[env-trinity] Mailtribune opinion- A dam bit of difference: the Klamath debate

[Tom Stokely]

A dam bit of difference: the Klamath debate


http://www.mailtribune.com/apps/pbcs.dll/article?AID=/20111120/OPINION/111200317/-1/NEWSMAP 
By Bill Cross
Not all dams are created equal. Each is endowed by its creators with certain abilities: Some provide flood control, some store irrigation water, some generate hydroelectricity, and many — like the one at Lost Creek Reservoir on the Rogue River — are engineering compromises that do a bit of all these things.

If we're going to debate whether to remove a dam, we need to know precisely what it does. Right now the nation's hottest dam-removal debate centers on whether to dismantle four PacifiCorp dams on the Upper Klamath River. Yet many people don't understand what these dams can — and cannot — do. The fact that the dams are owned by PacifiCorp, an electric power company, should be a big clue. PacifiCorp is not in the business of providing flood control or storing irrigation water for farmers. PacifiCorp generates and sells electricity, and making electricity is the only thing their Upper Klamath dams were designed to do.

This surprises most people. They assume that all dams reduce flooding in winter and boost the river's flow during the long dry summer. But to do those things, a dam must be able to store and release large amounts of water by raising and lowering the reservoir behind the dam. At Lost Creek Reservoir on the Rogue, the Army Corps of Engineers releases extra water every summer, lowering the reservoir dramatically, then uses that excess space to capture high flows during winter and spring, refilling the reservoir in time for the next summer dry season.

Not so with PacifiCorp's Klamath dams. Seasonal raising and lowering is inefficient for generating hydropower, and PacifiCorp knows a thing or two about efficiency. The Upper Klamath reservoirs were designed to maintain a near-constant level, with no ability to store excess water in one season for release at a later time.

These dams are what engineers call "run of river" facilities, designed to release essentially the same amount of water that flows into the reservoir. They can alter flows only very briefly — on a 24-hour cycle in the case of J.C. Boyle and Copco dams — storing up the river's flow overnight in order to release it in an oversized pulse the following day. This allows PacifiCorp to produce power when demand is highest in the middle of the day. But the dams simply cannot store enough water to reduce winter floods or release extra water in the summer.

Let's look at the numbers. Lost Creek can be raised and lowered by 121 feet every year, allowing it to store — or release — 315,000 acre-feet of water. That's enough to cover an area the size of Medford in 23 feet of water. Iron Gate Reservoir, the biggest of the four PacifiCorp reservoirs, can be raised or lowered by a mere 4 feet, allowing it to store only 3,790 acre-feet — enough to cover Medford in just over three inches of water. So although the Rogue and Klamath are similar sized rivers, Lost Creek can store 80 times as much water. Iron Gate can store just over a day's worth of the Klamath's average flow, while Lost Creek can store a whopping 84 days' worth of the Rogue's average. That's the difference between a single-purpose hydro dam like Iron Gate, and a multi-purpose dam like Lost Creek.

But these numbers are all theoretical anyway, because the PacifiCorp dams never have been, and never will be, operated for flood control or water storage. PacifiCorp isn't required to do those things and, given the dams' design, it couldn't if it wanted to. The only dam on the Klamath that provides flood control and water storage is Link River Dam, located far upstream at the outlet of Upper Klamath Lake. That dam is run by the U.S. Bureau of Reclamation — not PacifiCorp — and no one is suggesting that it be removed.

So let's be clear, and let's be fair: The only thing the PacifiCorp dams were designed to do is generate electricity, and that's all they will ever do.

What we should be debating, then, is whether the merits of power production outweigh the environmental costs of keeping these dams in place. That's a fair question to debate. The organization I represent, American Whitewater, believes the modest amount of electricity these dams produce (about 1/400th of California's total demand) pales when compared with the tremendous harm they cause by blocking migrating fish, brewing toxic algae and flooding or dewatering almost two dozen miles of one of the West's greatest recreational rivers.

Bill Cross is regional coordinator for American Whitewater. He teaches whitewater canoeing and rafting on the Klamath River.


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