Map: The United States of Watersheds

When American settlers moved westward in the 19th century, they went in search of precious gold, furs and land. But today, as the West booms, there’s another limited commodity that states need to carefully ration: Water.

John Wesley Powell saw this coming. The 19th century geologist and explorer, who navigated the Colorado River in 1869 and 1872, realized that the limited water in the arid West would eventually lead to conflict between the states. Therefore, he suggested the boundaries of Western states be determined by watersheds — the topographical basins that funnel surface water to a single exit point.

Why use watersheds to draw boundaries, instead of the sometimes-arbitrary, sometimes-geographical boundaries for states? Water usage, especially along the Colorado River, is the subject of innumerable state vs. state lawsuits, strict rationing and increasing conflict between urban areas and agricultural industries. Sorting states by watersheds would force the individual states to make their own decisions balancing water usage, rather than fighting among themselves. And those states would be able to use water within their own boundaries, rather than shipping water tens, even hundreds of miles away.

John Lavey thought that was a pretty good idea. So Lavey, a land use planner at the Sonoran Institute in Bozeman, Mont., set about to recreate Powell’s vision — but this time, instead of stopping in the West, he crossed the Rocky Mountains. Sticking with a maximum of 50 states, here are the boundaries Lavey drew, dictated by North American watersheds:

Some major differences with our map today: Missoula would fall in Idaho, not Montana. Las Vegas has water patterns in common with Utah and Arizona, but not Reno and Tahoe. Denver fits better with most of Kansas than with Colorado communities west of the Rockies. Almost all of Ohio, aside from the Great Lakes region, has water interests in common with Kentucky and West Virginia. And New York City gets lumped in with northern New Jersey, thanks to the mighty Hudson River.

Lavey says drawing these borders would have a few positive consequences. Transportation hubs tend to be in low spots in watersheds — we build our roads to “follow rivers, not ridges,” Lavey writes. “In their present day configuration, state transportation departments sometimes have to maintain roads that they access through adjoining states, or form maintenance agreements with other states to maintain their roads for them,” he writes.

And each watershed’s ecosystem is unique. If a state’s boundaries follow the watershed, they would be able to streamline land and wildlife management.

We doubt states will be redrawing their maps any time soon, but it’s an interesting thought experiment: Plenty of state borders are formed by seemingly arbitrary state lines. What if we had let geography and terrain define our boundaries?

Here’s another version of Lavey’s new United States: