St. Marys River at Decatur water level

Name: St. Marys River at Decatur water level (U.S. Geological Survey)
Creator: U.S. Geological Survey
License: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits

River gauge, St. Marys River, Indiana, United States

Directions

Below flood stage

Water level

3.25ft Steady over the last 24 hours

Measured Oct 20, 2026, 08:25 AM EDT (47 min ago)

Flow: 71.9 cfs

History

7 days

Water level Minor flood stage

What this means

Water levels are unremarkable at St. Marys River at Decatur, where the gauge shows 3.25 ft.

It is 13.75 ft below the flood stage of 17.00 ft.

The level has held steady over the past 24 hours. The 30-day range is 3.22 ft – 3.41 ft.

Fall is often low-water season on rivers, until steadier rain returns.

Judged against the official flood stage for this gauge. How to read levels

Key numbers

Highest on record: 26.92 ftJuly 9, 2003

Paddling and fishing conditions

Most paddlers and anglers will find the river in good shape at this stage.

For reference, flood stage is 17.00 ft.

What happens at each level

30.60 ft: Flood water begins to hit the bottom of the bridge at the gage site.
27.50 ft: Flood water reaches the 100 year flood level.
26.50 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.
24.50 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.
23.50 ft: Many east side city streets and county roads are flooded. Evacuation of east side residents near Bellmont High School becomes necessary.
23.00 ft: Portions of Ohio Routes 33, 49 and 81 are closed near Willshire.
22.50 ft: Piqua Road begins to flood at Decatur. Evacuations begin on Ogg Street. Ohio State Route 49 near Willshire becomes flooded.
21.50 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.
20.50 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.
19.50 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.
18.80 ft: Flood water begins to cross Ohio Highway 49 north of Willshire, Ohio.
18.50 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.
3.25 ft: Right now

Impact statements from the U.S. National Weather Service.

Highest crests on record

Chance of at least minor flooding in October to December: 24 %.

Rank	Level	Date
1	26.92 ft	July 9, 2003
2	25.11 ft	June 18, 2015
3	24.40 ft	March 14, 1982
4	24.31 ft	February 25, 1985
5	24.22 ft	February 10, 1959
6	24.20 ft	January 14, 2005
7	24.13 ft	July 17, 1992
8	23.81 ft	December 31, 1990
9	23.60 ft	February 8, 2008
10	23.60 ft	February 15, 1950

Weather at the gauge

No rain in the last 3 days.

20 Tue 63° 35° – Wind 7 mph

21 Wed 64° 38° – Wind 6 mph

22 Thu 68° 49° – Wind 5 mph

23 Fri 67° 48° – Wind 7 mph

24 Sat 69° 48° – Wind 7 mph

25 Sun 71° 51° – Wind 11 mph

26 Mon 70° 55° – Wind 15 mph

Forecast: Open-Meteo

Sunrise 07:57 AM Sunset 06:53 PM Daylight 10 hr, 56 min First quarter 68%

Map

Other gauges on the St. Marys River

Gauge	Level	Compared with normal	24 hours	Distance
St. Marys River at Rockford OHRiver gauge, St. Marys River	1.66 ft	Below flood stage	±0	19 mi
St. Marys River at Pleasant MillsRiver gauge, St. Marys River	51.3 cfs	Normal	−1.9 cfs	7 mi
St. Marys River near Fort WayneRiver gauge, St. Marys River	1.14 ft	Below flood stage	−0.03 ft	13 mi
St. Marys River at Main St. at Fort WayneRiver gauge, St. Marys River	78.6 cfs	Normal	−21.2 cfs	20 mi

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
St Marys River at Walcot Street at Willshire OHRiver gauge, St Marys River	38.0 cfs	Normal	±0	10 mi
Wabash River at BlufftonRiver gauge, Wabash River	1.82 ft	Below flood stage	−0.01 ft	14 mi
Wabash River at Linn GroveRiver gauge, Wabash River	4.94 ft	Below flood stage	−0.05 ft	15 mi
Maumee River at New HavenRiver gauge, Maumee River	3.35 ft	Below flood stage	−0.08 ft	17 mi
Maumee River at Fort WayneRiver gauge, Maumee River	2.03 ft	Below flood stage	−0.06 ft	19 mi
Junk Ditch at Fort WayneCanal gauge, Junk Ditch	0.5 cfs	Normal	−0.9 cfs	20 mi

Questions and answers

What is flood stage for the St. Marys River at Decatur?

The official flood stage is 17.00 ft. The level is currently 13.75 ft below it.

Is gage height the same as water depth?

No. Gage height is measured from a fixed reference point chosen by the agency, so a reading of 10 ft does not mean the river is 10 ft deep.

What is the water level of St. Marys River at Decatur today?

On Oct 20, 2026, 08:25 AM EDT, the water level was 3.25 ft. Steady over the last 24 hours.

Is St. Marys River at Decatur rising or falling?

Steady over the last 24 hours.

Is the level of St. Marys River at Decatur normal?

Below flood stage. Judged against the official flood stage for this gauge.

What is the highest water level ever recorded at St. Marys River at Decatur?

The highest level on record is 26.92 ft on July 9, 2003.

How often is this data updated?

The U.S. Geological Survey publishes a new reading every 15 minutes. This page refreshes within minutes of each update.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: U.S. Geological Survey
Station code: usgs:04181500 (Agency page)
Coordinates: 40.84808, -84.93770 (WGS84)
Vertical datum: NAVD88
Update interval: every 15 minutes
Licence: Public domain. Data: U.S. Geological Survey (USGS), provisional data subject to revision

Published series

Parameter	Last value	Time (UTC)	Quality
Water level	3.25 ft	2026-10-20 12:25	Provisional
Flow	71.9 cfs	2026-10-20 12:25	Provisional

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How to cite

U.S. Geological Survey: St. Marys River at Decatur (usgs:04181500). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/united-states/indiana/st-marys-river-at-decatur

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer