These are the five worst floods in the United States in the 12 years since the federal flood insurance program took effect, according to the National Weather Service. All but one occurred before participation in the program became more widespread.
James River Basin, Va.-- In August, 1969, Hurricane Camille dropped 30 inches of rain on central Virginia in less than 8 hours, leaving 153 people dead and doing millions of dollars in property damage.
Buffalo Creek, W. Va.-- A dam of coal mine waste gave way after heavy rains in February, 1972, sending tons of water coursing down on the town, washing away hundreds of homes and killing 118 people.
Rapid City, S.D. -- A large, slow-moving thunderstorm unleashed torrents of rain on the Black Hills in June, 1972, generating floods that killed 236 people and did $100 million in property damage.
Northeastern United States -- The remnants of Hurricane Agnes drenched parts of Virginia, West Virginia, Maryland, Pennsylvania and New York in June, 1972; the floods killed 120 people and did $2 billion in property damage. (This storm prompted Congress to stipulate that no federally subsidized mortagage loans could be made in flood-prone communities that didn't participate.)
Big Thompson Canyon, Colo. -- In August, 1976, a thunderstorm dropped 12 inches of rain in the canyon in less than 3 hours, sending a 12-foot wall of water down the Big Thompson River. The flood drowned 139 campers and did millions of dollars' worth of property damage.