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George Reiger

Field and Stream May 1999

Can 100 feet of timber save a stream from ruin? Increasingly, it appears that the answer is no.

MANY ANGLERS--ESPECIALLY fly fishermen, who realize the importance of proper water temperatures, insect life, and silt-free conditions to a healthy water-shed have long suspected that the 30-meter (or 100-foot) protective margins mandated by most state and federal resource agencies along streams that are being timbered or developed are inadequate for protecting those streams from degradation.

No group is more emphatic about this than the Steelhead Committee of the Federation of Fly Fishers; and no region of the country suffers more from inadequately protected streams than the Pacific Northwest, home of the steelhead.

In January 1991, John de Yonge, editor of the Steelhead Committee's newsletter, described the result of recent heavy rains in Washington State: "The water gushed down the muddy slopes in vast sheets. On many [timber] cuts, it overwhelmed the cheap culvert systems federal and state regulators allow to be installed on logging roads. Logging slash--limbs, bark, foliage, broken logs--piled up in front of many culverts. A great head of water would form. Then it would burst the culverts, tearing a new creekbottom through the road and downhill on the naked slopes.

"Topsoil, already loose from the skidding and bulldozing of logging operations, poured downhill with the rush of water and the tumble of slash--downhill into' nearby creek beds.

"Many creeks that offer spawning gravel to steelhead, cutthroat trout, Dolly Vardens, and to coho and chum salmon experienced blowouts.

"A blowout occurs when landslides, usually caused by logging operations, dam a stream during these major storms. Behind the dam builds yet another big head of water and logging debris. Eventually the dam breaks--blows out ....

"A few reporters--damned few, it turned out--wondered whether the massive floods could be related to massive clear-cutting in the watersheds.

"'No, no, no, no!' responded the timber companies, state regulators, forestry-school academics and Forest Service spokespeople.

"'It's never been shown that clear-cuts allow more water to flow more quickly into streams,' they said.

"That, of course, is bushwa. Long ago, the Forest Service's own research branch did studies that showed that a relatively level clear-cut--much less one pitched at 60 degrees--does not soak up and retard water as standing forest does. Some studies showed that clear-cuts increased runoff by more than 30 percent."

THE 30-METER MYTH

Even if flooding never occurs in a logged watershed (a statistical impossibility), a 30-meter margin cannot screen a previously forested stream from new angles of exposure to the sun. When high winds knock down some of the remaining trees, those blowdowns open up additional gaps in the protective canopy. And when trees fall into a stream, they alter its flow and exacerbate siltation.

Since, however, loggers and developers want to utilize every tree or acre they can, the 30-meter margin evolved as a compromise that wouldn't overly penalize the loggers or developers but, at the same time, would appease environmentalists more concerned with the cosmetic appearance of streams than the diversity of life within them. Once this arbitrary distance was used on a few sites, it became the standard buffer size for all state and federal agencies charged with stream protection or regeneration. Although bureaucrats were satisfied with the 30-meter width, most conservationists remained skeptical that such a meager distance was doing anything more than putting a green patina on stream preservation.

LONG MEMORIES

A new study in the Proceedings of the National Academy of Sciences suggests the conservationists' skepticism is justified. Fred Benfield and his colleagues at Virginia Polytechnic Institute and State University in Blacksburg compared 12 Appalachian streams with 30-meter-wide erosion-control margins with 12 deeply forested streams and found that the buffered streams lagged far behind forested streams in the diversity and number of invertebrates and fishes living there.

That was not surprising. What was is that two of the forested streams also fit the depleted pattern. Using old aerial photographs, Benfield and his associates found that a majority of the land in these two watersheds had been farmed or pastured up until the 1950s. Although trees gradually took over the old fields and eroded pastures so that, today, both streams are widely wooded along their banks, these streams, still lack the biodiversity of other streams in the region that were never impacted by agriculture.

Stream ecologist J. David Allan at the University of Michigan in Ann Arbor says the new study proves "We've been kidding ourselves [about stream management]--hoping that protecting the margins will balance off adverse effects throughout the landscape."

Ecologist Stanley V. Gregory at Oregon State University in Corvallis adds that the new study suggests "There could be layers of effect that go back 200 or 300 years," and that streams have longer memories than their human neighbors, especially since so few people today live out their lives in one area.

Gregory and other residents of the Pacific Northwest find local waters impacted less by farming, ranching, mining, and even development than by the federal government in the guise of the U.S. Forest Service (USFS). Whenever the USFS is not actively promoting timber sales, road building, and the fallacy that 30-meter margins are adequate for protecting streams, this agency is ballyhooing the idea that it can enhance fish production with strategically placed logs, boulders, and gabions (rock-filled wire baskets).

While such structures undoubtedly help streams in dire need of improvement, the USFS' emphasis on enhancement has shifted focus away from its Congressional mandate of protecting watersheds to a policy that subtly questions the need for such protection. After all, if most any stream can be (allegedly) improved with backhoes, bulldozers, and hatcheries, why bother trying to preserve its pristine condition in the first place?

Obviously, mitigation, is better than nothing at all once the damage is done. But it means that conservationists must continually play defense to the government's own offensive strategies against nature. Wouldn't it be better to radically reduce the USFS' role as a timber broker and restore its mandate to protect watersheds? If that happened, we could still tolerate some logging in our national forests, but only after research determines exactly how broad a meaningful margin, should be.