The effects of global warming on water supply in the United States.
More than 1,100 counties — one-third of all counties in the lower 48 — will face higher risks of water shortages by mid-century as the result of global warming. More than 400 of these counties will face extremely high risks of water shortages. – Natural Resources Defense Council
We can argue the accuracy of various models of temperature and precipitation, that likelihood is never science. Or we can agree that business-as-usual is a risk to water supplies.