The opening of “Holy Water,” Joan Didion’s 1977 essay about H2O, a scarce and precious thing in Southern California, with its endless summer, omnipresent swimming pools and expansive deserts:

Some of us who live in arid parts of the world think about water with a reverence others might find excessive. The water I will draw tomorrow from my tap in Malibu is today crossing the Mojave Desert from the Colorado River, and I like to think about exactly where that water is. The water I will drink tonight in a restaurant in Hollywood is by now well down the Los Angeles Aqueduct from the Owens River, and I also think about exactly where that water is: I particularly like to imagine it as it cascades down the 45-degree stone steps that aerate Owens water after its airless passage through the mountain pipes and siphons.

As it happens my own reverence for water has always taken the form of this constant meditation upon where the water is, of an obsessive interest not in the politics of water but in the waterworks themselves, in the movement of water through aqueducts and siphons and pumps and forebays and afterbays and weirs and drains, in plumbing on the grand scale. I know the data on water projects I will never see. I know the difficulty Kaiser had closing the last two sluiceway gates on the Guri Dam in Venezuela. I keep watch on evaporation behind the Aswan in Egypt. I can put myself to sleep imagining the water dropping a thousand feet into the turbines at Churchill Falls in Labrador. If the Churchill Falls Project fails to materialize, I fall back on waterworks closer at hand — the tailrace at Hoover on the Colorado, the surge tank in the Tehachapi Mountains that receives California Aqueduct water pumped before — and finally I replay a morning when I was seventeen years old and caught, in a military-surplus life raft, in the construction of the Nimbus Afterbay Dam on the American River near Sacramento. I remember that at the moment it happened I was trying to open a tin of anchovies with capers. I recall the raft spinning into the narrow chute through which the river had been temporarily diverted. I recall being deliriously happy.•