Atlantic Ocean at Matanzas River Inlet Bridge (in MHHW)
Florida — Water Level & Flood Stage
Located in St. Johns County, Florida on the Atlantic Ocean. 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: MTIF1). Live data may be limited. View on NWS AHPS →
Flood Stages
Major Flood
5 ft
Moderate Flood
3.5 ft
Minor Flood
2.5 ft
Action Stage
1.8 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
6 ft
Catastrophic flooding near Matanzas Inlet and along the Matanzas River. The approach road to State Road 206 on the mainland is flooded at this level, isolating access to Crescent Beach. Flooding of structures worsens along A1A north of the Matanzas Inlet, with several structures along the river flooding up to 2.5 feet deep.
5 ft
Considerable flooding near Matanzas Inlet and along the Matanzas River. Homes in Summer Haven not elevated are flooded or isolated by water. North of the inlet, A1A is impassible as far north as Crescent Beach. Most residences west of A1A are flooded, some up to 1.5 ft deep.
3.5 ft
Flood severity increases near Matanzas Inlet and along the Matanzas River. A1A north of the inlet begins to flood in several places. Water enters structures along the Matanzas River between the inlet and Crescent Beach.
3 ft
Flooding expands along the Matanzas River near the Windjammer Condominiums with numerous residences west of A1A starting to flood. The sidewalks along A1A also flood at this level in this area. Water begins to affect residential lots in Crescent Beach along Green Road.
2.5 ft
Water begins to flood the backyards of homes along the Matanzas River near the Windjammer Condominiums. Water floods around the Fort Matanzas National Monument. Flooding begins in the Fort Matanzas National Monument Inlet west parking lot.
1.5 ft
Some of the marshland around Fort Matanzas National Monument area begin to flood.
Impact statements from the National Weather Service, describing what typically happens at each water level.
Low-Water Impacts
5 ft
Stage needed to inundate designated Gulf Sturgeon critical habitat below Jim Woodruff Lock and Dam.
3 ft
Temporary (not sustainable) operating level for of Scholz Power Plant
What happens as water levels drop, per the National Weather Service.
7-Day Water Level Chart
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Historic Crests
| Date | Stage | Flow |
|---|---|---|
| Oct 11, 2025 | 4.1 ft | — |
| Oct 11, 2025 | 4.1 ft | — |
| Oct 10, 2025 | 3.22 ft | — |
| Oct 10, 2025 | 3.22 ft | — |
| Sep 9, 2025 | 3.04 ft | — |
About This Gauge
NWS LID
MTIF1
River
Atlantic Ocean
County
St. Johns, FL
Coordinates
29.7047°N, 81.2278°W
Get Flood Alerts for Atlantic Ocean
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 Ocean at Matanzas River Inlet Bridge (in MHHW)?
The Atlantic Ocean at Matanzas River Inlet Bridge (in MHHW) 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 Ocean at Matanzas River Inlet Bridge (in MHHW)?
The NWS-defined flood stage for Atlantic Ocean at Matanzas River Inlet Bridge (in MHHW) is 2.5 feet. Action stage begins at 1.8 feet. Moderate flooding starts at 3.5 feet, and major flooding at 5 feet.
How do I get alerts when Atlantic Ocean rises?
Download StormCast free on Google Play, go to River Gauges, and add Atlantic Ocean at Matanzas River Inlet Bridge (in MHHW) 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 Ocean at Matanzas River Inlet Bridge (in MHHW) gauge located?
The gauge is located in St. Johns County, Florida at coordinates 29.7047°N, 81.2278°W. Data is provided by the U.S. Geological Survey and the National Weather Service.
More Resources
Source & Notes
Data provided by: Courtesy of Hohonu
- Water levels are referenced to the Mean Higher High Water (MHHW) Datum. This datum can be used to approximate sea water inundation of normally dry ground near the coast. For specific impacts, please refer to the statements on this page.