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 flood of 1971 occurred in February across Nebraska, Iowa, Illinois, and Wisconsin (fig. 4). Significant flooding occurred on streams in eastern Nebraska, and some discharges were considered maximum-of-record floods. Ice jams caused flooding on the Rock River in northwestern Illinois on February 24.

Spring rains caused extended flooding in the Southeastern States during March. Record floods occurred in Georgia on the Ocmulgee River. Many streams were above flood stage throughout March.

Snowmelt caused flooding in Utah, Idaho, and Wyoming during May and June. Significant flooding occurred in the Green River Basin in Wyoming. The discharge on the Bear River near Smithfield, Utah (station 10102250, table 46), was considered a 75-year recurrence-interval flood.

Discharges having recurrence intervals of 25 to 100 years were recorded on the North Platte River in Nebraska. The floods occurred in early June as a result of mountain snowmelt upstream in Wyoming. Excessive rainfall in the basin added to the intensity of the floods.

Significant flooding occurred in southern Pennsylvania, eastern Ohio, and northern West Virginia during June and July. One of the most damaging thunderstorms in the last 50 years struck the Baltimore, Maryland, area on August 1. Streamflow-gaging stations in the area recorded discharges with recurrence intervals of 100 years. Fourteen deaths and $6.5 million in damages resulted from the floods (Paulson and others, 1991).

Tropical Storm Doria moved along the eastern seaboard from North Carolina to Maine late in August. The resultant storm system caused rain over North Carolina for the next 2 weeks. The rains eventually spread over the entire East Coast reaching into Maine. Record floods occurred on several small streams in New Jersey and southeastern Pennsylvania.

Extended flooding occurred from September until October in Texas, Louisiana, and Oklahoma. Several storms caused flooding in Oklahoma in early September. Hurricanes Edith and Fern caused floods in Louisiana in September and October. Rivers stayed above flood stage into November.

Significant flooding occurred in western Arkansas and extreme southeastern Oklahoma on December 9-10. Damages totalled as much as $16 million (Paulson and others, 1991). The discharge on the Trinity River near Crandall, Texas, was the second highest since 1949.

Selected References for 1971

Aldridge, B.N., 1972, Investigation of floods from small drainage basins in Arizona, in Proceedings of the 21st annual conference on roads and streets: Tucson University of Arizona, Arizona Transportation and Traffic Institute, p. 107-126.

____1978, Unusual hydraulic phenomena of flash floods in Arizona: American Meteorological Society, Hydrometeorological Aspects, p. 117-120.

Carmody, Thomas, 1980, A critical examination of the largest floods in Arizona-a study to advance the methodology of assessing the vulnerability of bridges to floods for the Arizona Department of Transportation: The Engineering Experiment Station, College of Engineering, 52 p.

Carpenter, D.H., 1974, Floods of August and September 1971 in Maryland and Delaware: U.S. Geological Survey Open-File Report 74-1015, 35 p.

Eychaner, J.H., 1984, Estimation of magnitude and frequency of floods in Pima County, Arizona, with comparisons of alternative methods: U.S. Geological Survey Water-Resources Investigations Report 84-4142, 69 p.

Gilstrap, R.C., 1973, Floods of December 1971 in western Arkansas: Arkansas Geological Commission Report Number 8, 26 p.

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

House, P.K., and Pearthree, P.R., 1994, A geomorphic and hydraulic evaluation of an extraordinary flood discharge estimate-Bronco Creek, Arizona: Arizona Geological Survey Open-File Report 94-19, 21 p.

Kuehnest, E.L., Baker, D.G., and Zandlo, 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.

Lamke, R.D., 1972, Floods of the summer of 1971 in south-central Alaska: U.S. Geological Survey Open-File Report 72-215, 88 p.

National Oceanic and Atmospheric Administration (NOAA), 1971, Climatological data (by State); Ashville, N.C., National Climatic Data Center, (various months).

---1972, North Atlantic tropical cyclones: National Weather Service, Climatological Data, p. 746-748.

Page, L.V., and Shaw, L.C., 1973, Flood of September 1971 in southeastern Pennsylvania: U.S. Geological Survey Open-File Report 73-217, 33 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.

Stankowski, S.J., 1972, Floods of August and September 1971 in New Jersey: New Jersey Department of Environmental Protection, Division of Water Resources Special Report 37, 350 p.

Tate, C.H., 1973, Floods of the 1970 and 1971 water years in Mississippi: Mississippi State Board of Water Commissioners Bulletin 73-2, 20 p.

Thomas, W.D., Jr., and Corley, R.K., 1973, Floods of 1971 and 1972 in Glover Creek and Little River in southeastern Oklahoma: U.S. Geological Survey Water-Resources Investigations 5-73, 2 sheets.

U.S. Army Corps of Engineers, 1971a, Post flood report, floods of January 27-28, 1971, Islands of Oahu, Maui, and Hawaii: Pacific Ocean Division, State of Hawaii, Department of Land and Natural Resources C31, 28 p.

____1971b, Report of the flood of March 1971, Lumber River, North Carolina: Charleston District, South Carolina, 9 p.

____1971c, After action report, spring floods, upper Mississippi River: Rock Island District, Illinois, 29 p.

____1971d, Hurricane Fern, September 13, 1971, post flood report: Galveston District, Texas, 21 p.

____1972a, After action report, operation foresight, 1971 spring floods: St. Paul District, Minnesota, 26 p.

____1972b, Office report, May-June 1971 snowmelt floods, Bear River Basin, Idaho, Utah, Wyoming, and Green River Basin, Wyoming: Sacramento District, California, 23 p.

____1975, The flood of August and September 1971 (Hurricane Doria): New York District, 225 p.

____1977, Flood plain information study for Rock River, Illinois: Rock Island District, Illinois, 52 p.

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