As a media event, the Grand Canyon spring flood of
“96 was a roaring success. On cue from the Today Show, Interior
Secretary Bruce Babbitt turned a wheel, pushed a button, pulled a
lever and opened the first of four jet tubes to send Lake Powell
water downstream into the Grand Canyon.
Whether
the flood will live up to its billing as a grand realignment of
America’s way of dealing with the downstream effects of dams is
another matter. Scientists, politicians and interest groups will be
debating that for months after the scientific data are
in.
Still, on March 26 and throughout the next
week, the Bureau of Reclamation committed what agency veterans
might consider blasphemy: It opened the valves and spilled stored
water from Lake Powell, bypassing the turbines which make Glen
Canyon Dam a virtual cash register. It created the very kind of
flood dams are built to prevent.
The purpose was
two-fold: to restore the Grand Canyon’s disappearing beaches, and
to scour out backwater areas critical to wildlife habitat,
especially that of the all but extinct humpback
chub.
“I was up here when this dam was built in
the “50s, and at the time it didn’t occur to anybody the relation
between the dam and what would happen downstream,” Babbitt recalled
during a pre-flood float trip with reporters through what remains
of Glen Canyon downstream from the dam. “Now what we’re doing is
understanding everything relates, and if we’re going to find
equilibrium on this landscape we’re going to have to see the entire
watershed as a unit and manage it as an ecosystem.”
The ecosystem has been out of whack for 30 years
now. The dam environmentalists love to hate traps 90 percent of the
Colorado River’s sediment flow in Lake Powell. The river, which
used to run warm and muddy, now runs clear and cold. And
gully-washing spring floods have been replaced by controlled flows
timed only to meet power needs in Sunbelt meccas such as Phoenix,
Las Vegas and Los Angeles.
“What’s happened is
the dam converted one of our pristine national treasures into a
flush toilet,” says Larry Lake, whose Western River Expeditions is
the largest boat-trip operator through the Grand
Canyon.
Over the past 10 years, river guides have
been shocked by the rapid erosion and disappearance of beaches.
Downstream flows have eroded what beaches existed, and with only
clear water running downstream, they haven’t been able to rebuild.
The idea of the intentional flood was to stir sand lying in the
Colorado River channel, suspend it in the rising water, and let it
settle out as the water was slowly drawn back
down.
Some river guides were skeptical, but most
applauded any effort to rebuild beaches. “Within four or five years
it’s conceivable we’re going to have a very difficult time
providing river trips,” Lake says.
With all four
jet tubes open, the great flood of “96 measured 45,000 cubic feet
per second. That’s a huge increase from normal power operations
which usually top out at 12,000 cfs, but it’s still sparse compared
to the pre-dam gully-washers which could hit 200,000-300,000 cfs
for weeks at a time.
“It’s a trickle compared to
what Mother Nature could provide,” Reclamation scientist Dave
Wegner says. “But to the Grand Canyon, it’s essential that we find
a better way to operate the dam.”
More than 150
scientists floated downstream ahead of the flood to set up
monitoring equipment, including a real-time connection to the
Internet to provide a play-by-play for scientists worldwide. Many
of the principles learned from this flood experiment could apply
elsewhere. Babbitt wonders, for instance, if Pacific Northwest
salmon streams could benefit from intentional
floods.
There may be other, unintended, side
effects. Fishing guides and scientists are concerned the trout
fishery which has blossomed just below the dam (due to the clear,
cold water which has extirpated most native fish) may be wiped
out.
“High flows may push the trout out of the
fishing area,” said Wegner, adding that the insects the trout eat
could be disrupted as well. And one Park Service official who did
not want to be quoted by name admitted the first few miles below
the dam won’t see the benefits of flooding, but instead will become
a “sacrifice area.”
But, the river runners who
love to berate Glen Canyon Dam were lined up along the shore at
Lee’s Ferry, waiting for the flood flow to hit. It’s not often
these days when true high water comes roaring down the
Colorado.
For more information contact: Dave
Wegner, Glen Canyon Environmental Studies, P.O. Box 22459,
Flagstaff, AZ 86002 (520/556-7363).
– Larry
Warren
Larry Warren is reports
on the environment for KUTV News in Salt Lake City,
Utah.
This article appeared in the print edition of the magazine with the headline Stirring things up on the Colorado River.
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