THE BURNED OVER DISTRICT

This time it is the Rio Grande, which may soon be called the Río Minúsculo.

On maps, the mighty Rio Grande meanders 1,900 miles, from southern Colorado’s San Juan Mountains to the Gulf of Mexico. But on the ground, farms and cities drink all but a trickle before it reaches the canal that irrigates Bobby Skov’s farm outside El Paso, hundreds of miles from the gulf.

Now, shriveled by the historic drought that has consumed California and most of the Southwest, that trickle has become a moist breath.

“It’s been progressively worse” since the early 2000s, Mr. Skov said during a pickup-truck tour of his spread last week, but he said his farm would muddle through — if the trend did not continue. “The jury’s out on that,” he said...

The perils of drought are on ample display along the Rio Grande, where a rising thirst has tested farmers, fueled environmental battles over vanishing fish and pushed a water-rights dispute between Texas and New Mexico to the Supreme Court.

But you can also see glimmers of hope. Albuquerque, the biggest New Mexico city along the Rio Grande, has cut its water consumption by a quarter in 20 years even as its population has grown by a third. Irrigation districts and farmers — which consume perhaps seven of every 10 gallons of river water — are turning to technology and ingenuity to make use of every drop of water given them.

John Fleck, a journalist and scholar at the University of New Mexico Water Resources Program who is finishing a book on the Colorado River, said no one should dismiss the gravity of the West’s plight. But neither is it necessarily ruination.

“This whole running-out-of-water thing isn’t really doom,” he said. “When water gets short, farmers get very clever.”

An untamed, flash-flooding home to sturgeon and eels a century ago, much of the Rio Grande today is little more than a magnificently engineered pipe — diverted, straightened, dammed, bled by canals, linked by tunnel to the Colorado River basin in the north, surrendering its last trickle in the south to a ditch that supplies farmers near El Paso. Only miles later do Mexican tributaries renew its journey to the gulf. Its raison d’être is to sustain the booming society along its banks.

At least it is able to reach the Gulf of Mexico, thanks to its Mexican tributaries. Thanks Mexico.