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Kansas Water Science Center

Water-Supply Paper 2502

Summary of Significant Floods in the United States, Puerto Rico, and the Virgin Islands, 1970 Through 1989

Summary of Significant Floods, 1970 Through 1989, by Year

This section includes brief descriptions of selected signficant interstate and intra-state floods in yearly accounts. Floods described in this section were those with excessive loss of life, excessive damage, extreme discharge or gage height, or those regional in extent. References are provided for these as well as other selected significant floods that occurred during the year. Figures 3-22 in this section depict widespread regional flooding by giving the percentage of streamflow-gaging stations in each State or territory recording greater than the approximate 20-year recurrence-interval flooding during the calendar year.


The first significant floods of 1980 occurred February 13 to 21 in southern California and Arizona (fig. 13). The floods were a result of six Pacific storms hitting the Southwest and creating an extended period of rainfall. This extended period of rainfall, not an excessive amount in one storm, caused the severe flooding. The resulting volumes of runoff in many streams south of Los Angeles, California, during February were the highest ever recorded. The 7-day volumes on the Salt and Verde Rivers in Arizona were the second and third highest, respectively, recorded since 1906 (Chin and others, 1991). These excessive volumes caused all the reservoirs in southern California, except Lake Henshaw in San Diego County, to have spillway releases. Seven reservoirs in Arizona on the Salt, Verde, and Agua Fria Rivers had spillway releases. The floods caused 18 deaths and $350 million in damages (Paulson and others, 1991).

Intense rains hit Louisiana, Mississippi, and Alabama in two consecutive storms in March and April. The first storm occurred from March 26 to April 2 and struck southeastern Louisiana and scattered areas in Mississippi. The second storm lasted from April 11 to April 13 and affected most of Mississippi and was especially intense in the area from Baton Rouge and New Orleans, Louisiana, to Mobile, Alabama. The 2-hour rainfall in Mobile on April 13 had a recurrence interval of 100 years. As a result of this rainfall, Mobile experienced the worst flash floods in the city's history.

The most devastating hydrologic event during the year occurred on May 18 with the eruption of Mount St. Helens in Washington. The eruption caused very rapid melting of the mountain's snow and ice, creating severe mudflows along the North Fork Toutle, South Fork Toutle, and lower Cowlitz Rivers and throughout the Lewis River Basin in Washington. The mudflows had substantial effects on the streams and flood plains as large quantities of sediment were deposited. The mudflows deposited about 11,000 acre-ft of water, mud, and debris in Swift Reservoir on the Lewis River. The sediment that was deposited from these mudflows caused changes in the characteristics of flow in many of the streams in the area and required flood profiles to be reworked in the affected areas.

The month of August brought almost continuous rain to West Virginia, southwestern Pennsylvania, and eastern Ohio. Many precipitation stations reported rain during almost every day from August 2 to 22, and daily totals of 2 in. or more were very common. On August 9, thunderstorms produced 3.0 to 3.5 in. of rain in 1 hour over Clarksburg, West Virginia (National Oceanic and Atmospheric Administration, 1980). Flooding was particularly severe in the town of Lost Creek, West Virginia.

Hurricanes and tropical storms ravaged the coastal areas of Texas in August and September. Hurricane Allen, the first of the season, was the most intense ever recorded in both the eastern and western parts of the Caribbean Sea. The storm made landfall on August 9 in Texas, and tidal surges 10 to 20 ft above sea level were recorded along the southern coast. The tidal flooding was the worst since 1919. Tropical Storm Danielle, which made landfall in eastern Texas on September 5, did not produce the high winds and tidal flooding that Hurricane Allen did, but the storm did produce torrential rains. Urban flooding caused by the excessive rainfall was the most destructive element of this storm. Tropical Storm Jeanne in mid-November also caused coastal flooding along the entire coast of Texas with the worst flooding near Galveston.

Selected References for 1980

Aldridge, B.N., 1982, Hydrology of the floods of March 1978 through February 1980 in the Phoenix area, Arizona, in Storms, floods, and debris flows in southern California and Arizona 1978 and 1980, Proceedings of Symposium, September 17-18, 1980, California Institute of Technology: Washington, D.C., National Academy Press, 16 p.

California Institute of Technology, 1982, Storms, floods, and debris flows in southern California and Arizona 1978 and 1980, Proceedings of Symposium, September 17-18, 1980, California Institute of Technology: Washington, D.C., National Academy Press, 487 p.

Chin, E.H., Aldridge, B.N., and Longfield, R.J., 1991, Floods of February 1980 in southern California and central Arizona: U.S. Geological Survey Professional Paper 1494, 126 p.

Cummans John, 1981, Mudflows resulting from May 18, 1980, eruption of Mount St. Helens, Washington: U.S. Geological Survey Circular 850-B, 16 p.

