January 1996 Flash Flood in the Susquehanna River Basin
led to the January 1996 basinwide flash flood?
An unusual combination
of heavy snowpack, high winds, unseasonably warm temperatures, heavy rainfall,
and ice jams resulted in the basinwide flash flood from January 19-21,
The heavy accumulation
of snow from the Blizzard of 1996 and previous snow events represented
about four inches of liquid equivalence. As the temperature and dew point
rose steadily during the night of January 18, the snowpack became saturated
and unable to absorb the additional precipitation from the heavy rainfalls
What were the
impacts and damages to the Susquehanna River Basin from the January 1996
- 14 lives were lost.
- More than $600
million in damages were suffered. The flood is considered the third
worst in the basin's history in terms of magnitude.
- The Chesapeake
Bay received the largest amounts of nutrients and sediments since the
1972 flood. The U.S. Geological Survey reported that the streamflow
during the flood were the highest January flows ever seen in the Susquehanna
- The Conowingo Dam
facility in Maryland recorded its second highest flow (909,000 cubic
feet per second) with a peak stage of 34.18 feet. According to the U.S.
Geological Survey, this was equivalent to having 27 large community
swimming pools being filled each second--about 6.8 million gallons per
- The formation or
breakup of ice jams caused rises in river levels as much as 8 feet in
- The U.S. Army Corps
of Engineers' reservoirs held back 167 billion gallons of flood waters.
This prevented more than $1.3 billion in additional damages.
- The peak flow at
Harrisburg, Pa., during the flood was 570,000 cubic feet per second--20
times the normal flow (normally 30,000 cubic feet per second for this
time of the year). The Susquehanna River rose from 7 feet to over 22
feet in little over 14 hours--the greatest surge occurred over a short
- The federal government
declared the entire Commonwealth of Pennsylvania as a disaster area.
Many New York counties, including all those in the basin, also were
declared disaster areas. Five counties in Maryland, including the basin's
Cecil County, were declared.
- Severe ice jams
destroyed about two-thirds of the skimmer wall at the Safe Harbor Water
Power Facility in Lancaster County, Pa. The Holtwood hydroelectric facility
also suffered significant damages. As a result, both facilities had
to push back the expected completion dates for their mechanical fish