U.S. Floods of 1979
By C.A. Perry, B.N. Aldridge, and H.C. Ross of the USGS
On February 20, 1979, a record-breaking storm hit the Island of Hawaii
and inundated the island with torrential rains for the following 72 hours.
Twenty-three inches of rains fell at the Hilo Airport in 24 hours. This
surpasses the previous record rainfall in 24 hours by more than 5 in.
Record 48- and 72-hour rainfalls also were recorded. The resulting floods
ranged in magnitude from discharges having recurrence intervals of 10 to
100 years. Runoff from the rains caused roads to be closed for several
hours, caused flooded basements, and eventually ponded in low-lying areas.
Streams in and around Hilo had near-record flows.
Spring flooding was severe in parts of Illinois and Missouri. Nearly
every stream in Illinois was above flood stage during March. Flooding was
especially severe along the Rock and Kankakee Rivers. The high tributary
inflow caused the Mississippi River to be 7 to 12 ft above flood stage,
but the river was easily contained within the levees except in areas where
major rivers, such as the Illinois and Missouri, flow into the
The worst flooding since 1969 struck Minnesota late in March. Rapid
snowmelt caused flooding in the Red River of the North Basin.
Several floods occurred in the southeastern United States from March to
May. The worst of these floods was caused by the rainfall on March 3-4 and
April 11-14. On March 3-4, 10 to 14 in. of rain fell near Pensacola,
Florida, as much as 12 in. fell in eastern Mississippi, and 8 in. fell in
western Alabama. Maximum discharges of record and discharges with
recurrence intervals of 100 years occurred in parts of the Tallapoosa
River Basin of Georgia and Alabama. Rains on April 11-13 caused severe
flooding in Mississippi, Alabama, and the northwest corner of Georgia.
Floods reaching 50- to 100-year recurrence intervals were recorded in the
downstream reaches of the Coosa and Tallapoosa Rivers in Alabama. Several
tributaries in the middle of the Tombigbee River Basin and the lower half
of the Black Warrior River Basin, both in Alabama, had the highest
discharges in 80 to 100 years. On most streams in the northern and eastern
part of the Pearl River Basin in Mississippi discharges were greater than
the 100-year recurrence interval. Damages from these floods in
Mississippi, Alabama, and Georgia totalled $386 million. Floods also hit
the Austin-San Antonio and Houston-Galveston areas of Texas in April.
These were the worst floods, in terms of water levels, number of people
affected, and dollar damages, to occur in the Houston area.
Tropical Storm Claudette caused severe flooding from Texas to Indiana
after it made landfall in Louisiana on July 24. The storm caused
torrential rains in 12 counties in the extreme southern corner of eastern
Texas that includes the Houston and Galveston areas. Rainfall was 20 to 40
in. over the area. Floods occurred on many small creeks and bayous between
and within the San Bernard and Trinity River Basins. Southern Indiana was
also hit by remnants of Tropical Storm Claudette, which produced as much
as 10 in. of rain in some areas. Severe floods resulted, especially in
Three hurricanes affected the United States during late August and
early September. Hurricanes David, Elena, and Frederic hit the
Southeastern States, and David and Frederic also hit Puerto Rico. None of
the hurricanes caused significant flooding in the continental United
States. However, intense thunderstorms associated with the hurricanes
caused flash flooding and coastal storm surges. Puerto Rico had
significant floods on some of its rivers due to Hurricane David. Floods on
some of the eastern and southeastern streams in Puerto Rico were
classified as 25-year floods.
Floods hit Texas and Louisiana again on September 17-25. The streams
and rivers in the area were already swollen from the July floods and the
rain from the hurricanes when 48 to 60 hours of continuous rain fell on
coastal counties of eastern Texas and southwestern Louisiana.