I like to pay attention to books and articles on water allocation in countries such as Israel and Australia. The part of Texas in which I live is subject to frequent droughts, but during the past 75 or 80 years, we have not had to worry much about water use, aside from restrictions on lawn watering in the summer. Israel and Australia are ahead of us in such areas as desalinating soil and growing drought resistant food crops.
In central Texas, we can easily import food from other states in the USA or from other countries. But increasing shortages of water and salinization of irrigated soils could change this situation, as could more frequent droughts in other parts of the world. In my own garden, I have learned to conserve water by mulching, using drip irrigation, growing perennial crops that can get by with less frequent watering, incorporating trees that produce "light" shade, such as mesquite, into the garden and planting annual food crops in such a way that they get partial shade from the trees.
The article below is about allocation of water in Israel. One of the author's suggestions for conserving water is to reduce agricultural exports and eliminate subsidies for agricultural water.