Gallino, G.L., and Pierson, T.C., 1984, The 1980 Polallie Creek debris flow and subsequent dam-break flood, East Fork Hood River Basin, Oregon: U.S. Geological Survey Open-File Report 84-578, 37 p.

Gilbert, J.J., and Froehlich, D.C., 1987, Simulation of the effect of U.S. Highway 90 on Pearl River floods of April 1980 and April 1983 near Slidell, Louisiana: U.S. Geological Survey Water-Resources Investigations Report 85-4286, 47 p.

Haeni, F.P., 1983, Sediment deposition in Columbia and lower Cowlitz Rivers, Washington-Oregon, caused by May 18, 1980, eruption of Mount St. Helens: U.S. Geological Survey Circular 850-K, 21 p.

Hannum, C.H., and Nelson, G.H., 1980, Flood of April 13, 1980, Mobile, Alabama: U.S. Geological Survey Open-File Report 80-1183, 6 sheets.

Hershfield, D.W., 1961, Rainfall frequency atlas of the United States: U.S. Department of Commerce, Weather Bureau Technical Paper 40, 115 p.

Jennings, M.E., Schneider, V.R., and Smith, P.E., 1981, Emergency assessment of Mount St. Helens post-eruption flood hazards, Toutle and Cowlitz Rivers, Washington: U.S. Geological Survey Circular 850-I, 17 p.

Kolva, J.R., and Koltrun, G.F., 1987, Flooding and sedimentation in Wheeling Creek Basin, Belmont County, Ohio: U.S. Geological Survey Water-Resources Investigations Report 87-4053, 33 p.

Kuehnast, E.L., Baker, D.G., and Zondlo, J.A., 1988, Sixteen-year study of Minnesota flash floods: Minnesota Department of Natural Resources, Division of Waters, State Climatology Office and University of Minnesota, Soil Science Department, 72 p.

Lee, F.N., and Arcement, G.J., Jr., 1981, Hydrologic analysis of Pearl River floods, April 1979 and April 1980 in Louisiana and Mississippi: Louisiana Department of Transportation and Development, Office of Highways Research Study No. 81-1-SS, 37 p.

Lee, J.K., Froehlich, D.C., Gilbert, J.J., and Wiche, G.J., 1983, A two-dimensional finite-element model study of backwater and flow distribution at the I-10 crossing of the Pearl River near Slidell, Louisiana: U.S. Geological Survey Open-File Report 82-4119, 60 p.

Lipman, P.W., and Mullineaux, D.R., eds., 1981, The 1980 eruptions of Mount St. Helens, Washington: U.S. Geological Survey Professional Paper 1250, 844 p.

Lombard, R.E., 1986, Channel geometry, flood elevations, and flood maps, lower Toutle and Cowlitz Rivers, Washington, June 1980 to May 1981: U.S. Geological Survey, Water-Resources Investigations Report 85-4080, 34 p.

Lombard, R.E., Miles, M.B., Nelson, L.M., Kresch, D.L., and Carpenter, P.J., 1981, Channel conditions in the lower Toutle and Cowlitz Rivers resulting from mudflows of May 18, 1980: U.S. Geological Survey Circular 850-C, 16 p.

Mann, L.J., and Rohne, P.B., Jr., 1983, Streamflow losses and changes in ground-water levels along the Salt and Gila Rivers near Phoenix, Arizona-February 1978 to June 1980: U.S. Geological Survey Water-Resources Investigations Report 83-4043, 11 p.

National Oceanic and Atmospheric Administration (NOAA), 1980, Climatological data (by State): Ashville, North Carolina, National Climatic Data Center, (various months).

____1981, The disastrous southern California and central Arizona floods, flash floods, and mudslides of February 1980: National Weather Service, Natural Disaster Survey Report NWS-81-1, 134 p.

Paulson, R.W., Chase, E.B., Roberts, R.S., and Moody, D.W., compilers, 1991, National water summary, 1988-89-Hydrologic events and floods and droughts: U.S. Geological Survey Water-Supply Paper 2375, 591 p.

U.S. Army Corps of Engineers, 1981a, Pearl River basin reconnaissance report-stage 1 report: Mobile District, Alabama, 200 p.

____1981b, Report on Hurricane Allen, 3-10 August, 1980: Galveston District, Texas, 62 p.

Wahl, K.L., Crippen, J.R., and Knott, J.M., 1980, Floods of January and February 1980 in California: U.S. Geological Survey Open-File Report 80-1005, 52 p.

Wesson, R.L., 1981, The eruption of Mount St. Helens-entering the era of real-time geology: U.S. Geological Survey Yearbook, 1980, p. 7-15.

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