OMAHA -- Boating on the Missouri River in the Sioux City area resumed Tuesday, but vessels must obey speed limits due to continued high water levels.
The U.S. Coast Guard last week closed the river to all recreational and commercial boats, from mile marker 330, near St. Louis, to river mile marker 750, about 18 miles north of Sioux City, because of existing hazards such as drifting and high water. Officials also feared vessel traffic might cause damage to or overtopping of flood control levees.
The river is now open to traffic from Napoleon, Missouri, just east of Kansas City, to just north of Sioux City.
Runoff due to above-average rainfall this spring in the Midwest, coupled with high releases from Gavins Point Dam near Yankton, South Dakota, has pushed the Missouri River out of its banks in several locations in Iowa, Nebraska, Kansas and Missouri. Flooding in the Sioux City area has been minor, but heavier flooding has occurred to the south, forcing the closure of Interstate 29 north and south of Council Bluffs and Interstate 680 east from Omaha to Iowa.
Though the river has reopened to traffic, the Coast Guard has imposed slow, "no wake" zones around South Sioux City and Plattsmouth, Nebraska due to the river remaining at moderate or major flood levels.
"For the safety of the boaters and to prevent impacts to local infrastructure, boating in these conditions in not recommended," the Coast Guard said in a bulletin. "Many counties, towns and communities are actively conducting flood fighting activities and recreational boating in areas of active flood fights can adversely impact these efforts."
Gavins Point releases have been at more than twice the normal level for weeks as the U.S. Army Corps of Engineers continues to evacuate near-record amounts of runoff from heavy rainfall into the river's six reservoirs. Releases have held steady at 75,000 cubic feet per second. The normal level is 30,000 cfs.
Widespread and heavy rainfall in Nebraska and South Dakota led to the second-highest runoff in the upper Missouri River basin above Sioux City in 121 years of record keeping. May runoff was 8.9 million acre-feet, second only to 9.2 MAF in 2011. Average May runoff is 3.3 MAF.
The corps has forecast 2019 runoff in the river's upper basin at 50 MAF, which would be second only to 61 MAF in 2011.