Flooding in Iowa, May 17 to 22, 1999

May 1999 will be remembered mainly for record flooding on the Wapsipinicon River, in addition to flooding at various other points on other area rivers. Moderate to heavy rains fell across east central Iowa from the 10th-13th causing the Wapsipinicon, Iowa, and Rock rivers to rise and subsequent minor flooding.On the 16th into the 17th two lines of thunderstorms developed#one north to south across western Iowa and moved west, and the other repeatedly developed east to west from Butler to Clayton counties in northeast Iowa and moved east. The training of thunderstorms in the northern line dropped extremely heavy rains across the Cedar, Wapsipinicon, and Mississippi river basins. Up to 8 inches (unofficially) of rain fell just north of Buchanan County in the Wapsipinicon basin. The Wapsipinicon River quickly rose above flood stage and brought record flooding to Independence and Anamosa. The crests recorded Independence and Anamosa were 22.32 feet (on the 18th) and 16.00 feet (on the 20th), respectively, the highest crests ever recorded there. The crest lessened slightly as it moved downstream, cresting near De Witt at 13.66 feet, the second highest crest on record there.The economic impacts to Independence were significant. Many houses and businesses from the north to south ends of town were flooded. Damage was mostly residential, with 50 to 75 residences impacted. Flooding downtown closed all three bridges over the river and required sandbagging of businesses along the bridges.Economic impacts to Anamosa were less significant than in Independence, but were still important. The bridge on the south end of town was closed due to high water and an estimated 10 residences on the southwest side of town were flooded. Sandbagging on the south end of Anamosa along the river helped save the south end of town from major flooding. Although no readings were available from the Maquoketa River at Manchester, moderate to major flooding occurred there also in response to heavy rains on the 16th and 17th. Mainly businesses downtown closest to the river were affected and some water made its way onto the road.Flash flooding occurred in Dubuque and East Dubuque in association with the heavy rains on the 16th and 17th. In East Dubuque the water washed away asphalt and concrete from roads in the downtown area. Damage also occurred to businesses due to high water. See flash flood reports for Dubuque and Jo Daviess Counties for the 16th and 17th of May for more details.Buchanan, Clinton, Delaware, Dubuque, Jones, and Linn Counties were declared Federal disaster areas due to the flooding.Moderate flooding also occurred on the Cedar and Mississippi rivers in response to the heavy rains and water from upstream. In the Quad Cities L/D 15, Illinois City L/D 16, Muscatine, New Boston L/D 17, Keithsburg, Oquawka, and Gladstone L/D 18 only minor impacts occurred. In Burlington and Keokuk, the industrial sections were protected by levees, and only minor impacts occurred with water encroaching into some parks and parking lots. The Mississippi River remained above flood stage at some points through the end of the month.