StormCast — Weather & Emergency Alerts

Great South Bay at Watch Hill (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 01305575, updated every 15 minutes.

Current Water Level

Gage Height

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Streamflow

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Last Reading

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Flood Stages

Major Flood

4.2 ft

Moderate Flood

3.7 ft

Minor Flood

3.2 ft

Action Stage

2.8 ft

Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.

7-Day Water Level Chart

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View Official NWS Hydrograph →

Historic Crests

Date Stage Flow
Oct 28, 20127.73 ft
Oct 28, 20127.73 ft
Nov 7, 20124.14 ft
Nov 7, 20124.14 ft

About This Gauge

USGS Site

01305575

NWS LID

FIRN6

River

Great South Bay

County

Suffolk, NY

Coordinates

40.6914°N, 72.9897°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.

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Frequently Asked Questions

What is the current water level of Great South Bay at Watch Hill (IN MLLW)?

The Great South Bay at Watch Hill (IN MLLW) gauge is maintained by USGS (site 01305575) 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 Watch Hill (IN MLLW)?

The NWS-defined flood stage for Great South Bay at Watch Hill (IN MLLW) is 3.2 feet. Action stage begins at 2.8 feet. Moderate flooding starts at 3.7 feet, and major flooding at 4.2 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 Watch Hill (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 Watch Hill (IN MLLW) gauge located?

The gauge is located in Suffolk County, New York at coordinates 40.6914°N, 72.9897°W. USGS site number: 01305575. 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, Observations courtesy of U.S. Geological Survey