I spoke to MacArthur “Genius” award winner Peter Gleick about water issues and drought. Above, he reminded us about the critical need for water to cool thermal (coal, gas, nuclear) power plants, and the comparison to renewables, which need none.
Below, Dr. Gleick on measures we can take to conserve and extend out water resources.

Nuclear plants were not shut down because of lack of water to cool them. They were shut down because of temperature limits put on the rivers and lakes where the heated water is discharged. There was one reactor that was shut down on the French Belgian border due to low water levels but:
https://www.aa.com.tr/en/europe/nuclear-reactor-in-france-shut-down-over-drought/1952943
I really have to wonder how Peter Gleick ever got a Genius award.
Hello?
That link describes a French nuclear power plant shut down in August 2020 due to drought conditions.
This describes the reactors shut down during the 2019 heatwave:
https://www.reuters.com/article/us-france-electricity-heatwave/hot-weather-cuts-french-german-nuclear-power-output-idUSKCN1UK0HR
The 2018 heatwave caused a shutdown.
Of course, the reactors in some cases could just still dump overheated water into the rivers, accelerating the fish die-off with what could then be classified as thermal pollution.