Draft plan foresees a freer-flowing Colorado River
If a draft plan for
managing the massive Glen Canyon Dam in northern Arizona gains
final approval, the Colorado River could run through the Grand
Canyon much as it did before dam-builders arrived there in
The Glen Canyon draft EIS, released by the
Bureau of Reclamation Jan. 6, would protect the canyon from the
erratic flows that have characterized the last quarter
"Virtually every page
of this document represents a new way of thinking about water in
the West," says Tom Jensen, director of the Grand Canyon Trust.
"Commissioner Dan Beard and the Bureau of Reclamation have gone far
beyond the Bureau's traditional perspective which viewed Glen
Canyon Dam as just a tool to store water and generate power."
Former Secretary of the Interior Manuel Lujan
ordered the EIS in 1989, in response to complaints that changes in
water levels of up to 13 feet in one day swept away beaches and
artifacts, damaged native plants and fish, and short-changed Indian
reservations and other users downstream (HCN, 8/26/91).
In 1991, the Bureau of Reclamation issued
interim regulations to manage flows until the EIS was completed.
These cut the daily water fluctuations by 75 percent and kept dam
discharges between 5,000 and 20,000 cubic feet per second (cfs).
Legislators wrote these conservation measures into law in 1992 with
the Grand Canyon Protection Act (HCN, 11/2/93). Chief EIS scientist
Duncan Patten says that law "now puts the teeth into the draft EIS,
and guarantees the measures will be followed."
The draft EIS lists nine flow alternatives which will be open for
public comment through April 11. The Bureau's preferred
alternative, the "Modified Low Fluctuating Flow Alternative,"
advocates continuing the same flow levels set by the interim
regulations in 1991.
But the new plan also
includes important flow exceptions for research and power
production, and a new approach which the Bureau calls "adaptive
management." Duncan Patten, senior researcher for the EIS, says
"the draft EIS is unique because the flows aren't set in concrete."
Adaptive management could alter the EIS for endangered fish
research, beach habitat restoration and flood protection, he says.
This provision makes some environmentalists and power brokers
Power distributors worry about the
Bureau's plans to protect the endangered humpback chub and
razorback sucker. While biologists say the fish need steady flows
through the spring and summer for spawning, representatives from
the federal agency that markets hydropower, the Western Area Power
Administration, aren't convinced. WAPA engineer Ron Moulton says
the benefits of the steady flows may only be minor. Instead of
steady flows, he suggests gradually modifying interim flows to
protect the fish.
Almost one-third of the dam's
1350 megawatt capacity cannot be used under steady flows, says
Jerry Demel, a manager for Denver's Tristate Electric Association.
Demel says the limitations would force WAPA to purchase surplus
energy from coal-burning plants and other dams during peak energy
demand. The switch could cost the average household an additional
$180 per year, and would also hurt small businesses and irrigators,
In another conservation measure, the
draft EIS suggests allowing 40,000 cfs releases about once every
decade to mimic flash floods. Scientists hope the floodwaters would
deposit sand and nutrients high above the typical water level,
restoring sediments lost to gradual erosion.
The plan would also allow exceptions for power producers. In the
preferred alternative, WAPA can still violate dam restrictions
about 20 hours per month to respond to sudden demands for power.
The 1991 interim guidelines allowed for this exception as well, but
WAPA has seldom used it, according to Patten.
Some environmentalists worry that such flexibility might lead to
abuse. American Rivers vice president Dale Pontius says his group
wants to make sure the final EIS does not allow any changes in dam
operations that would compromise the management of the Colorado
River as a dynamic natural system.
Bryan Foster, HCN