Atlantic Coast at Seavey Island (IN MLLW)
New Hampshire — Water Level & Flood Stage
Located in York County, New Hampshire on the Atlantic Coast. Live water level data from USGS, updated every 15 minutes.
Current Water Level
Gage Height
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Streamflow
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Last Reading
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This is an NWS forecast point (LID: SEIM1). Live data may be limited. View on NWS AHPS →
Flood Stages
Major Flood
13.5 ft
Moderate Flood
12.5 ft
Minor Flood
11.5 ft
Action Stage
10 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
13.5 ft
Record flooding. Expect inundation of roads and buildings along the waterfront and back bays that has never occurred in previous events. Several vulnerable coastal roads inundated with several feet of water. Route 1 in Portsmouth inundated near Sagamore Creek. Route 1B inundated in multiple locations on all access points to New Castle.
13 ft
Near flood of record with major widespread coastal flooding expected. Numerous buildings inundated along Portsmouth waterfront and the North Mill Pond area. Residential roads in Kittery flooded, isolating neighborhoods. Route 1B on the causeway and Wentworth Road leading to New Castle are most imapcted.
12.5 ft
Flooding impacts roads in New Castle with water approaching the 1B causeway and Wentworth Road.
12 ft
Moderate flooding of low lying coastal areas in Kittery, Portsmouth, New Castle, and Newington. Flooding expands in Portsmouth with numerous streets inundated along the waterfront. Some commercial and residential buildings in Portsmouth and Kittery impacted.
11.5 ft
Flooding impacts Ceres and Mechanic Street in Portsmouth.
11 ft
Minor flooding of low lying coastal locations in Kittery, Portsmouth, New Castle, and Newington. Vulnerable waterfront pier locations, low lying causeways, and roads could see up to 1 foot of inundation.
Impact statements from the National Weather Service, describing what typically happens at each water level.
7-Day Water Level Chart
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Historic Crests
| Date | Stage | Flow |
|---|---|---|
| Dec 23, 2022 | 12.41 ft | — |
| Dec 23, 2022 | 12.41 ft | — |
About This Gauge
NWS LID
SEIM1
River
Atlantic Coast
County
York, NH
Coordinates
43.0798°N, 70.7411°W
Get Flood Alerts for Atlantic Coast
StormCast monitors this gauge and sends a push notification to your phone when the water level crosses into a new flood category — even at 3 AM.
Frequently Asked Questions
What is the current water level of Atlantic Coast at Seavey Island (IN MLLW)?
The Atlantic Coast at Seavey Island (IN MLLW) gauge is maintained by USGS and reports water levels every 15 minutes. Visit this page to see the latest reading updated live, or download StormCast to get push alerts when levels rise.
What is flood stage for Atlantic Coast at Seavey Island (IN MLLW)?
The NWS-defined flood stage for Atlantic Coast at Seavey Island (IN MLLW) is 11.5 feet. Action stage begins at 10 feet. Moderate flooding starts at 12.5 feet, and major flooding at 13.5 feet.
How do I get alerts when Atlantic Coast rises?
Download StormCast free on Google Play, go to River Gauges, and add Atlantic Coast at Seavey Island (IN MLLW) to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category — even when your screen is off.
Where is the Atlantic Coast at Seavey Island (IN MLLW) gauge located?
The gauge is located in York County, New Hampshire at coordinates 43.0798°N, 70.7411°W. Data is provided by the U.S. Geological Survey and the National Weather Service.
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Source & Notes
- <style type="text/css"> .style1 {background-color: #FFFF00;}</style>Please refer to our <style type="text/css"> .style1 { background-color: #FFFF00;} .style2 {background-color: #FFFF00;} </style> <a href="http://forecast.weather.gov/product.php?site=NWS&issuedby=PHI&product=CFW&format=CI&version=1&glossary=0"> <span class="style1">Coastal Hazard Message</span></a> for specific information regarding Coastal Flood Watches, Warnings and Advisories. During tropical cyclones, please refer<a href="https://forecast.weather.gov/product.php?site=NWS&issuedby=PHI&product=TCV&format=CI&version=1&glossary=1"> <span class="style2">here</span></a> for additional storm surge information.
- Coastal flood impacts are dependent upon waves as well as tide level. High waves can result in flooding even if the tide level is below flood stage.