September runs straight off dormant or saturated ground, which is why the crests on record in cool season states cluster in the cool half of the year. “Skagit River flooding in downtown Mount Vernon, WA - Nov 17, 2021” by SounderBruce, CC BY-SA 4.0
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The part no gauge can do

NWS flood safety, quoted verbatim

Most Maine streams have no gauge, and flash floods happen on exactly that water. NWS says both halves of this plainly, and its words belong on this page more than any reading does.

First, who dies in floods, from the agency that counts:

“Each year, more deaths occur due to flooding than from any other thunderstorm related hazard. The Centers for Disease Control and Prevention report that over half of all flood-related drownings occur when a vehicle is driven into hazardous flood water. The next highest percentage of flood-related deaths is due to walking into or near flood waters.”

National Weather Service, Turn Around Don't Drown

“A mere 6 inches of fast-moving flood water can knock over an adult. It takes just 12 inches of rushing water to carry away most cars and just 2 feet of rushing water can carry away SUVs and trucks. It is NEVER safe to drive or walk into flood waters.”

National Weather Service, Turn Around Don't Drown

“Never drive around the barriers blocking a flooded road. The road may have collapsed under that water.”

National Weather Service, Turn Around Don't Drown

Those three passages are the NWS Turn Around Don't Drown campaign in full working order, and they apply to every water crossing in Maine, gauged or not. Second, the limits of pages like this one. NWS, writing about the state with more rivers and fewer gauges than any other, is candid about the network:

“There are uncountable numbers of streams and lakes of various sizes in Alaska and only a very small fraction of these have gages that monitor the water levels.”

National Weather Service, High Water Level Terminology

“People living or recreating near any stream or lake should identify the closest gage that can be used as an index for the expected water level changes at their location.”

National Weather Service, High Water Level Terminology

That is the frame for everything above: a gauge is an index for its reach, the nearest one is worth knowing, and a Flash Flood Warning outranks any reading on this page. The NWS definition that makes the speed clear:

“A rapid and extreme flow of high water into a normally dry area, or a rapid water level rise in a stream or creek above a predetermined flood level, beginning within six hours of the causative event (e.g., intense rainfall, dam failure, ice jam). However, the actual time threshold may vary in different parts of the country. Ongoing flooding can intensify to flash flooding in cases where intense rainfall results in a rapid surge of rising flood waters.”

National Weather Service Glossary, Flash Flood

Flood zones are FEMA's to determine. Whether a property sits in one is an official determination tied to flood insurance, and it is made on FEMA's own maps. In FEMA's own words:

“The FEMA Flood Map Service Center (MSC) is the official public source for flood hazard information produced in support of the National Flood Insurance Program (NFIP). Use the MSC to find your official flood map, access a range of other flood hazard products, and take advantage of tools for better understanding flood risk.”

FEMA Flood Map Service Center

Look up any address at msc.fema.gov.

Where these numbers come from

Where the Maine figures come from

Two agencies, kept apart. The readings are live from USGS: stage from the instantaneous values service, discharge and its percentile context from the same daily services the drought pages use. The thresholds, impact statements and crests are NWS's, snapshotted from the National Water Prediction Service on 2026-09-02; flood stages are established gage heights that change rarely, and the snapshot date is printed wherever they appear. The alerts are live from api.weather.gov.

Which gauges appear is our choice, made once and stated plainly: active USGS stage gauges that NWS resolves to a forecast point with a published flood stage, ranked by drainage area so the rivers people actually check come first, at most two per river, spread across the state, with canals and diversions excluded. Gauges below dams are kept on purpose: regulated or not, they are the gauges downstream towns watch. The thing that is missing on purpose: there is no flood score, index or rating of ours anywhere on this site, and no flood zone map either. NWS owns the thresholds, USGS owns the readings, FEMA owns the maps.

Sources: USGS Water Data for the Nation, NWS National Water Prediction Service, NWS flood safety, and FEMA Flood Map Service Center.

A note on what the National Water Prediction Service is, in our words. It is the NWS platform that carries every official river gauge page: observed stages, forecast crests where a river forecast center issues them, the flood stage ladder, impact statements and historic crests. When a reading on this page makes you want a second opinion, the NWPS gauge page linked on every card is the authoritative one.

Our summary of information published by NWS National Water Prediction Service

A small concrete streamgage station with a solar panel beside a forest creek and weir
A USGS streamgage: the instrument every number on this page starts from. The stilling well and weir turn a creek into a measurement, and stations like this one report the stage that the NWS thresholds are established against. “USGS Streamgage” — U.S. Geological Survey — Public domain
Common questions

Maine river levels FAQ

Keep reading

The same water, other seasons

River levels in nearby states

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Stage and discharge readings are the U.S. Geological Survey's, read live in your browser and shown without adjustment. Flood stage thresholds, impact statements and historic crests are the National Weather Service's, snapshotted from the National Water Prediction Service and dated where they appear. Alerts are republished as NWS issued them. Flood zone determinations are FEMA's alone. This page is a state level index: cool season high water is a fact about the gauges above (Maine's biggest watched gauge sits under the 93,000 square mile line), not about any address. National picture: river levels in every state