Does a River care if it doesn't get to the Ocean?
By George SibleyI’ve been riparian to a lot of rivers and streams, but it was a long time before I began to think about what a river is, what it is doing.
Most of my life I have lived in the Colorado River Basin, the main river system of the Southwestern United States; but I spent my early years back East, in what an Easterner might call the land of “real rivers.” French Creek, which joins the Allegheny River in my Pennsylvania hometown, is about as big on average as the Colorado River gets in Colorado; and the Allegheny River, at its junction with the Monongahela to create the Ohio River — still more than a thousand miles from the ocean — runs as much water on average as the entire Colorado River. Last year I stood at the point of land where the Ohio River joins the Mississippi, and was basically just stunned, so much moving water — then tried to imagine it in topping the levees we saw in its episodic floods. I couldn’t.
But despite a fair amount of splashing around in those back-East streams and rivers, building dams on the little ones, trying to skip stones across the big ones, and just staring at the biggest ones, it wasn’t till the day I got a sudden overview of the East River — a modest little mountain “crick” in back-East terms that is tributary to the Gunnison River, which is tributary to the Colorado River — that I began to think about what a river really is, and what it really does.
That was my first summer in the valley of the Upper Gunnison River, in Western Colorado. One brilliant June day — still early spring in the upper reaches of the valley — I took an afternoon off from my brand-new Crested Butte newspaper, got out my ten-speed skinny-tire bike (no mountain bikes then), and headed up the hill past the ski area, on up to the ridge separating Crested Butte’s Slate River valley and the adjacent East River valley. I’d only been in Crested Butte during the winter to that point, and had never been out into the surrounding mountains and valleys.
But the dirt road had just been plowed open that week, and was a muddy mess; feeling the slop spun up by my tire soaking through my shirt, I revised my earlier idea of riding the five miles to the Rocky Mountain Biological Lab in the old mining camp of Gothic, but I decided to slosh on to the edge of the ridge to see what there was to see of the next valley —
And found myself looking five hundred feet down a steep slope to a watercourse that I could only see at first as “lost.” A lost river wandering around on a flat-bottom, brushy, marshy valley floor, pregnant with brownish-blue water winding in loops and bends, often almost doubling back to where it had just been, a lost river trying to find its way downhill with outliers everywhere of abandoned ponds.
It was beyond beautiful, looking down on that liquid abundance — and a longer look suggested that maybe it wasn’t really lost at all. It was just dawdling — yes, dawdling; the river was dawdling, loafing, goofing around — acting like maybe it just didn’t want to leave. And who could blame it, that day? Like old Walt: I loaf and invite my soul. So it seemed to say, and you’re crazy if you aren’t doing the same somehow.
But that moment was where the question slipped into my mind: What is this water doing? And if it is doing what rivers, do, then what is the river, any river, doing?
In its most general sense, a river is a flow of anything, from very cold gases to very hot rock that cannot be directly absorbed where it is and, consequently, obeys gravity by flowing off to lower environments until it finds a place from which some geographic destiny conspires against it seeking any lower spot. For water, the default destiny is usually the ocean, but many rivers on the continents around the world end in interior lakes, where inflow equals evaporation — or just disappear into underground “sinks,” great groundwater aquifers. Both of these occur in the Great Basin of Utah and Nevada, and other desert places.
But what makes a river different from other flows? Ditches, storm sewers and the plumbing in your house are all flows of water too; how are they different from rivers? From a strict engineering perspective, a river could just be considered a natural storm sewer – a way of ridding the land of excess water: more moisture falls on the land than the land can absorb, and the river carries off the excess. Indeed, engineers often treat rivers like storm sewers, channeling them into concrete ditches to move them through some place where they are mostly inconveniences requiring bridges and disrupting the beauty of straight-line grids. The Los Angeles River through its city is an example — basically a big concrete ditch.
