St. Marys River at Decatur
Indiana — Water Level & Flood Stage
Located in Adams County, Indiana on the St. Marys River. Live water level data from USGS gauge 04181500, 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
24 ft
Moderate Flood
20 ft
Minor Flood
17 ft
Action Stage
13 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
30.6 ft
Flood water begins to hit the bottom of the bridge at the gage site.
27.5 ft
Flood water reaches the 100 year flood level.
26.5 ft
Record flooding is in progress. Evacuations are necessary in Decatur, Indiana and Wilshire, Ohio. Serious flooding of the Central Soya Plant can be expected along with widespread flooding and disruption of land transportation.
24.5 ft
Major flooding is in progress with water at the top of the levee protecting the Central Soya Plant. US Highway 33 near Willshire, Ohio begins to flood. Extensive flooding of the east side of Decatur along with Bellmont High School occurs. Evacuations become necessary.
23.5 ft
Many east side city streets and county roads are flooded. Evacuation of east side residents near Bellmont High School becomes necessary.
23 ft
Portions of Ohio Routes 33, 49 and 81 are closed near Willshire.
22.5 ft
Piqua Road begins to flood at Decatur. Evacuations begin on Ogg Street. Ohio State Route 49 near Willshire becomes flooded.
21.5 ft
High water affects Piqua Rd...Ohio State Route 49 near the state line along with east side Decatur streets. Residential flooding begins on East Jackson and Ogg Streets. Bellmont High School grounds begin flooding.
20.5 ft
Indiana 101 north of Pleasant Mills is closed by flood water. Extensive agricultural flooding is in progress. Residents of the east and southeast side of Decatur become concerned.
19.5 ft
Flooding expands into more farm land in the Decatur area. Flood waters approach Piqua Road...Ohio State Route 49 and Indiana 101 just north of Pleasant Mills. Flood water begins to cross Ohio highway 49 north of Willshire, Ohio.
18.8 ft
Flood water begins to cross Ohio Highway 49 north of Willshire, Ohio.
18.5 ft
County Road 225 North...just north of Pleasant Mills Indiana is closed by flood water. Low land areas of Kekionga Park on the southeast side of Decatur begin flooding. Flooding is limited to farm land in Pleasant Mills Indiana and Willshire Ohio.
17.5 ft
County road 225 north of Pleasant Mills is flooded. Agricultural land flooding increases in northern...central and eastern Adams County.
17 ft
Agricultural flooding occurs along the river in northern...central and eastern Adams County.
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 |
|---|---|---|
| Jul 9, 2003 | 26.92 ft | 15,000 cfs |
| Jul 9, 2003 | 26.92 ft | 15,000 cfs |
| Jun 18, 2015 | 25.11 ft | 12,100 cfs |
| Jun 18, 2015 | 25.11 ft | 12,100 cfs |
| Mar 13, 1982 | 24.4 ft | 10,900 cfs |
About This Gauge
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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 St. Marys River at Decatur?
The St. Marys River at Decatur gauge is maintained by USGS (site 04181500) 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 St. Marys River at Decatur?
The NWS-defined flood stage for St. Marys River at Decatur is 17 feet. Action stage begins at 13 feet. Moderate flooding starts at 20 feet, and major flooding at 24 feet.
How do I get alerts when St. Marys River rises?
Download StormCast free on Google Play, go to River Gauges, and add St. Marys River at Decatur 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 St. Marys River at Decatur gauge located?
The gauge is located in Adams County, Indiana at coordinates 40.8481°N, 84.9377°W. USGS site number: 04181500. Data is provided by the U.S. Geological Survey and the National Weather Service.
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Source & Notes
Data provided by: the USGS (04181500), Observations courtesy of U.S. Geological Survey
- River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 48 hours into the future from the forecast issuance time.
- Stage may be affected by ice during winter months.