Jason Heid

Towering hundreds of feet above the dunes of Boca Chica Beach, an American flag the size of a two-car garage ripples dramatically, hung from a crane beside a pair of launchpad towers built for the largest rockets ever constructed. In the fading sunlight, it’s a properly patriotic backdrop for the squat stage serving as the center of today’s Fourth of July celebrations. A live rock band gives way to a young local singer with a surprisingly mature voice.

Moisés Vargas Terán remembers the odd remedies ranchers once used to battle the New World screwworm. In Mexico, they’d rub traditional herbs on wounds into which the insect had burrowed to lay eggs so that its larvae could feast on the living tissue of cattle. Some U.S. livestock producers, meanwhile, poured engine oil on the cuts. The larvae would seep out—but then crawl into the soil and emerge later as flies.

Chris Cuellar’s eyes scan the eight-inch pipe that’s spewing water on the other side of the chain-link fence. Drawn from hundreds of feet below the surface, the water tumbles down a short spillway that leads straight into the Nueces River. It will flow roughly five miles downstream, to the intake pipes of the City of Corpus Christi’s O. N. Stevens Water Treatment Plant. From there, a vast network of pipes will carry it to homes and businesses.