For months, excavators, backhoes and dump trucks have scraped up tons of dirt and sand along the Missouri River to pour into vast holes left by breaches in badly broken levees.

The scale of damage and the effort needed far exceeds the 2011 Missouri River flooding.

Months of frequent, heavy rains have made the repairs that much more difficult. Six months in, the Missouri River remains so high in some areas that crews haven’t been able to fully inspect damage to levees.

At least three times since March’s destructive flood, crews have scrambled — sometimes unsuccessfully — to protect fragile levee repairs from a rapid rise in the Missouri River.

Rains in May and August washed out some of the newly rebuilt levees. And now again in September, crews have been shoring up some of their yet-to-be completed work as more water surges downstream from heavy rain across northern Nebraska, South Dakota, Iowa and Minnesota.

“Our biggest obstacle is the river,” said Bret Budd, chief of the systems restoration team for the Army Corps of Engineers' Omaha District. “It’s high, and it remains high. Every time there’s a major rain — and we’ve had some — it increases the difficulty of the work.”