Same Dam Story
Through May and June, as the late-spring melt flooded into Lake Powell, scientists, environmentalists and river runners all wondered aloud if the water level would reach the top of the Glen Canyon Dam spillway gates, which serve about the same purpose as the overflow drain on a bathroom sink.
Everyone but Bureau of Reclamation staffers was thinking back to 1983, when Reclamation had to open those gates to keep the lake from going over the top of the dam; the resultant flow broke through the spillway walls into the canyon sandstone, jeopardizing the dam and everything downstream.
This year Reclamation had gauged--or gambled--that the water would peak just four or five feet shy of the top, that it wouldn't even have to open the dam's "jet tubes," those big pipes in the spectacular TV footage of March 1996, when Interior Secretary Bruce Babbitt flipped a switch to start the controlled flood that "fixed" the Grand Canyon. Reclamation hates to open the tubes because they bypass the power-plant turbines, spilling water that otherwise might have generated electricity.
Babbitt's deluge last spring helped rebuild the eroded sand beaches of the canyon. Sediment that had come into the river from the streams and rivers that run into it was scoured up and redeposited on the sides of the canyon. It was a final experiment in a decade's worth of research that resulted in a new plan to run the Glen Canyon Dam, a plan that was supposed to be less damaging to the Grand Canyon.
However, because the lake is so high now, Reclamation will have to release heavier water flows than called for in the new plan all through the summer and again next spring to avoid catastrophe next year. The turbines will run at full throttle, generating watts and profits. The beaches will wash away.
And the scientists and environmentalists, dredging up years of experience and cynicism, assume that just as the Colorado River relentlessly flows and erodes the canyon, so does Reclamation's old way of doing business.
"The record of decision [which came out of the Environmental Impact Statement] that was signed into law basically said we will start to manage Lake Powell and Glen Canyon Dam differently to minimize the effect on the environmental resources downstream," says Dave Wegner, who headed Reclamation's research in the Grand Canyon until he was mysteriously transferred and subsequently quit at the end of last year ("Water Over the Dam," March 27). "But they followed the exact same mandates they have always followed, which is water and power come first. So the risk is still on the environmental resources."
Ironically, at a time when David Brower, the former Sierra Club archdruid, and Wegner, the Canyon's most experienced scientist, are calling to drain Lake Powell altogether, Reclamation has allowed it to fill to the brim.
When the Environmental Impact Statement was written in 1995, Lake Powell was so low that the document's authors at Reclamation speculated that it would take four or five years to "reach full elevation." That time cushion would allow the bureau to contemplate flood-control measures, such as raising the height of the spillway doors.
It took less than two years for the lake to fill.
"Right now they're pushing the levels at all of the dams," says Dave Hogan of the Southwest Center for Biological Diversity. "I think they'll wait until it's a crisis."
The Southwest Center filed suit against Reclamation in April over the levels of Lake Mead, just on the other side of the Grand Canyon from Lake Powell. The suit alleges that the high water was drowning habitat for the endangered Southwestern willow flycatcher.
Rob Smith of the Sierra Club, like Wegner, speculates that the high levels are "for the sake of the water and power interests, to make sure Lake Powell is as full as it can be."
Mark Manone, a geologist at Northern Arizona University who has researched the sediment levels in the Grand Canyon in the ongoing studies there, adds, "My personal opinion is, yes, absolutely, they keep it high just so they can go around [the rules]. It's one way for the dam to reclaim control."
But in reality, Reclamation doesn't need a full lake to generate electricity, nor a full basin to meet water demand.
"I would have thought they would have been more informed," Reclamation's Randy Peterson says of the Bureau's critics. "We don't have the option of releasing half the lake under current statutes. We can only release water in three situations: to avoid spills, to equalize water levels in Lake Mead, and to meet water demand."
The high levels, Peterson says, are the plain and simple result of high run-off years. And there have been worse years.
In June of 1983, Lake Powell rose to within four feet of the top of the spillway gates with plenty of water still raging into the lake from the Colorado River, and Reclamation opened the gates.
The spillways are long tunnels drilled through the sandstone canyon walls on either side of the dam. They were originally built to temporarily route the river around the dam construction site, then were kept as emergency drains. Four days after they were opened in 1983, dam workers saw giant chunks of concrete and stone flushing out the bottom of the spillway tunnels into the river, which meant that the rushing water had broken through the spillway walls and was washing away the rock at the base of the dam, threatening its very foundations. The spillway was shut, and after several shaky days, a crisis averted.
But in the aftermath, the lake levels were lowered as an antiflood contingency.
This year, with a snowpack as great as 1983's, Lake Powell rose 22 feet, to within five feet of the top of the spillways in the five weeks between May 22 and July 1. And while the flow into the lake is rapidly subsiding, a Bureau spokesman reasoned that it might go a foot higher, but that there was nothing to worry about because the Bureau had accurately predicted that the water would stop.
In fact, says Reclamation's Peterson, "It was just perfect. We put ourselves in a good position."
Nor would Reclamation admit that the lake is full. "I wouldn't consider five feet to full to be high," says Bureau spokesman Barry Wirth, raising a question as to what constitutes "high."
Reclamation officials expect that the Glen Canyon power plant will be running at near-full capacity for the rest of the summer because of the high lake level; it has run that way since January. When Babbitt signed the record of decision last fall, he commented that the dam would no longer be run like a toilet. In fact, it has been more like someone left the water running, and that has already taken its toll on the beaches that arose from last year's experimental flood.
According to Matt Kaplinski, a geologist at NAU, that flood had built beaches 176 percent larger than what existed immediately before the flood. By last September, they had shrunk to 97 percent larger, and since the water has run high, they are certainly lower still.
Kaplinski and other scientists worry that there is not yet enough sediment on the river bottom to redistribute, and, instead, the channel may be scoured clean if next winter is wet and Reclamation has to stage another spring flood to make room for water coming into Lake Powell.
Rob Smith of the Sierra Club says, "The great scientific advance we celebrated last year now has been undone by the old way of trying to store every last drop of water."
Meanwhile, Dave Wegner wonders if Reclamation and Mother Nature aren't setting up the same conditions that led to the 1983 flood.
"If you want to look at what the system is, we are analogous to 1982 right now. We've got all the reservoirs full, you've got El Nino already starting in Mexico," he says, referring to the Pacific Ocean current whose course often dictates whether a winter will be wet or dry. This fall and winter, according to El Nino, will be wet.
"This is exactly what happened in 1982," he continues. "We got the heavy rains in the fall of 1982, it saturated the soil, we got the heavy snowpack. So in the spring of '83: boom."
If there is a repeat of 1983, others in the environmental community theorize, the dam may come down and Lake Powell may drain itself.
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