Major Flood
7.8 ft
Current Water Level
Gage Height
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Streamflow
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Last Reading
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FLOOD STAGES
Know the flood categories.
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
Moderate Flood
6 ft
Minor Flood
5 ft
What Floods at Each Level
8 ft
Along low lying portions of the Long Island Sound, two to three feet of inundation is possible a few blocks inland with one to two feet of inundation possible north of I-95 in several low spots around waterways such as the Niantic River in Niantic, the Mystic River in Mystic. Nearly fifteen miles inland along the Connecticut and Thames Rivers, inundation is also possible with major damage in regions such as West End Drive and Seaside Lane in Old Lyme.
6.5 ft
Inundation of one to two feet of water occurs on streets and several properties in Saybrook Point, as well as in the Marina where several feet of water is possible, as water reaches over the seawall.
6 ft
Coastal flooding causes Niantic River Road to close between 1st and 2nd Avenue.
5 ft
Flooding occurs in the downtown Mystic area directly along the waterfront, primarily in the street on Gravel Street and River Road. Groton experiences minor shoreline flooding.
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 |
|---|---|---|
| Sep 20, 1938 | 10.58 ft | — |
| Aug 30, 1954 | 9.58 ft | — |
| Oct 28, 2012 | 8.04 ft | — |
About This Gauge
USGS Site
NWS LID
NLHC3
River
Long Island Sound
County
New London, CT
Coordinates
41.3610°N, 72.0956°W
Get Flood Alerts for Long Island Sound
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 Long Island Sound near New London Harbor (IN MLLW)?
The Long Island Sound near New London Harbor (IN MLLW) gauge is maintained by USGS (site 8461490) 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 Long Island Sound near New London Harbor (IN MLLW)?
The NWS-defined flood stage for Long Island Sound near New London Harbor (IN MLLW) is 5 feet. Action stage begins at N/A feet. Moderate flooding starts at 6 feet, and major flooding at 7.8 feet.
How do I get alerts when Long Island Sound rises?
Download StormCast free on Google Play, go to River Gauges, and add Long Island Sound near New London 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.
Where is the Long Island Sound near New London Harbor (IN MLLW) gauge located?
The gauge is located in New London County, Connecticut at coordinates 41.3610°N, 72.0956°W. USGS site number: 8461490. Data is provided by the U.S. Geological Survey and the National Weather Service.
More Gauges on Long Island Sound
More Resources
Source & Notes
Data provided by: NOAA National Ocean Service, Observations courtesy of U.S. Geological Survey
- <head> <meta charset="utf-8"> <style type="text/css"> .style1 { background-color: #FFFF00; } </style> </head> Tide Forecasts are a total water level forecast referenced to mean lower low water. Please refer to <a href="http://forecast.weather.gov/product.php?site=NWS&product=CFW&issuedby=AKQ"><font color="#0000ff"><span class="style1">Coastal Flood Advisories and Warnings</span></font></a> for official water level forecasts during periods of coastal flooding. During tropical cyclones, please refer<span class="style1"> </span> <a href="https://forecast.weather.gov/product.php?site=NWS&issuedby=AKQ&product=TCV&format=CI&version=1&glossary=1"> <span class="style1">here</span></a> for additional storm surge information.