Canal De Panamá, Panama

Gatun Lake is filled with rainwater, and the lake accumulates excess water during wet months. The water is lost to the oceans at a rate of 101,000 m3 (26,700,000 US gal; 22,200,000 imp gal) per downward lock cycle. Since a ship will have to go upward to Gatun Lake first and then descend, a single passing will cost double the amount; but the same waterflow cycle can be used for another ship passing in the opposite direction. The ship's submerged volume is not relevant to this amount of water. During the dry season, when there is less rainfall, there is also a shortfall of water in Gatun Lake.
As a signatory to the United Nations Global Compact and member of the World Business Council for Sustainable Development, the ACP has developed an environmentally and socially sustainable program for expansion, which will protect the aquatic and terrestrial resources of the canal watershed. After completion, expansion will guarantee the availability and quality of water resources by using water-saving basins at each new lock. These water-saving basins will diminish water loss and preserve freshwater resources along the waterway by reusing water from the basins into the locks. Each lock chamber will have three water-saving basins, which will reuse 60% of the water in each transit. There are a total of nine basins for each of the two lock complexes, and a total of 18 basins for the entire project.
The sea level at the Pacific side is about 20 centimeters (8 inches) higher than that of the Atlantic side due to differences in ocean conditions such as water densities and weather.