(MCT) — Even in the best of times, the Mississippi River is a slow and torpid thoroughfare. But when an extended drought persists and the muddy waters recede, squeezing barges through the narrow channels becomes an expensive, and sometimes impossible, chore.

The great summer drought of 2012 has closed lower sections of the river, shut down harbors and forced barges to run aground as river levels drop to near-record lows. With no significant rains in sight, authorities responsible for keeping the Mississippi open for commerce say things are likely to get worse before they get better.