Looking at Streams: When Poetry Hits Engineering

A lovely stream dances and sparkles down the side of a mountain meadow. Sunlight glints off the wet rocks in the cold water, and in a few still, tree-shadowed pools, the flash of a shadow hints at the presence of trout. A few water striders scoot over the surface. Farther downstream, the little brook slows and spreads gaining the title of River and picking up a little silt, no longer cold and diamond clear but a touch muddy, especially after rain. It winds slowly, starting to meander across the plateau that sits between the mountains to the west and the broken, mesa-capped plains to the east.

Or I could say that the stream went from a Rosgen Aa2+ in a Type II valley to an A/II and then a G4/VIII.

Which description is better? It depends: are you a poet or an engineer? Because both paragraphs mean the same thing.

I’ve mentioned before that my academic field is environmental history. Environmental historians tend to find that their course work strays from the usual historical fold. I’ve known people who took courses in veterinary science (was writing about horses and mules), civil engineering, wildlife management, forestry, fire science, and in my case, river restoration and landscape architecture. River restoration has changed over the years, from focusing on getting the chemicals and sudsy stuff out of the water, to trying to make the landscape as close as possible to what it was before Anglo-Americans started channelizing the stream. In order to “put it back,” you have to be able to describe the stream. Which leads to problems.

If I were to describe something as a “blue ribbon trout stream,” most civil engineers and landscape designers will tip their heads to the side and do an impression of a slightly confused dog. Or will nod, take notes, and wonder what on Earth they are supposed to do with that.

Here fishy, fishy, fishy.  From www.images.summetpost.org

Here fishy, fishy, fishy. From http://www.images.summetpost.org

A number of people developed ways to describe creeks, seeps, streams, and rivers, all useful in certain ways, and all with flaws. There are a number of variables to a stream, some of which you can tell from a good photograph or map, some that can only be determined from personal observation and looking at flow records. And rivers shift over time and space, as described in the opening paragraph. So what do you do in order to get everyone singing off the same sheet of music?

A gent named Dave Rosgen developed a system that is now used by most restoration consultants, the US Forest and park services, and other groups to describe a stream. I’ll spare you the physics and details (or you can go buy his book, Applied River Morphology) but it starts with a very general description that you can get from measuring things on a topo map. Then it becomes more and more detailed. So now, I can look at, say, the Dry Cimmaron River near Kenton OK and say, “the streamreach of interest is a C 5 VII” and everyone knows exactly what I’m talking about and they can see it in their minds’ eyes. It is efficient, effective, and absolutely unpoetic.

After taking that course on river restoration, I discovered that I’ve started classifying and categorizing bodies of water without thinking about it. My eyes start tracing the stream, looking for cut banks and sandbars, riffles and pools, the edges of the banks and floodplains (so I can see where bank full discharge is, because “If you don’t know bank full discharge, you don’t know sh*t”), and trying to determine what the bed material is. What alterations have been made? When was the last BFD event? What was it like before? Is it a bedrock controlled stream or is it downcutting? Agrading? Channalized? How would I restore it to a typical streamreach for this life-zone and topography? Meanwhile normal people say, “Oh, that’s a pretty creek. Look, minnows!” SIGH.

Bedrock controlled stream at a knickpoint into a pool . .  aka Folsom Falls on the Dry Cimarron River, NM. From WikiCommons.

Bedrock controlled stream at a knickpoint into a pool . . aka Folsom Falls on the Dry Cimarron River, NM. From WikiCommons.

I don’t really mind having Engineering Vision. it is very useful in my writing work, and it gives me a common language to use when talking to engineers, park rangers, and other river people. But it does change what I see in the landscape, and in some ways, how I see the landscape. You see a waterfall. I see a knickpoint and bedrock control of stream development. You see a river valley with three levels that drop to the river and I see four terraces, marking different points of erosion and stabilization, possibly related to climatic episodes or glaciations. Or to geomorphic uplift, as happened to the Canadian River Gorge in NM.

‘Tis an interesting way to see the world.

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