Flood — Delaware, Iowa

2010-07-23 to 2010-07-25 · near Backbone State Park, Delaware, Iowa

Event narrative

After about 10 inches of rain fell in the upper Maquoketa River basin, the river surged to record stage levels.

The initial impact off the surging river levels was seen in Manchester, where portions of the business district as well as numerous homes were affected by flood waters. With water reaching near the rooftops of at least one business, West Main Street was particularly hard-hit, with 2 fast food restaurants, a car dealership, a pharmacy, and several other businesses succombing to the flood waters. Numerous basements filled with water, and there were reports of several basement walls that had collapsed. One man experienced a near-miss when a sinkhole developed in a parking lot and the skidloader he was driving collapsed into the raging Maquoketa River beneath the parking lot.

County conservationists estimated that about 2000 acres of crops and another 2000 acres of pasture were covered by the flooded Maquoketa River, their yields almost entirely lost.

Numerous properties were damaged along the river, including about 500 homes bordering Lake Delhi. Four to five feet of water filled some homes and businesses, including the Lake Delhi marina office.

On Saturday July 24th the Lake Delhi dam failed, allowing the water to drain rapidly from the lake and flood waters to recede from the Lake Delhi properties. Please see the Storm Data entry for the Delaware County flash flood on 7/24 for a description of the Lake Delhi dam failure and its direct impacts.

Wider weather episode

Heavy rains during the fourth week of July resulted in the Maquoketa River at Manchester going above the moderate flood stage level of 17 feet on July 23 around 1130 am CDT. It surged past its previous record of 21.66 ft in 2004, cresting around an unprecendented stage of 24.5 feet (preliminary) around 7 pm CDT July 24. It fell below the moderate flood stage level around 1015 am CDT July 25.

View location on OpenStreetMap → (42.6000, -91.7000)

Source: NOAA Storm Events Database, event_id 251376. Narrative written by the NWS forecast office that issued the report.