Sujoy B. Roy, director for research and development (R&D), Tetra Tech Inc., Lafayette, US, and colleagues explain that population growth is expected to increase the demand for water for municipal use and for power generation beyond existing levels.

Global climate change threatens to reduce water supplies due to decreased rainfall and other factors compared to levels in the 20th century, the Journal of Environmental Science & Technology reports.

Roy’s group developed a “water supply sustainability risk index” that takes into account water withdrawal, projected growth, susceptibility to drought, projected climate change and other factors in individual US counties for the year 2050, according to an American Chemical Society statement.

Roy’s team used the index to conclude that climate change could foster an “extreme” risk of water shortages that may develop in 412 counties in southern and southwestern states and in the southern Great Plains.

“This is not intended as a prediction that water shortages will occur, but rather where they are more likely to occur, and where there might be greater pressure on public officials and water users to better characterize, and creatively manage demand and supply,” Roy said.

Unless, the authorities plan ahead for future, they will be in deep trouble is the report proves to be right.