BOB MELVILLE guides his raft down the Colorado River as it carves
its way toward the Grand Canyon. In the midst of an explanation of
the geology of the 300-million-year-old cliffs that shoot up from
the river, the 20-year veteran of rafting the canyon points to a
more recent development in the landscape.
"We've lost two-thirds of that beach," he says, nodding his
battered straw hat toward a steep, narrow ledge of sand on the
shore. "We used to play volleyball there; now we all huddle against
the cliff and there's barely enough room for a walkway."
Thirty miles upstream lies Glen Canyon Dam, which is widely
considered the cause of loss of beaches and fish habitat in the
Built and operated by the United States Bureau of Reclamation,
the 27-year-old dam created Lake Powell and provides water and
hydroelectric power for much of the West. It also traps sediment
that used to replenish beaches in the 292-mile stretch of river that
winds through the Glen Canyon Recreation Area and Grand Canyon
The water released from 200 feet below the surface of Lake Powell
emerges cold and clear, a far cry from the seasonally warm,
brick-colored water that gave the river its name: Colorado is
Spanish for "colored" or "reddish."
Some of the dam's effects are considered positive: The control of
seasonal floods has allowed the lavender-plumed tamarisk, willows,
and grasses to take root on the banks, which have become home to one
of the most diverse riverside bird populations in the Southwest.
Increasing numbers of trout nose through the cool, glassy pools and
currents of the river, attracting fishing enthusiasts as well as
migrating bald and golden eagles, who feed on spawning trout during
The water released from the bottom of Lake Powell is a shockingly
cold andidote to the desert heat. Many also enjoy its clarity: "I
wouldn't take a trip on a river if I knew it was going to be muddy,"
says a lawyer from Washington, D.C., as she makes camp on the river
bank after a day on Melville's raft.
But studies initiated by the Department of the Interior in 1982
found that the fluctuating level of the postcard-perfect, blue-green
water - which rises and falls as much as 13 feet daily with
electrical demand - can strand both fish and rafters and accelerates
the erosion of sand.
Particularly hard hit are native fish that proliferated in the
murky, seasonally warm Colorado before the dam. Two fish species
have disappeared from the stretch of river below Glen Canyon Dam and
above Lake Mead, downstream from the Grand Canyon. A third, the
endangered humpback chub, now has a stable population in only a few
miles of the river where its waters are warmed by tributaries.
"When it dawns on people that not just some company, but the
government of the United States, is knowingly destroying the
resource of the Grand Canyon by the way it runs the dam, people just
freak out," says Jim Ruch, the executive vice president of the Grand
Canyon Trust. The environmental group, based in Flagstaff, Ariz., is
one of many agitating for a change in the way the dam is operated.
In the face of public outcry and political pressure over the
degradation of the canyon, Secretary of the Interior Manuel Lujan
directed the Bureau of Reclamation to prepare an Environmental
Impact Statement (EIS) last July. Because the dam was constructed
before the National Environmental Policy Act was passed, no EIS was
done before it was built.
The EIS process - which includes dozens of scientific studies and
thousands of public comments - could lead to operational changes at
the dam or to other ways of protecting the downstream environment.
But conservation and recreation advocates, impatient with what
they consider the government's historic stalling on addressing the
environmental problems caused by the dam, are backing recently
introduced congressional legislation that calls for emergency
measures to protect the canyon. …