Increased arrivals of larger vessels, continued water conservation measures, fog and maintenance efforts is to blame for delays in transiting the canal of up to 11 days according to The Panama Canal Authority. The congestion began late September with the arrival of a large number of vessels coinciding with scheduled maintenance of the locks. Together with low visibility due to fog and low levels in the Gatun Lake due to drought from the El Niño weather pattern, the Panama Canal is facing one of the worst backlog of ships in recent times.