Mainly, the ACP started reducing the maximum draught, early January, because of low rainfall registered in Panama Canal watershed during December 2018.
In addition, low rainfall reached approximately the 90%, which is below the historical average. This resulted to the water levels in Gatun and Madden lakes dropping below the expected levels for 2019.
Vessels that arrive with draughts over 14.63 metres TFW will be allowed to pass after February 27. Yet, their transmit will depend on the actual level of lake Gatun.
In the meantime, if their transmit is impossible, the vessels will be required to trim or off-load cargo in order to be allowed to transit.
In conclusion, draught adjustments will be announced in 30.5cm (12 inch) decrements, generally with at least four weeks advance notice.