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.

1970

Excessive rain falling on snow during January and February was responsible for flows in the Sacramento River in California that were the highest since construction of Shasta Dam (fig. 3). The death toll was 18, and there was $38 million in damages (Paulson and others, 1991). There were also record maximum discharges in the lake basins of northeastern California. Additional flooding extended from northeastern California to northeastern Oregon.

Extensive flooding occurred in early March from northeastern Louisiana across north-central Mississippi and again later in the month from Mississippi across Alabama and into southern Georgia. Highest recurrence-interval floods (50 year) occurred on streams in southwestern Georgia.

The Red River of the North in North Dakota and Minnesota was above flood stage from April 10 to May 10 as a result of melting of a deep winter snowpack and recurring precipitation. Record stages also occurred on the Des Lacs River at Foxholm (station 05116500, table 35), in northwestern North Dakota. Excessive rain and flooding from May 8 to 14 resulted in 21 counties in North Dakota and 11 counties in Minnesota being designated as disaster areas. A greater than 50-year recurrence-interval flood on the Deep River at Deep River, Iowa (station 05455230, table 16), occurred on May 14. Flash floods in extreme northwest Iowa on May 28 caused extensive damage.

During September 4-6, the "Four Corners" area of Arizona, Colorado, New Mexico, and Utah was subjected to monsoon-type thunderstorms that created flash floods over a large area. There were 23 deaths and $10 million in damages (Roeske and others, 1978).

During October 5-10, the eastern two-thirds of Puerto Rico was subjected to excessive rainfall from a stalled tropical storm. As much as 38.4 in. of rain fell in Puerto Rico over a 6-day span (Environmental Sciences Services Administration, 1970). Eighteen persons lost their lives as a result of flooding, and damages were estimated at $68 million (Paulson and others, 1991).

Selected References for 1970