Los Angeles is a city that isn’t meant to exist. Approaching the metropolis by land you pass through desert. It’s dry, hot and arid. The only natural vegetation is that which clings to the sea-facing mountains, fed by mist that burns off as it travels inland. The water that feeds the palm trees and swimming pools—and which extinguishes the annual fires that the city is known for—is pumped hundreds of miles via the Mulholland Aqueduct, a scandalous piece of infrastructure that left a once-verdant valley to the northeast barren. Water—and drought—are as much a part of the story of Los Angeles as celluloid and freeways.

Endless summer, here, translates to endless drought. One drought in particular, which lasted from 1976 to 1977, was particularly momentous for American culture....