But do rivers demonstrate the kind of efficiency that engineers design into effective storm sewers or other forms of plumbing? Look closely at a river, and you see a very different behavior.
Water falling over land has two choices: soak in or run off, and its first choice clearly is to soak in. When it soaks in, it keeps moving, but slowly, trickling through the soil as groundwater, maybe eventually making its way to a river, but maybe also either working its way up into a plant through roots or sinking far down into an aquifer where it might stay forever, or until someone builds a city over it and starts pumping it; major cities around the world today are mining water that’s been being deposited incrementally for millennia.
But when too much water comes down too fast for all of it to sink in, it has no other choice but to run off downhill, and here in the mountains there often seems to be a kind of tearing rage to the water, an erosive umbrage grinding away at anything that dares thrust itself above some hypothetical global sea level. But looked at another way, water running off of steep land does exactly what a human falling out of control on a steep slope would do: it grabs at everything it can to slow and stop its descent. It pulls at dirt, sand, pebbles, twigs and leaves, rocks, trees — and everything that can’t help the water by holding it back is torn loose and carried along with the water.
That torn-up material either floats along suspended in the water or rolls and bounces along the bottom of the water’s course, and it is carried along until something causes the river to lose velocity — a lesser gradient of flow, or the turbulence of another flow joining it, or a more sinuous course, or just the rough turbulence caused by its own growing load of material. As the velocity of the flow drops, so does the ability of the flow to carry material, and the water drops what it is carrying in its own path, forcing itself to slow even more and find its way through or around its own debris. If the shape and slope of the land don’t allow the water to sink into the ground, then the river gradually rearranges the land until it can.
The discharge of a river — the amount of water flowing past any point — is a measure of three factors: the breadth, depth and velocity of the flow as set by its gradient of fall. And common sense indicates that, for a river flowing now faster, now slower, through a changing landscape, these three factors must respond in a kind of overall mathematical constancy — that is, if one of the factors decreases, then one or both of the other factors must increase accordingly. If it has piled enough stuff in its own path to decrease the gradient and its velocity, then the river must become deeper or broader, or spread itself around in slow loops and whorls. If the river gets pinched down into a canyon that decreases its breadth, then it either has to get deeper or its velocity must increase, or both.
A mountain river that has torn up a lot of debris in its high-velocity steep gradients has a lot to spread in front of itself when its gradient and velocity diminish, and it eventually creates a broad flat floodplain like the one I found myself looking down on that day on the road above the East River.
There in a mature floodplain, the behavior of a river violates every engineering notion of the efficient removal of excess water from the land. The river winds and snakes back and forth across its floodplain in long loops, pushing along ever more debris to obstruct its own passage from the land. Its loops and bends enlarge outward, as the water cuts the banks on the outside of the curve and deposits sand and gravel on the inside of the curves, until eventually the loops cut into each other, cutting new dynamics of flow and leaving oxbows of stranded water that gradually grow into marshes. It also hides away a lot of its water as alluvial groundwater — hiding it from the sun.
In general, then, I conclude that a river allowed to seek its own course will do what it can to alter geography in ways that thwart its water from leaving the land. All rivers might flow into the sea, as the Biblical philosopher claimed, but there’s evidence in the way they work, that they are in no hurry to do so, and maybe would rather not.
A Gunnison Basin rancher told me the rancher’s impossible dream: “We want to turn our ‘watershed’ into a ‘catchment basin’.” The distinction should be obvious enough. I’ve come across small mini-valleys in the Colorado River’s headwaters that actually have almost become catchment basins: aspens, thick grasses and willow stands show that these “hollows” are well watered; yet there is no surface flow of water. But dig down into the tough grasses and you find wet black earth; the hole you dig will eventually fill with water that is trickling through the soil. Ultimately, of course, even these little catchment basins begin to shed their water; springs and waterholes erupt where the soil can no longer hold all the water trickling underground; little streams form, and the water leaves the land. But not for want of trying not to.
