Complex sentence: The daily hours of operation on the days the canal is open here also cut back, with closure at 6:00 pm each day until August 11 when the closing time fell back to 4:00 pm.
Split into simpler sentences: The daily hours of operation on the days the canal is open have also been cut back. The canal will now close at 6:00 pm each day until August 11 when the closing time will fall back to 4:00 pm.