TULSA, Okla. (AP) — U.S. Sen. Jim Inhofe says an Arkansas River system that runs from Tulsa to the Mississippi River is facing a $225 million backlog of “critical” upkeep projects after being hindered for months this summer by historic flooding in Oklahoma.

The Tulsa World reports the Environmental and Public Works Committee’s senior member submitted a statement Wednesday for a committee hearing to discuss the next Water Resources and Development Act legislation.

The McClellan-Kerr Arkansas River Navigation System is 445 miles (716 kilometers) long.

Inhofe says the system supports financial activity across a 12-state region, moving 10.9 million tons (9.89 million metric tons) of commerce worth $3.5 billion yearly. But he noted Tulsa’s port has been closed to barge traffic since May.

Inhofe says silt needs to be removed from the channel and re-dredging likely won’t be finished until November.