StormCast — Weather & Emergency Alerts

Mississippi River at Quincy Lock and Dam 21
Illinois — Water Level & Flood Stage

Located in Adams County, Illinois on the Mississippi River. 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: QLDI2). Live data may be limited. View on NWS AHPS →

Flood Stages

Major Flood

25 ft

Moderate Flood

21 ft

Minor Flood

18 ft

Action Stage

16 ft

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

What Floods at Each Level

140000 ft

At this approximate discharge, the Corps will raise the gates out of the water, creating "open river" conditions.

26.9 ft

Missouri Highway 168 east of Palmyra near the BASF plant closes near this height.

25.7 ft

At this height, the lock wall is inundated.

25 ft

Quincy Waterworks inundated.

21.9 ft

Near this level, the lock is closed to navigation. This level will vary with circumstance.

14 ft

Unprotected bottomlands flood.

12.3 ft

This is the upper limit of the target pool level at Lock and Dam 21.

12.2 ft

This is the target pool level for navigation at Lock & Dam 21.

12 ft

At some point between 11.6 to 12.1 feet, the Corps will lift all gates out of the river creating "open river" conditions, corresponding to an approximate discharge of 140,000 cfs.

11.8 ft

This is the lower limit of the target pool level at Lock & Dam 21.

Impact statements from the National Weather Service, describing what typically happens at each water level.

7-Day Water Level Chart

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View Official NWS Hydrograph →

Historic Crests

Date Stage Flow
Jul 12, 199331.3 ft428,694 cfs
Jul 12, 199331.3 ft428,694 cfs
Jun 1, 201930.15 ft
Jun 1, 201930.15 ft
Jun 18, 200829.58 ft476,900 cfs

About This Gauge

NWS LID

QLDI2

River

Mississippi River

County

Adams, IL

Coordinates

39.9022°N, 91.4303°W

Get Flood Alerts for Mississippi River

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 Mississippi River at Quincy Lock and Dam 21?

The Mississippi River at Quincy Lock and Dam 21 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 Mississippi River at Quincy Lock and Dam 21?

The NWS-defined flood stage for Mississippi River at Quincy Lock and Dam 21 is 18 feet. Action stage begins at 16 feet. Moderate flooding starts at 21 feet, and major flooding at 25 feet.

How do I get alerts when Mississippi River rises?

Download StormCast free on Google Play, go to River Gauges, and add Mississippi River at Quincy Lock and Dam 21 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 Mississippi River at Quincy Lock and Dam 21 gauge located?

The gauge is located in Adams County, Illinois at coordinates 39.9022°N, 91.4303°W. Data is provided by the U.S. Geological Survey and the National Weather Service.

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Source & Notes

Data provided by: US Army of Corps of Engineers