least wide, permitting Post-Panamax vessels to navigate in a single direction. Maximum operating level of Gatun Lake Canal elevations are referred to using the Precise Level Datum (PLD), which is close to the mean sea level of the Atlantic and Pacific entrances. The maximum operational level of Gatun Lake was raised by approximately from the previous PLD level of to a PLD level of . Combined with the widening and deepening of the navigational channels, this has increased Gatun Lake's usable water reserve capacity and allows the canal's water system to supply a daily average of of additional water. This additional water volume is enough to provide an annual average of approximately 1,100 additional lockages without affecting the water supply for human use, which is also provided from Gatun and Alhajuela Lakes. Construction timeline The construction of the third set of locks project was originally slated to take seven or eight years, with the new locks beginning operations between fiscal years 2014 and 2015, roughly 100 years after the canal first opened. In July 2012, however, it was announced that the expansion project had fallen six months behind schedule, pushing the opening date back from October 2014 to April 2015. By September 2014, the new gates were projected to be open for transit at the "beginning of 2016." In October 2011, the Panama Canal Authority announced the completion of the third phase of excavation for the Pacific access channel. In June 2012, a 100-foot-tall reinforced concrete monolith was completed, the first of 46 such monoliths that line the new Pacific-side lock walls. Sixteen new lock gates had to be installed as part of the canal expansion: eight on the Atlantic side, and eight on the Pacific. The installation process began in December 2014, with a 3,285-ton gate's installation on the Atlantic side; it concluded in April 2015, with the installation of a 4,232-ton gate on the Pacific side. In June 2015, flooding of the new locks began: first on the Atlantic side, then on the Pacific; by then, the canal's re-inauguration was slated for April 2016. In August 2015, a crack was reported in a concrete sill at the new Cocoli locks, but it was not initially anticipated to affect the project completion timeline. By November 2015, however, cracks discovered over the previous months threatened to delay project completion. Sill reinforcements were, however, anticipated to be completed by January, 2016.