Changing weather patterns and global warming are affecting water supply for one of the world’s most important waterways, the Panama Canal, and access to drinking water for millions of Panamanians, reports Grace Livingstone.

Among the greatest engineering feats of the 20th century is the Panama Canal.

A man-made waterway linking the Pacific and Atlantic Oceans was completed in 1914, halving travel times between the West Coast and Europe.

In order to overcome the difference in height along its 50-mile (80km) length, ships still have to pass through locks. Before being lowered again, they are raised to an altitude of 85 feet (26 metres).

Mahelis de Garc’a, a Panama Canal guide, explains that the canal’s locks raise vessels by releasing huge amounts of water from artificial lakes at the top of mountains.

As global warming affects weather patterns, operating the canal is becoming increasingly difficult.

Compared to historic average rainfall, 2019 was Panama’s fifth driest year in 70 years, according to the Panama Canal Authority.

Nevertheless, heavy rains can also create problems, as they can cause the artificial lakes to overflow in dry years.

The canal will have to find new sources of water and new methods of storing it as dry years and storms become more common.

Whenever a ship passes through the locks, 55 million gallons (250 million litres) of fresh water are used. More than 2 billion gallons (9 billion litres) of fresh water are used every day by 37 ships passing through the locks.

In rainy years, canal authorities are looking for ways to store more water so that they will have a sufficient supply in drier ones.

A feasibility study is being conducted on a number of options, including deepening existing artificial lakes.