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.

Flood in SARPY, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: AVERY
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened during June and moderate flooding persisted into late August before releases from Gavins Point Dam began dropping.  Initially the high releases and flooding was due to snow melt and heavy rain, but persistent heavy rain events above Sioux City as the summer wore on kept the reservoirs full and releases high.  The river near Omaha climbed to around its 29 foot flood stage late in May and rose steadily through June reaching around 36 feet toward the end of the month. The river fell slightly during the first week of July but continued around 35 feet through much July before falling to around 34 feet over the first half of August.  By the end of August the river near Omaha had fallen to around 31 feet as decreased releases from Gavins Point allowed the river to fall into the minor flood category. However, minor flooding continued into September.  Flooding in Sarpy county spread into at least one park causing its closure. Boating and other recreational areas were also either flooded or closed. A section of the rail track that Amtrak used had to be closed to allow for its use as a levee during the height of the flooding.  The U.S. Army Corps of Engineers estimated that close to $1 million was spent on levee work/repair in Sarpy county during the flooding.

Flood in CASS, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: PLATTSMOUTH
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River in Cass county gradually worsened during June as record releases from Gavins Point Dam brought widespread flooding along the river. At Plattsmouth the Missouri River gradually rose through June reaching a little over 36 feet by the end of that month. Flood stage is 26 feet.  The river remained in major flood stage into early July then slowly dropped into the moderate category by mid July and continued in that category through mid August before dropping by the end of the month to around 30 feet.  However, minor flooding persisted through much of  September. The high water flooded farmland along the river along with a few roads and recreation areas, including a road to the Plattsmouth water treatment plant. Some businesses and homes were also flooded, and most of the 210 dwellings around Lake Waconda in the area were evacuated.

Flood in NEMAHA, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: PERU
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened over Nemaha county during June as record releases from Gavins Point Dam and periodic heavy rains brought widespread flooding along the River. The river at Brownville started June around 39 feet, flood stage is 33 feet. The river gradually climbed to a record crest around 45 feet by the end of that month before falling as downstream levees were breached and widened by flooding.   Moderate flooding persisted through July and into late August before the river fell even more due to decreased releases from upstream reservoirs.  However, minor flooding persisted into September.  Roads, including Highway 136 in Missouri, and the access road to a nuclear power plant, flooded as did recreation areas and farmland along the river. The flooding of Highway 136 prompted the closure of the Brownville, Nebraska bridge over the Missouri River. Over 8,000 acres were covered in flood waters during the peak of the flooding in early summer.

Flood in THURSTON, NEBRASKA
From 01-AUG-11 00:00:00 to 28-AUG-11 23:00:00 (CST-6)
Location: WINNEBAGO
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River continued across the area into August as record releases from Gavins Point Dam due to heavy rain above Sioux City brought  widespread flooding along the River.  Releases from Gavins Point Dam reached around 160,000 cfs after mid June and the high flows continued through July before decreasing some in early August and even more by the end of the month.  The gauge at Sioux City, upstream of the county, and Decatur, downstream, were in a moderate flooding category into early to mid August before falling sharply below flood stage late in the month.  Flooding in Thurston county was mostly confined to agricultural lowlands, recreation areas and roads near the river, but the flooding did force the evacuation of 12 people near Macy earlier in the summer.

Flood in BURT, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 21:00:00 (CST-6)
Location: DECATUR
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River continued into August as record releases from Gavins Point Dam, initially due to heavy rain and snow melt, and then to mostly heavy rain brought widespread flooding along the River. However, by the end of the month the river fell drastically as releases from Gavins Point Dam were cut way back and the river gauge at Decatur dropped below its 35 foot flood stage late on Aug. 31.  Earlier in the summer flooding in Burt county affected agricultural lowlands, recreation areas and roads near the river and also forced evacuation of 150 to 200 homes. Late in June the Highway 175 bridge over the Missouri between Decatur and Onawa was closed due to erosion of the abutment on the Iowa side of the bridge and the bridge remained closed during August.

