Atlantic Coast at Dennis Sesuit Harbor (IN MLLW)
Massachusetts — Water Level & Flood Stage
Located in Barnstable County, Massachusetts 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: SESM3). Live data may be limited. View on NWS AHPS →
Flood Stages
Major Flood
16 ft
Moderate Flood
14.5 ft
Minor Flood
13 ft
Action Stage
12 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
16 ft
This is a serious and life threatening flood. Extensive flooding more than 3 feet deep occurs along the Cape Cod Bay shore from Sandwich through Dennis and Brewster. Low lying roads, including parts of Route 6A, are impassable. Buildings near Sandwich Harbor and some buildings around Town Neck Beach are flooded or surrounded by floodwaters. The Sandwich Boardwalk, Marina, and Harbormaster's Shack become flooded. Follow the instructions of local officials and evacuate if asked to do so.
15 ft
Flooding 2 to 3 feet deep affects many low lying areas including shoreline roads along Cape Cod Bay from Sandwich through Dennis and Brewster. Some low lying homes and roadways becoming surrounded or inundated by deep floodwaters. Parts of Route 6A become impassable. Follow the instructions of local officials and evacuate if asked to do so.
14 ft
Some shoreline roads are impassable including River Street in Sandwich and a part of Route 6A in Dennis and Brewster. Flooding 1 to 3 feet deep encroaches, and in some cases, surrounds low lying homes along Cape Cod Bay in Sandwich, Brewster, and Dennis.
13 ft
Flooding up to one foot deep affects low lying sections along Cape Cod Bay. Somevulnerable coastal roads may impassable for a short time around high tide.
12 ft
Shallow pockets of flooding less than one foot deep affect low lying areas along Cape Cod Bay. Some shoreline roads may be flooded for a short time around high tide from splashover from rough surf.
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 |
|---|---|---|
| Jan 26, 2015 | 16.38 ft | — |
| Jan 26, 2015 | 16.38 ft | — |
| Jan 3, 2018 | 16.12 ft | — |
| Jan 3, 2018 | 16.12 ft | — |
| Mar 2, 2018 | 15.21 ft | — |
About This Gauge
NWS LID
SESM3
River
Atlantic Coast
County
Barnstable, MA
Coordinates
41.7519°N, 70.1539°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 Dennis Sesuit Harbor (IN MLLW)?
The Atlantic Coast at Dennis Sesuit Harbor (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 Dennis Sesuit Harbor (IN MLLW)?
The NWS-defined flood stage for Atlantic Coast at Dennis Sesuit Harbor (IN MLLW) is 13 feet. Action stage begins at 12 feet. Moderate flooding starts at 14.5 feet, and major flooding at 16 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 Dennis Sesuit Harbor (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 Dennis Sesuit Harbor (IN MLLW) gauge located?
The gauge is located in Barnstable County, Massachusetts at coordinates 41.7519°N, 70.1539°W. Data is provided by the U.S. Geological Survey and the National Weather Service.
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Source & Notes
Data provided by: US Geological Survey
- <span style="color: #ff0000;">Please refer to our <span style="background-color: #ffff00;"><a style="color: #ff0000; background-color: #ffff00;" title="Link to CFWBOX" href="https://forecast.weather.gov/product.php?site=NWS&issuedby=BOX&product=CFW&format=CI&version=1&glossary=0">Coastal Hazard Message</a></span> for specific information regarding Coastal Flood Watches, Warnings and Advisories. Actual impacts from any coastal flooding event may vary due to factors such as rainfall, wave action, and the number of tide cycles during which there is an onshore flow. During tropical cyclones, please refer <span style="background-color: #ffff00;"><a style="background-color: #ffff00;" title="Link to TCVBOX" href="https://forecast.weather.gov/product.php?site=NWS&issuedby=BOX&product=TCV&format=CI&version=1&glossary=1">here</a></span> for additional storm surge information.</span>
- <span style="color: #ff0000;">During a Tropical Storm or Hurricane Watch or Warning, inundation mapping provided by the <span style="background-color: #ffff00;"><a style="color: #ff0000; background-color: #ffff00;" href="https://www.nhc.noaa.gov">National Hurricane Center</a></span> (go to the web site and select the storm of interest) reflects a reasonable worst case scenario. The forecast above is the total water forecast that is most likely to occur.</span>