DES MOINES, Iowa (AP) – A National Weather Service hydrologist says the Big Sioux River peaked earlier and lower than expected at Sioux City because significant water was released when a levee failed upstream. National Weather Service Hydrologist Mike Gillispie says the Tuesday night levee failure 27 miles upstream at Akron, Iowa, allowed water to spill onto agricultural land, dropping the river level downstream.

The river had been expected to crest Friday at Sioux City about a foot above the 108.3-foot record set in 1969. Instead it peaked at about 105 feet overnight and began dropping.Gillispie says the river at Sioux City will stay elevated longer than previously predicted.

He expects the river to fall below the 99-foot flood stage, the level at which farmland around Sioux City is underwater, by Monday morning.