Rivers in Pennsylvania

Monongahela River at Elizabeth Lock and Dam

Allegheny County, PennsylvaniaNWS ELZP1USGS 03075070Moon Township office

Out of service
7.23ftStage

Observed Thu, Sep 24, 5:15 AM EDT

Flood stage
20.00 ft
Record crest
32.50 ft1936

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood26.00 ft
Moderate flood23.00 ft
Minor flood20.00 ft
Action16.50 ft
  1. 32.00 ftElizabeth immediately downstream of Lock 3 floods.
  2. 30.50 ftWater Street, First Street and Second Street in West Elizabeth flood. Flood waters are 4 to 5 feet deep in homes along Water Street.
  3. 27.00 ftSerious damage to homes and industries in West Elizabeth. Many roads flood.
  4. 25.60 ftWater reaches the first floor of numerous homes from the intersection of First and Border Streets north to the intersection of Mill and First streets in West Elizabeth.
  5. 24.05 ftWater levels reach the flood levels of the flood of July 30, 2017.
  6. 23.00 ftIndustrial Chemical Corporation plant floods.
  7. 22.00 ftIn West Elizabeth basements of numerous homes in the block bounded by First and Water streets begin to flood.
  8. 20.00 ftSmall communities around Lock 3 area begin minor flooding.
  9. 18.10 ftLock walls overtopped.
  10. 17.50 ftNavigation suspended, lock out of service.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor flooding17%
Moderate flooding8%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 22, 2026.

Crest history

51 crests on NOAA’s list since 1936.

#DateStage
1March 18, 193632.50 ft
2November 6, 198531.60 ft
3January 20, 199630.30 ft
4June 24, 197229.00 ft
5October 16, 195428.50 ft
6March 7, 196728.30 ft
7February 19, 200027.60 ft
8April 16, 200726.77 ft
9March 6, 196326.50 ft
10May 25, 196825.60 ft
11December 30, 194224.80 ft
12November 20, 200324.70 ft
13April 4, 202424.54 ft
14February 17, 201824.53 ft
15January 12, 197424.40 ft
16July 30, 201724.05 ft
17January 27, 197823.90 ft
18March 5, 201523.77 ft
19February 10, 199423.70 ft
20March 20, 196323.60 ft
21February 26, 197923.40 ft
22March 2, 202122.87 ft
23September 11, 201822.87 ft
24January 29, 199422.80 ft
25December 9, 197822.40 ft

Most recent crests

  • April 4, 2024: 24.54 ft
  • February 5, 2022: 20.17 ft
  • March 2, 2021: 22.87 ft
  • December 18, 2019: 20.05 ft
  • February 8, 2019: 18.10 ft
  • September 11, 2018: 22.87 ft
  • February 17, 2018: 24.53 ft
  • July 30, 2017: 24.05 ft
  • March 5, 2015: 18.43 ft
  • March 5, 2015: 23.77 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Ohio River Forecast Center. Forecasts are issued as needed during times of high water, but are not routinely available. Gauge readings unavailable - awaiting repair. Daily forecasts have been temporarily suspended. Forecasts will be issued as needed in times of high water. The above river forecast includes future rainfall/snowmelt. Forecast stages may be different if the actual rainfall/snowmelt is different than the forecast rainfall/snowmelt.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.