Climate change is only part of the problem. The other part is increasing demand for things like fresh water. Economic growth.

Climate change is like a two edged sword. It's both the increasing demands of economic and population growth, plus disruptions in supply, created by climate change itself.

The Colorado River is a prime example. From what I read, drought, related to climate, accounts for around a 20% reduction in river flow. That, by itself, wouldn't be so bad except demand for water increases from population and economic growth in the region.

Technology and conservation has helped, but another part of the problem is that they over committed the river, even back when water rights were being divvied up years ago. They thought there would be more water than there was. It's a two fold problem. Climate change plus growth in demands.