Dams, Damned Dams and Double-damned Dams


The Salmon River is probably the longest undammed river in the Lower 48. at 425 miles long, it’s also the longest river wholly within one state in the Lower 48. Pretty much uniquely among Idaho rivers, the Salmon flows freely along its entire length.

It wasn’t always so; the main stem of the Salmon was dammed at Sunbeam, downstream from Stanley. The dam was built to generate electricity for gold mines in 1910. The mines went broke in 1911, and the dam remained in place until it was breached by the State of Idaho in 1934. Most of the dam remains in place today.

Breached Sunbeam Dam on the Salmon River, Sunbeam, Idaho

Breached Sunbeam Dam on the Salmon River, Sunbeam, Idaho

The Salmon’s torturous course begins at Galena Pass, at the south end of the Sawtooth Valley, at an elevation of about 9,000 feet.

Upper Sawtooth Valley from Galena Pass, headwaters of the Salmon River

Upper Sawtooth Valley from Galena Pass, headwaters of the Salmon River

The river manages to flow pretty much every direction on the compass along its course, and to be frothing white water along most of the way. It’s a white water rafter’s paradise.

Contrast the undammed Salmon with, say, the Payette River, with five major dams:  Black Canyon, Sage Hen, Paddock, Cascade, and Deadwood.. There are also several small impoundments and natural lakes with increased storage, such as the three Payette Lake dams.

Or the Boise River, with four major dams: Boise River Diversion Dam and New York Canal, Arrowrock DamAnderson Ranch Dam on the South Fork and Lucky Peak Dam.

There are seven dams on the Kootenai River (Kootenay in Canada), which barely qualifies as an Idaho River. It originates in Canada, flirts with the tip of the Idaho Panhandle before returning to Canada to join the Columbia River. The mighty Snake River which winds through Idaho flowing from Wyoming to Washington to join the Columbia River. The poor Snake has 15 dams along its length and ends in a Columbia River reservoir.

WC has mixed feelings about dams on rivers, salmon spawning rivers in particular. Dams are a potential source of hydroelectricity, a fairly clean form of electricity, although not all Idaho dams support turbines. Dams also allow agriculture in the desert Intermountain region. Idaho’s famous potatoes wouldn’t exist without irrigation, and irrigation wouldn’t exist without dams, or at least diversion dams. And dams undoubtedly reduce the risk of flooding, although humankind’s foolish propensity for building in floodplains makes that a necessity in the first place.

On the other hand, dams have very serious environmental impacts, too. All that irrigation means farming, farming means fertilizer, and fertilizer means contaminated runoff, that finds its way back into the river. Dams mean alteration of water temperatures and water chemistry, all of which hurts river plants and animals. They create lakes – reservoirs – where nature had created free-flowing streams.

And, especially, dams severely damage anadromous fish populations. Returning salmon and steelhead can’t get past the dams. Smolts headed to salt water get pureed as they go through turbines. Fish ladders can help with adults headed upstream, but it’s an imperfect technology. The Idaho Power Company attempted fish passage at its complex of three dams on the Snake — Hells Canyon, Oxbow and Brownlee — in the late 1950s, but these were unsuccessful. Subsequently, the company reached agreement with the Federal Power Commission to compensate for the loss of salmon and steelhead spawning habitat upstream of the three-dam complex by producing fish at hatcheries downstream of the dams. The problem with hatchery fish, of course, is that the genetic pool is so limited that eventually it is jeopardized by loss of diversity.

So it comes down to this: a tolerable dam is on a stream that doesn’t have anadromous fish. There are a few of these, icluding some in Alaska.

A damned dam is a dam that makes a reasonably successful effort to minimize the impact on spawning fish and ocean-bound smolts, with decent survival rates for both. A damned dam is one whose benefits justify the adverse impact on the environment; they are a necessary evil.

A double-damned dam is one that fails to accommodate anadromous fish, or does so through hatcheries, which are just a slower form of genetic doom for the fish species. A double-damned dam is one that offers insufficient benefits to justify the harm is wreaks on the environment.  Exhibits A, B and C in this category are the three Idaho Power Company dams in Hells Canyon on the Snake River, The Idaho Power attempted to construct fish passage at its complex of three dams on the Snake — Hells Canyon, Oxbow and Brownlee — in the late 1950s, but those were unsuccessful. Subsequently, the company reached a devils bargain with the Federal Power Commission to compensate for the loss of salmon and steelhead spawning habitat upstream of the three-dam complex – 75% of the Snake River drainage – by producing fish at hatcheries downstream of the dams. But fish hatcheries are a path to genetic death; instead of millions of fish breeding, only hundreds are pumped for eggs.

Double-damned dams need to be removed. WC isn’t the only person that thinks so, and it may be that eventually, like the Elwha Dam on the Olympic Peninsula,another double-damned dam, the three Hells Canyon Dams will be a footnote in history. WC and the anadromous fish of the Snake River certainly hope so.

 

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One thought on “Dams, Damned Dams and Double-damned Dams

  1. To my acknowledged imperfect understanding, you are correct that poor genetic diversity has indeed been a deviling problem for salmon in the Snake and Columbia River watersheds. It also, however, needn’t be that way – there are no unscalable impediments to maintaining a vibrant gene pool in hatchery-spawned anadromous fish.
    Thus, if I correctly have been told, robust salmon populations and hydroelectric dams needn’t be mutually exclusive. I absolutely am not, however, disputing your reporting of the status quo.

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