The amount of freshwater available has shifted around the world. Since 2002, the amount of rainfall has not generally changed, but where the rain falls has. States with wet climates are experiencing more rainfall resulting in flooding. While dry climates are receiving less rain resulting in higher groundwater usage. The rate of groundwater usage is pushing an inevitable tipping point.
Some of these conditions are as a result of climate change, but a majority of water stress is from poor management. Groundwater is being pumped at unsustainable levels to irrigate crops and raise livestock in areas with an increasing population. This issue of "hot spots" or areas with less rain and depleting groundwater is putting pressure on the United States and the world.
Central Valley California, USA has been under a dry spell for over a decade. With less rain, more pressure is put on water tables resulting in companies having to drill deeper. Water tables are not able to replenish resulting in deeper drilling every year. Poor water management in the Great Plains, USA will undoubtedly drive global food insecurity. With less water available, higher food prices, shifts in crop selection, and changing food availability is the likely outcome. Difficult decisions are going to be made on whether to move water or move industry or agriculture.
The rapid change to water resources is not only a significant threat to society but also to governments and politics. Water has no political boundaries or borders. Groundwater depletion and glacial disappearance will threaten the livelihood of billions. Water refugees will travel to new areas to find water, something already occurring and well understood from the Syrian Wars.
By looking at some of the most developed countries, we can see how water stress is beginning to affect them now.
South Africa has already planned for "Day Zero." It is expected that water resources will run out and all taps will be shut off. People will have to wait in line at collection points for rationed water that might not be clean.
In Mexico City, residents are already used to water being turned off for part of the day while one in five residents only receive 2-4 hours of clean water a day. Their infrastructure is beginning to crumble resulting in 980 liters of water lost to leaks.
In 2015, Rio de Janeiro, Brazil had its main reservoirs fall below 4% capacity. As a result, the government began supplying emergency water trucks. The need for water became so desperate, civilians started to loot the emergency water trucks sent. The reservoir has now fallen back to 15% which could result in more clashes.
Over 97% of Egypt's water comes from the Nile River. As agriculture and industry increase, so does water contamination. As a result, Egypt is expected to have severe water shortages before 2025.
Finally, the UAE is in such severe water shortages that they are planning to tow an iceberg that is 5,500 miles away in Antarctica that has the capacity of 20 billion gallons of fresh water. The towing process is expected to take 1 year.
Famiglietti, Jay "Emerging Trends in Global Freshwater Availability" May 2018 University of Saskatchewan, Canada