U.S. Floods of 1982

By C.A. Perry, B.N. Aldridge, and H.C. Ross of the USGS

The San Francisco Bay area of California experienced the first significant flooding of 1982 when an intense storm system came onshore during January 3 through 5. The storm caused continuous, moderate rainfall for about 34 hours over the San Francisco Bay area. Landslides began around 9:00 a.m. on January 4 and quickly transformed to debris flows. In addition to the landslides and debris flows, flooding was considerable throughout the area. Many small streams had maximums of record, but the record lengths for streams in the area are relatively short. There were 31 deaths, and total damage from the storm was $75 million.

A rapid increase in temperatures caused spring snowmelt floods in Indiana, Michigan, and Ohio in March. In addition to the melting of a deep snowpack, moderate rains fell across the area, which intensified the melting. Continued periods of rain throughout the month resulted in streams sustaining high flow and causing additional maximum discharges. Recurrence intervals for maximum discharges recorded at several streamflow-gaging stations in the St. Joseph, Yellow, Maumee, and Kankakee River Basins were 50 to 100 years.

On March 31, a cold front collided with warm Pacific air over central California causing 2 in. of rain to fall in San Jose during a very short period of time. Six streams in and near San Jose overflowed and forced the evacuation of 50 homes. Some of the floodwaters were stored in the Coyote and Anderson Reservoirs upstream from San Jose, which helped reduce the severity of the flooding.

Excessive rainfall fell mostly during the last 3 weeks of May and first week of June over much of western South Dakota. Spearfish received 11.22 in. of rain from May 14 to 21 and had a total of 14.31 in. for the month of May. Other rainfall amounts for May were 11.30 in. at Elm Springs, 10.70 in. at Lead and at Belle Fourche, 9.90 in. at Eagle Butte, 9.87 in. at Milesville, 9.85 in. at Wasta, and 9.53 in. at Timber Lake. Near-record stages were recorded on the Little Missouri, Moreau, Belle Fourche, Cheyenne, and White Rivers.

A storm that local newspapers dubbed "the worst spring storm during the 20th century" ravaged through Connecticut, eastern New York, and central and eastern Massachusetts on June 5 through 7. The storm produced rainfall totals as high as 16 in. in Connecticut (National Oceanic and Atmospheric Administration, 1982). At several places, the rainfall recorded with the storm was the highest recorded for a non-hurricane storm. This storm resembled a "northeaster" without the cold temperatures. Almost every stream in Connecticut flooded, with central Connecticut being the hardest hit. Eleven deaths and damages of $250 million were caused by the floods (Paulson and others, 1991).

Persistent moderate to intense rains throughout May resulted in record flooding in Iowa in June and July. The floods occurred mostly in southwestern and east-central Iowa. Many streams had record discharges. The maximum discharges for Old Mans Creek at Highway 149 near Williamsburg were twice the 100-year recurrence-interval flood. One of the largest floods ever recorded in Iowa occurred July 3 on Cedar Creek near Bussey. The recorded discharge was more than twice that of a 100-year recurrence-interval flood.

Early in the morning of July 15, an earthen dam in the Front Range of the Colorado Rocky Mountains failed, releasing 674 acre-ft of water and an estimated maximum discharge of 18,000 ft³/s down Roaring River Valley. The onslaught of water caused another dam downstream to fail also. Geomorphic and sedimentologic evidence suggest that this was probably the largest flood in the Roaring and Fall River Basins since the retreat of the glaciers about 10,000 years ago. Along the course of the flood, channels were widened tens of feet and either scoured or filled. An alluvial fan of 42.3 acres, containing about 226 acre-ft of material, was deposited at the month of the Roaring River. The alluvial fan dammed the Fall River, forming a lake of 17 acres upstream from the fan. Three people were killed, and total damages from the flood were estimated at $31 million (Paulson and others, 1991).

Intense thunderstorms produced by a nearly stationary weather front over Kansas City, Missouri, caused significant flooding August 12 through 13. Flash flooding was prevalent during the night and early morning hours on August 12. These floods affected much of the same area as the 1977 floods in Kansas City. Maximum discharges at several stations exceeded the discharges recorded for the 1977 flood. Four deaths occurred from the flooding, and damages were estimated at about $30 million.

Flood-producing thunderstorms moved through Tennessee on four separate occasions from July to September. On July 31, 2.5 to 6 in. of rain caused flash floods in eastern Tennessee. Record-breaking floods in central and eastern Tennessee on August 17 resulted from rainfall that exceeded the 100-year expected rainfall. Flooding continued on August 30 through September 4 in north-central Tennessee. Water covered major highways, washed out bridges, and prompted evacuations of approximately 300 people.

Remnants of Tropical Storm Chris caused torrential rains and flooding throughout Louisiana, Mississippi, Tennessee, and Kentucky on September 12. Significant flooding occurred along the Rutherford and South Forks of the Obion River and the North and Middle Forks of the Deer River in western Tennessee.

On November 23, Hurricane Iwa passed 30 mi west of Kauai and became the most costly storm to hit the State of Hawaii. The Federal Emergency Management Agency (FEMA) estimated losses at $308 million. Most of the damage was a result of high tidal surges as the winds were very high, but little rain fell. Surge levels exceeded the 100-year flood, and the debris line left by the tidal surge on Kauai was as much as 900 feet inland from the boundary of the 100-year flood level shown on FEMA flood-insurance maps.

Widespread flooding occurred in December 1982 and January 1983 in the Mississippi River Basin. Streams in Illinois, Missouri, Arkansas, Louisiana, Mississippi, and Tennessee were hardest hit by the floods. Flooding resulted from two main periods of intense rains; the first storm occurred from December 2 through 7 and the second from December 24 through 29. Missouri, Illinois, and Arkansas were affected by the earlier storm, and Louisiana and Mississippi were affected by the later storm. Significant floods, many of which exceeded the 100-year recurrence intervals, occurred in Missouri in the Gasconade, Osage, Meramec, St. Francis, and Current River Basins. In Arkansas, the Buffalo River experienced record flooding. Louisiana experienced extensive flooding as well, with most of the damage occurring along the Calcasieu, Little, Black, Red, and Ouachita Rivers.

Source: USGS.