Rivers in Pennsylvania
West Branch Susquehanna River at Williamsport
Below flood stage
2.93ftStage
Observed Mon, Sep 28, 5:15 AM EDT
- Flood stage
- 20.00 ft
- Forecast crest
- 2.80 ftMon, Sep 28, 8:00 AM EDT
- Record crest
- 34.75 ft1972
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 30.00 ft |
| Moderate flood | 21.00 ft |
| Minor flood | 20.00 ft |
| Action | 10.00 ft |
- 45.00 ftFlood waters begin to reach the Market Street Bridge in Williamsport.
- 41.00 ftFEMA 0.2% Annual Chance Flood Level (500-year flood).
- 34.70 ftFlood of record from Hurricane Agnes in 1972. FEMA 1% Annual Chance Flood Level (100-year flood).
- 34.00 ftWidespread flooding occurs in areas not protected by the levee system.
- 33.00 ftFlood waters begin to reach the Arch Street Bridge in Williamsport.
- 32.00 ftWidespread flooding occurs in areas not protected by the levee system. The protective works for Route 220 are closed at this level. Flood waters begin to reach the Maynard Street Bridge in Williamsport.
- 31.50 ftFEMA 2% Annual Chance Flood Level (50-year flood).
- 30.00 ftMany homes and businesses outside the levee system are affected by high water.
- 23.00 ftLow lying areas on both banks are inundated. FEMA 10% Annual Chance Flood Level (10-year flood).
- 21.00 ftA number of residences and roads in the area outside the levee system are affected.
- 20.00 ftHigh water affects a few homes and some roadways in areas not protected by the levee system. The camping area west of Williamsport is significantly affected.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | 10% |
| Moderate flooding | 8% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 28, 2026.
Crest history
27 crests on NOAA’s list since 1865.
| # | Date | Stage |
|---|---|---|
| 1 | June 23, 1972 | 34.75 ft |
| 2 | March 18, 1936 | 33.57 ft |
| 3 | June 1, 1889 | 32.40 ft |
| 4 | May 21, 1884 | 31.00 ft |
| 5 | May 28, 1946 | 29.60 ft |
| 6 | November 26, 1950 | 28.10 ft |
| 7 | September 18, 2004 | 27.82 ft |
| 8 | March 17, 1865 | 27.50 ft |
| 9 | March 11, 1964 | 27.25 ft |
| 10 | January 20, 1996 | 26.71 ft |
| 11 | February 15, 1984 | 25.60 ft |
| 12 | September 26, 1975 | 24.70 ft |
| 13 | March 12, 1936 | 23.70 ft |
| 14 | December 2, 2010 | 23.25 ft |
| 15 | June 23, 1959 | 23.00 ft |
| 16 | December 31, 1942 | 23.00 ft |
| 17 | March 6, 1979 | 22.73 ft |
| 18 | April 1, 1940 | 22.70 ft |
| 19 | February 26, 1961 | 21.68 ft |
| 20 | September 11, 2018 | 21.08 ft |
| 21 | April 1, 1960 | 20.92 ft |
| 22 | April 2, 1993 | 20.52 ft |
| 23 | March 6, 1964 | 20.40 ft |
| 24 | April 28, 2011 | 20.27 ft |
| 25 | August 19, 1994 | 19.66 ft |
Most recent crests
- September 11, 2018: 21.08 ft
- April 28, 2011: 20.27 ft
- December 2, 2010: 23.25 ft
- September 18, 2004: 27.82 ft
- January 20, 1996: 26.71 ft
- August 19, 1994: 19.66 ft
- November 28, 1993: 18.91 ft
- April 2, 1993: 20.52 ft
- April 6, 1984: 19.04 ft
- February 15, 1984: 25.60 ft
Nearby
Upstream, downstream and the gauges around this one.
- UpstreamWest Branch Susquehanna River at Jersey Shore
- DownstreamWest Branch Susquehanna River at Muncy
- Lycoming Creek at Williamsport
- Lycoming Creek at Hepburnville
- Loyalsock Creek at Loyalsockville
- West Branch Susquehanna River at Allenwood
- Larrys Creek at Salladasburg
- Lycoming Creek at Trout Run (Camp Susque)
- Muncy Creek at Muncy Creek
What this means
Forecasts by the Middle Atlantic River Forecast Center. Forecasts are issued routinely year-round. Gauge reading may be affected by ice. Forecast flows are unadjusted for ice.
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.