This leads to what is probably water’s most complex strategy for staying with the land: life itself. From a most elemental perspective, all land-based biological life could be defined as a highly diversified joint strategy between water and earth, to keep water on or in the land. Life, from this elemental perspective, is just a stacking up and connecting of minute water vessels, each filled with a soup of water and dissolved earth-elements; without the water, the container is without life; add water and life stirs.
So all biological life, in this sense, is a way for water to bank itself against the pull of gravity — through plants, water actually thrusts itself up directly against gravity, to heights of as much as three hundred feet in the greatest trees. And through us animals, water moves all about the landscape, uphill, downhill, underground, or just stubbornly staying in place. Beavers build dams to back up shallow ponds that gradually fill in with sediment and plant decay, creating rich soggy meadows.
We humans are water that has figured out how to stand up and look around, think and dream — to dream, among other things, of watersheds turned into catchment basins. We’ve gone far beyond the beavers in figuring out how to slow the water’s passage from the land, spreading it out over its own floodplains to grow more life, moving it through increasingly complex labyrinths of plumbing to water more people (more than the earth probably needs), pooling it up behind dams to put it to work for us — asking it to stand in and push rather than cut and run.
Something in our own nature makes us think (once we’ve come to take for granted the work its water does for us) that the river would rather run free than be pooled behind a dam. Certainly the aquatic and riparian life systems that grow up in and around moving water would rather see the water moving, and those systems get supplanted by other life systems when it doesn’t; but what of the river itself?
Water does become something else when a river disappears into the “holding action” of a lake or a reservoir or the oceans. It continues to move around restlessly — the great oceanic currents dwarf even the largest of land rivers – but everything from the way it moves, what drives its movement, and the life it nurtures is different, a different world, and I’ll leave that exploration to Jacques Cousteau or whoever wants it.
Suffice it to say, for present purposes, rivers disappear in the oceans, and in reservoirs too — die there, in a way; even though water comes out through the dam below the reservoir, it is no longer the same river. For water that has been part of a river, reservoirs and oceans must be like consignment to a waiting room, with the only escape via the sun — being sucked out of the still water and carried out over land to fall again to begin the long process of trying not to go downhill too fast.
I think of that when, for example, people repeat this truism about the Colorado River: “It’s so heavily used that most years its water never reaches the ocean.” So? Watch the river flow through the land, watch the water at work on its own, and you’ll find no real reason to think that’s a bad thing from the water’s perspective: what’s so great about going into the sea? A big salty waiting room where water waits for the chance to rise up cleansed and pure and again move out onto the land.
On the other hand, it’s too bad the Colorado River no longer reaches its own delta, just before the sea, with any volume — that beautiful lush oasis of fecundity and diversity Aldo Leopold described for us a century ago, now mostly gone. That was the river’s last hurrah — a delta it kept growing and growing in its unconstrained days, as if it wanted to carry all the land above water down to fill up the whole sea with its land-based freshwater life. And up against the beautiful diversity and intensity of that delta, it is hard to view with a similar joy the extensive but less diverse “delta” over which the river is spread today, from the Phoenix-Tucson area on the east, through the monocultures of western Arizona and the Imperial Valley, to the Los Angeles area on the west. It may be the world’s largest spreading-out of a river’s end, but things may be getting spread a little too thinly there for quality as well as quantity in the life the river waters in that man-made delta.
That’s a long run in the imagination, from looking down on the East River, high in the Colorado River’s headwaters that sunny soggy spring afternoon forty years ago this summer, to the distant delta of the Colorado — a river that now dies a number of deaths by dam en route, but will someday have resurrected itself, overtopped and removed the dams and recommenced the construction of a delta built from the removal of the Colorado Plateau, and eventually the Rockies. Meanwhile, as water organized to think and dream, I recommend more riparian loafing by moving waters trying not to move through too fast.
MG
