Runoff And Drought

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This photo of Magic Reservoir, taken in August 2021, shows the effects of extreme drought in southern Idaho. Prospects for drought relief in 2022 are, at present, not looking good. Photo credit: Ryan Hartman

BY HANNES THUM

Water has been scarce lately. We’ve been experiencing the effects of different degrees of serious drought over the past few years, and water users in our region have already been planning ahead for how they can continue (if they’re lucky) irrigating land this coming summer.

Which is an odd thing to think about, considering that we just finished up one of the wetter Aprils on record here – scarcity has not been the word that a lot of people would use. For those in our community who would prefer sandals and sunscreen to raincoats and boots, the common refrain around town seems to be, “when is spring actually going to start?”

Which is usually followed closely by, “at least we’re getting the moisture.”

It’s no secret that we live in an arid part of the world here. But it’s also no secret that the last few years have been abnormally dry, and that we are heading rapidly into another summer of noteworthy drought (the question of when something noteworthy becomes no longer noteworthy is another conversation for another time).

So, this wet spring will help things, but it won’t solve things. Not even close, really. Because the spring rains have helped and will help fill the bucket, so to speak, but the main issue is that a bucket is an inadequate metaphor for how water works in our valley.

Water moves in complex ways across, through, under, above, and within our landscapes. It moves across the surface in streams and rivers but it also moves below the surface in ways that we are just beginning to understand. Not every drop ends up where one may think it ends up. It percolates, it evaporates, it circulates. Water enters and exits and flows through these systems in time scales that go beyond just a single season.

So, a bit of rain can help, but a bit of rain is an incomplete solution.

At some point this spring, snow in the high country will begin to melt faster and faster and the rivers will rise significantly. We have seen a couple of pulses on the Big Wood, one in late March and one in the first week of May, but we will see a bigger one whenever spring “actually starts.” That peak flow will almost certainly be much lower than what we might hope for, and the season of runoff will almost certainly be shorter than we would wish. Remember how hot and dry August can be? We will see what happens.

Life as we know it revolves around water. If there’s extraterrestrial life out in the universe that exists without water, we certainly don’t know about it. When we look for and talk about life in other places, we really are looking for places that might have water – everything we know about how life works is based on water. And this matters here, on Earth, a great deal. The tiniest ant and the largest cottonwood, the sagebrush and the farmers’ barley (and you and me) only live here when there is water to allow it. Where the water goes, so goes life.