(MCT) — WASHINGTON — Lawmakers from drought-stricken states along the Mississippi River on Thursday asked the U.S. Army Corps of Engineers and President Barack Obama to act quickly to remove navigation hazards from the river that threaten to slow or stop barge traffic.

Low water levels have made it difficult for the corps to maintain a 9-foot-deep and 300-foot-wide navigation channel for barges along the river, an economic lifeline that carries billions of dollars of agricultural products, coal, chemicals and petroleum.