Flood — Douglas, Nebraska

2011-08-01 to 2011-08-31 · near East Omaha, Douglas, Nebraska

Event narrative

Flooding along the Missouri River in Douglas county gradually worsened during June and moderate flooding persisted into August as record releases from Gavins Point Dam brought widespread flooding along the River. Initially the high releases were due to heavy rain and snow melt, but as the summer wore on persistent heavy rain events above Sioux City and some lingering snow melt in the higher elevations of the rockies kept the reservoir system full and with high releases. At Omaha the river climbed to around its 29 foot flood stage late in May and rose steadily through June reaching around 35 feet late in the month, briefly crossed 36 feet in early July before settling back to around 34 feet in early to mid August. By the end of August decreasing outflows from Gavins Point Dam had allowed the river near Omaha to drop to around 31 feet. The flooding in Douglas county along the Missouri River closed several parks, boating accesses, and recreational areas. Low areas around downtown on the river side of the federal levee were flooded. The high water and persistent pressure on levees forced Eppley airfield and other businesses to constantly monitor the situation and have pumps on standby as either rains, storm sewer backups or minor boils near the levee would force pumping of the water back over the levee. The U.S. Army Corps of Engineers estimated to have spent a little over $2 million on levee repair/work in Omaha alone for the event. By the end of August the city of Omaha's tab for the flood fight had totaled $10 million. Minor flooding persisted into mid September.

Wider weather episode

A record rain event in May in eastern Montana combined with high water from storms in April and May, plus snow melt from a much above normal snow pack, all contributed to bring record high water to the Missouri River chain of reservoirs by late Spring. Then residual snow melt and additional rains produced record 13.8 million and 10.0 million acre feet of runoff above Sioux City in June and July respectively. This helped contribute and sustain record releases from the Missouri River Reservoirs from mid June into early August. Releases from Gavins Point Dam, which is the last in the chain, reached around 160,000 cfs by the middle of June and remained that high into early August before dropping to around 90,000 cfs by the end of the month which help alleviate some of the flooding. The flooding continued into September but moderated greatly. However, OPPD reported that costs associated with the flooding totaled $44.5 million as of August 11th, $28.7 million for flood-protection and $15.8 million for power replacement due to the continued shutdown of the Ft. Calhoun Nuclear Station. Local Governments and Eppley's Airport Authority spent around $42 million monitoring levees, pumping out groundwater and re-plumbing the drainage system. By the end of September the Omaha district of the U.S. Army Corps of Engineers estimated it spent $56 million directly and indirectly in battling the river throughout its share of the basin.

View location on OpenStreetMap → (41.3975, -95.9759)

Source: NOAA Storm Events Database, event_id 322970. Narrative written by the NWS forecast office that issued the report.