Flood in DOUGLAS, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: EAST OMAHA
Flood cause: Heavy Rain
Property damage: 5.00M
Crop damage: 0.00K
Reported by: Official NWS Observations

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.

Flood in KNOX, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: VERDEL
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened over the area during June and July and persisted into August as record releases due to heavy rain and mountain snow melt above Ft. Randal Dam brought widespread flooding along the River.  In Knox county the flooding closed Highway 12 between Verdel and Niobrara and the highway east of Niobrara and also closed Highway 14/37 north of Niobrara.  The flooding also forced the evacuation of 50 to 60 residences including the Lazy River Acres area between Niobrara and Verdel.  The flooding carried over into September.

Flood in CEDAR, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: ATEN
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened over the area during June and July and continued into August before improving by the end of that month as record releases from Gavins Point Dam brought lowland flooding along the River.  In Cedar county the flooding generally began during the first week of the June as flows out of Gavins Point Dam reached and exceeded 100,000 cfs.  The flooding grew worse as the discharge reached 160,000 cfs by the end of June and these high releases continued into early August before moderating, especially by the end of the month.  A few seasonal or permanent homes were threatened by the flood waters, but in general the flooding was confined to low areas and farmland along the river.  The flooding continued into September.

Flood in RICHARDSON, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: BARADA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened during June as record releases from Gavins Point Dam brought widespread flooding along the River.  The river at Rulo rose to a record crest around 27 feet by the end of the June before falling slightly as levees were breached and widened by the flood waters.  Flood stage is 17 feet.  Although river levels steadily fell after mid August as upstream reservoirs reduced releases, moderate flooding persisted through August and into early September.  The high water flooded farmland along the river, along with roads, cabins, recreation areas and a few businesses.  Highway 159 in Holt county Missouri flooded by the middle of the June prompting the closure of the Rulo, Nebraska bridge over the Missouri River for the summer.

Flood in WASHINGTON, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: BLAIR ARPT
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened across Washington county during June and July and continued into August as record releases from Gavins Point Dam brought widespread flooding along the River. The high releases were initially due to heavy rain and snow melt but then to persistent heavy rain above Sioux City as the summer wore on.  The river near Blair reached a crest of a little over 32 feet during the last week or so of June, flood stage is 26.5 feet.  The river fell slightly during July but remained in the moderate category into late August and then fell steadily through the end of the month to a little under 28 feet by the 31st.  The flooding in Washington county was especially felt in the Fort Calhoun area where at least 60 homes or cabins were flooded or cutoff by flood waters. At least 200 residences in the county were evacuated leaving at least 500 people displaced. This prompted the city to open the high school up for flood victims. Blair spent $500,000 to build up a levee surrounding its water treatment plant.  The Ft. Calhoun Nuclear power plant was in refueling shut-down when the flooding started in April and because of the high waters remained shut-down through the summer as flood waters surrounded the plant prompting emergency sand bagging. In addition, recreation areas and roads along the river were flooded. The flooding persisted into mid September.

Flood in OTOE, NEBRASKA
From 01-AUG-11 00:00:00 to 31-AUG-11 23:59:00 (CST-6)
Location: NEBRASKA CITY ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flooding along the Missouri River gradually worsened during June and early July as record releases from Gavins Point Dam brought widespread flooding along the River. The river at Nebraska City, which climbed above its 18 foot flood stage in mid April, eventually reached a record crest of around 28 feet by the end of June before falling several feet in July as downstream levees were breached and widened. At least minor flooding continued through August and September although river values steadily dropped even more from late August into September as upstream releases were lowered substantially.  In Otoe county farmland, roads and recreation areas near the river flooded as did some cabins and a grain elevator near Nebraska City.  Flood waters crossed Highway 2 in Fremont county Iowa prompting its closure until late October.