Interesting read.
It sounds like the environmentalist version of Chinatown, the film was inspired by the California Water Wars at the beginning of the 20th century, which Los Angeles interests secured water rights in the Owens Valley.
In this “updated” version, John Huston’s Noah Cross is the evil environmentalist stealing water from the rightful farmers who own it to support their failed and failing scheme to return California to the natural state it never was. At least in the film, Huston’s character was competent. Evil but competent.
How many farmers lives were destroyed when they turned off the water? Same tactics they used in the forest industry and the auto and oil industries. Fake an environmental disaster to shut down an industry.