Designing a Stream: Mother Nature's Little Helpers

Article excerpt

Scott and I are splashing up Portland Creek in hipwaders looking at logs the Forest Service has cabled to boulders all up and down the stream, as far as the eye can see. Old-growth forest stretches away on either side of us, part of a Spotted Owl Habitat Conservation Area set aside in the Willamette National Forest outside of Eugene. The water is low, exposing the surface of the streambed. The scarred logs are placed at carefully determined angles every few feet, some pointing upstream, some perpendicular. Cables bristle from their ends. It all looks like some sort of odd playground equipment. Behind us, a dozen men in red hardhats are standing in the stream drilling holes in boulders to anchor the log cables, the racket of the large drills filling the air. A couple of Forest Service supervisors stand around on the bank, scribbling on clipboards. What impresses me is both the incongruity of the sight - the ugly lashings beneath the huge alder and fir - and the scale of it, the sheer numbers of logs angled and tagged.

Earlier in the summer, giant excavators and rubber-tired skidders had powered up and down the stream, bringing in logs from other parts of the forest and boulders dynamited from a distant quarry. Equipment and crews of men were jumbled up everywhere, the creek-bed like a big-city construction site, full of shouting and exhaust fumes.

Decades ago and further upstream, Scott explains, loggers finished up a large harvesting operation by removing all the logs and woody debris from the water-standard practice for the timber industry then. The idea was to leave things clean. But scientists have discovered now that woody debris creates pools, "riffles," and "glides" that fish and other wildlife need to keep from being swept away. Wood creates "resistance," adds "roughness." It builds "structure." Sill logs and other kinds of logs dam up silt and gravel, too, which provide necessary spawning habitat. And the sill logs trap leaves and other organic matter which feed the insects that feed the fish.

The irony on Portland Creek is that it's against the law to cut trees in a Spotted Owl Habitat Conservation Zone, even for stream restoration. The logs have to be hauled in like steel girders. They have to be cabled to boulders, artificially fixed, to keep them from being washing away in the spring run-off: random debris replicated only through precise measurement, deliberate placement.

It was September as we walked up the stream, early fall leaves swirling over the structures Scott helped engineer. At the bottom of one deep pool - a "P 5" Scott labeled it - alder leaves shone like pennies. Scott is a "co-op" student with the Forest Service, studying for a master's in Fisheries and Wildlife at Oregon State, a good-looking man in his early thirties, quiet and considered. He had spent the summer working as a designated "stream designer" out of the Lowell Ranger Station, first counting the fish in the stream (shocking pools with an electro-shocker and counting the fish that floated up), then directing the "installation" of the logs according to a complex computer-generated map, then tagging and marking each log, carefully recording its position and purpose. At intervals he returns to see if each installation has met its "objectives," though eventually, if the project works, many of the logs will be buried by the silt and gravel they've built up.

The conceptual artist Cristo ringed a Florida island with sheets of pink fabric and later stretched a cloth fence twenty miles long across the fields of Northern California. As I unstrapped my hipwaders by the side of the jeep it seemed to me for a moment that the cabling of the logs and the designing of the stream was no less a kind of "environmental art," improbable, even absurd - and wonderful, too. It's hard not to admire something so apparently crazy.

I realize that the government's motives are not aesthetic or distinterested (neither are Cristo's; he makes a small fortune marketing swatches of his fabrics). …