Agnes began as a tropical disturbance off the coast of the
Yucatan Peninsula in Mexico on 14 June 1972. As the disturbance moved
northward, it strengthened and became a tropical storm on 16 June.
By 19 June, Agnes became a hurricane. Agnes made initial landfall
along the Florida pan handle on 19 June. Agnes then proceeded through
Georgia, South Carolina and North Carolina before she moved back over
the Atlantic off the North Carolina coast on 21 June,
After regaining strength over the Atlantic, she made
landfall again over southeastern New York on 22 June and moved
westward in an arc over southern New York into north-central
Pennsylvania. She became nearly stationary over Pennsylvania by
morning of 23 June, but was soon absorbed by a low-pressure
system that slowly drifted northeastward from Pennsylvania into
Rainfall from 20-25 June over the Mid-Atlantic region ranged
from 2-3 inches in the extreme upper basins of the Potomac and
North Branch Susquehanna Rivers to 18 inches near Shamokin, Pennsylvania,
in the Main Stem Susquehanna River basin. An average of 6-10 inches
of rain fell over the Mid-Atlantic region.
In the three weeks preceding the arrival of Agnes,
Pennsylvania as a whole had received 2 to 3 inches of rain, thus
greatly increasing the runoff potential of Agnes.
The most impressive aspect of the 1972 floods was their widespread
nature, resulting in extremely rare floods on major rivers and
streams. The flood recurrence frequency in many locations exceeded
100 years, most notably on the Susquehanna River downstream of
Waverly, New York, and on the Potomac River, downstream from Point of
Here's a look of the flooding, basin by basin:
Delaware River Basin
The worst flooding occurred in the Schuylkill River basin. Flood peaks in
excess of 100 year recurrence frequency levels were observed at many sites
along the Schuylkill. Major flooding also occurred on the tributaries of the
Schuylkill, primarily on the Tulpehocken, French and Perkiomen Creeks.
Elsewhere in southeastern Pennsylvania, significant flooding occurred on the
In the rest of the Delaware River basin, flooding was only minor.
A file containing stage data of the Delaware River basin can be found
Susquehanna River Basin
The Agnes flood remains the greatest flooding event known in the Susquehanna
River basin in regards to both the area affected and the magnitude of
the flood flow. Only the extreme upper headwaters escaped disastrous
Main Stem Susquehanna
Flooding along the Susquehanna above Binghamton, New York was only minor.
However, flood flows increased greatly downstream to Waverly, New York,
which had a 40 year flood. The points along the Susquehanna River from the
mouth of the Chemung River down to the Chesapeake Bay experienced the
worst flooding since 1784, the earliest known records. Peak flows were often
1.5 times greater than the previous know maximum flood.
Susquehanna River Tributaries
Some of the worst flooding occurred in the Chemung River and its
principal tributaries, the Tioga, Canisteo, and Cohocton Rivers.
Floods with greater than 100 year recurrence frequency level occurred at
almost every point in the basin. The peak flows were reduced somewhat
in the Canisteo River by the Arkport and Almond Reservoirs, but record
floods were still observed downstream of these dams.
Flooding on the West Branch of the Susquehanna River was reduced somewhat by
flood-control reservoirs, but the lower reaches of the West Branch
still experienced record high peak flows. It was estimated that the
flood peak at Williamsport, Pennsylvania, would have been up to 4 feet
higherif it had not been for the reservoirs. Major flooding was also
observed on all tributaries downstream of the West Branch Susquehanna
River down to the Juniata River.
The Juniata River basin experienced significant flooding, but it was
lessened by flood-control reservoirs, in particular, an
unfinished Raystown Lake reservoir.
A file containing stage data of the Susquehanna River basin can be found here.
Potomac River Basin
Above Hancock, Maryland, no unusual flooding was observed. Most of the
flooding occurred in tributaries of the Potomac River downstream of the
Shenandoah River. In the tributaries on the north side of the Potomac River,
from the Conococheague Creek at Fairview, Maryland down to Rock Creek at
Washington, DC, floods in excess of the 100 year frequency level were
observed. In the tributaries along the south side of the Potomac
River, severe flooding occurred at most locations in West
Virginia and Virginia from just west of Winchester, Virginia, and
artinsburg, West Virginia, to Alexandria and Quantico, Virginia.
Peak flows in some of the larger streams ranged from two to six times
greater than the previous known maximum.
A file containing stage data of the Potomac River basin can be found here.
Rappahannock River Basin
Flooding in the Rappahannock River basin was less severe in comparison
to the Potomac River to its north and the James River to its south.
any points in the basin had flooding with a 50 year recurrence
frequency and often were at the third highest levels on record.
A file containing stage data of the Rappahannock River basin can be found here.
James River Basin
The James River basin was also hit very hard by Agnes, especially
tragic since devastating floods caused by the remnants of Hurricane
Camille occurred only three years before. Flooding along the James
River downstream of Lynchburg, Virginia was the worst known since at
least 1870. Flooding along the main stem of the James River ranged
from 25 to 100 year recurrence frequency levels in the upper portions
to well over 100 year recurrence frequency levels downstream from
Lynchburg, Virginia. The flow at Richmond, Virginia, was 50% greater
than during the peak of the 1969 Camille flood.
In the headwater tributaries, severe flooding occurred along streams in
the vicinity of Covington, New Castle and Catawba, Virginia. Recurrence
frequencys in this area ranged from 50 to over 100 years. Flooding in
the tributaries between Buchanan, Virginia, and Scottsville, Virginia
were extensive, but not record breaking. In contrast, flooding in the
tributaries between Scottsville, Virginia, and Cartersville, Virginia,
were generally the greatest on record. The largest tributary in this
stretch, the Rivanna River, exceeded 100 year flood recurrence
frequency levels at many sites.
The Appomattox River, just to the south of the James, experienced
record breaking flooding upstream from Mattoax, Virginia. Sites above this
point experienced flooding greater than the 100 year recurrence
Below this point, flow contribution from the tributaries lessened,
resulting in the attenuation of the flood peak at it traveled down to
Farmville, Virginia, where it was only two-thirds of the flow that was
observed at Mattoax, Virginia.
A file containing stage data of the James River basin can be found here.
Hurricane Agnes was the costliest natural disaster in the United States at
that time. Damage was estimated at $3.1 billion and 117 deaths were reported.
Hardest hit was Pennsylvania, with $2.1 billion in damages and 48
deaths, making Hurricane Agnes the worst natural disaster ever to hit
the state. The damage over Pennsylvania was so extreme, the entire state was
declared a disaster area by President Richard Nixon.
The state-by-state breakdown is as follows:
||Damage (1972 Dollars)
Hurricane Agnes Rainfall and Floods, June-July 1972: United States
Geological Survey Professional Paper 924, Bailey, J.F.,
J.L. Patterson, USGS, and J.L.H. Paulhus, NWS. U.S.
Geological Survey: Washington, DC. 1975.
Water Resources Bulletin No. 9: Hydrologic Data of the June 1972
Flood in Pennsylvania Miller, R. Adam. Pennsylvania Department
of Environmental Resources: Harrisburg, PA. August 1974.
Tropical Storm Agnes June 1972: Post Flood Report Volume I,
eteorology and Hydrology Gannett, Flemming, Corddry and
Carpenter, Engineers. U.S. Army Corps of Engineers:
Baltimore, MD. November, 1974.