Great South Bay at West Sayville (IN MLLW)
New York — Water Level & Flood Stage
Located in Suffolk County, New York on the Great South Bay. Live water level data from USGS gauge 01306402, updated every 15 minutes.
Current Water Level
Gage Height
Loading...
Streamflow
Loading...
Last Reading
Loading...
Flood Stages
Major Flood
4.1 ft
Moderate Flood
3.6 ft
Minor Flood
3.1 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
13.1 ft
Inundation of one to three feet of water on the runways at LaGuardia Airport.
12.7 ft
Inundation of one to two feet on taxiways at LaGuardia Airport and in Douglaston Park.
10.8 ft
Inundation occurs on the FDR Drive in Manhattan. Elevated water levels on the East River force the water into catch basins and storm sewers and cause water to bubble and pour out of manholes on the northbound FDR Drive leading to road closures in the upper 80's and lower 90's. In Rye, inundation causes portions of Milton Road and Kirby Lane at the Tide Mill Basin to close.
10.2 ft
Minor coastal flooding in Port Washington along Shore Road, Sector Drive, and Sunset Park on Main Street.
10 ft
Milton Road and Kirby Lane in Rye close during high tide.
Impact statements from the National Weather Service, describing what typically happens at each water level.
7-Day Water Level Chart
Loading chart data...
Historic Crests
| Date | Stage | Flow |
|---|---|---|
| Sep 20, 1938 | 16.75 ft | — |
| Sep 20, 1938 | 16.75 ft | — |
| Aug 30, 1954 | 14.76 ft | — |
| Aug 30, 1954 | 14.76 ft | — |
| Oct 28, 2012 | 14.31 ft | — |
About This Gauge
USGS Site
NWS LID
SAYN6
River
Great South Bay
County
Suffolk, NY
Coordinates
40.7208°N, 73.0911°W
Get Flood Alerts for Great South Bay
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 Great South Bay at West Sayville (IN MLLW)?
The Great South Bay at West Sayville (IN MLLW) gauge is maintained by USGS (site 01306402) 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 Great South Bay at West Sayville (IN MLLW)?
The NWS-defined flood stage for Great South Bay at West Sayville (IN MLLW) is 3.1 feet. Action stage begins at N/A feet. Moderate flooding starts at 3.6 feet, and major flooding at 4.1 feet.
How do I get alerts when Great South Bay rises?
Download StormCast free on Google Play, go to River Gauges, and add Great South Bay at West Sayville (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 Great South Bay at West Sayville (IN MLLW) gauge located?
The gauge is located in Suffolk County, New York at coordinates 40.7208°N, 73.0911°W. USGS site number: 01306402. Data is provided by the U.S. Geological Survey and the National Weather Service.
More Gauges on Great South Bay
More Resources
Source & Notes
Data provided by: US Geological Survey, Observations courtesy of U.S. Geological Survey
- Gauge awaiting repair - automated readings are not available at this time.