The suburban sprawl in the United States depends on the availability of water and power, among other resources. So what happens if the Colorado River, a source of water and power for numerous people, no longer can supply either?

Such an outcome — known as a “minimum power pool” — was once unfathomable here. Now, the federal government projects that day could come as soon as July.

Worse, officials warn, is the remote possibility of an even more catastrophic event. That is if the water level falls all the way to the lowest holes, so only small amounts could pass through the dam. Such a scenario — called “dead pool” — would transform Glen Canyon Dam from something that regulates an artery of national importance into a hulking concrete plug corking the Colorado River…

As the water has receded, so has the ability to produce power at Glen Canyon, as less pressure from the lake pushes the turbines. The dam already generates about 40 percent less power than what has been committed to customers, which includes dozens of Native American tribes, nonprofit rural electric cooperatives, military bases, and small cities and towns across several southwestern states. These customers would be responsible for buying power on the open market in the event Glen Canyon could not generate, potentially driving up rates dramatically.

The standard rate paid for Glen Canyon’s low-cost power is $30 per megawatt hour. On the open market, these customers last summer faced prices as high as $1,000 per megawatt hour, said Leslie James, executive director of the Colorado River Energy Distributors Association.

The issue of water has already increased concerns about development in the Southwest. A landscape full of single-family homes, lawns, lots of roads, and other suburban features requires a lot of water. Can life in sprawl not require as much water or is there a point where no more sprawl is just not possible? Then add in the issue of power. This includes transmission lines, homes, and other structures. Can the existing sprawl even be maintained with less electricity and water?

It also worth paying attention to how these changes with the Colorado River have ripple effects elsewhere. If as much water is not available, where can water come from? I imagine those around the Great Lakes have thoughts. If not as much power is generated, is there electricity capacity elsewhere? How much can be done short-term to shore things up while also considering long-term consequences?

More broadly, what might stop American sprawl? Not having water or power would be a powerful incentive. Others have speculated about a certain price of gas. Perhaps cultural beliefs about the suburban good life change. Or there might be something unforeseen. The conditions with the Colorado River might just offer a glimpse into what happens when sprawl has to stop.