It's a story as old as the west and as recent as the last drought: a fight over water allocations when there's not much water, period.
In the summer of 2022, the Anderson-Cottonwood Irrigation District south of Redding got just a fraction of its normal allotment of Sacramento River water. The story is told in the film by local film producer T.L. Greene. He and director Tyler Faires talk about the water shutoff and the reaction to it.
By the way, it's not as corrosive as it sounds: ACID stands for Anderson-Cottonwood Irrigation District.