Decision support experiments and evaluations using seasonal to ...

The U.S. Climate Change Science Program
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replaced by daily fluctuations by as much as
15 feet. A band of exotic vegetation colonized
a river corridor no longer scoured by spring
floods; five of eight native fish species disappeared;
and the broad sand beaches of the
pre-dam river eroded away. Utilities and cities
within the region came to rely on the dam’s low
cost power and water, and in-stream values were
ignored (Carothers and Brown, 1991).
Attempts to abate or even reverse these impacts
came about in two ways. First, in 1992, under
pressure from environmental organizations,
Congress passed the Grand Canyon Protection
Act that mandated Glen Canyon Dam’s
operations coincide with protection, migration,
and improvement of the natural and cultural
resources of the Colorado River. Second, in
1996, the Bureau of Reclamation undertook
an experimental flood to restore disturbance
and dynamics to the river ecosystem. Planners
hoped that additional sand would be deposited
on canyon beaches and that backwaters (important
rearing areas for native fish) would
be revitalized. They also hoped the new sand
deposits would stabilize eroding cultural sites
while high flows would flush some exotic
fish species out of the system (Moody, 1997;
Restoring the Waters, 1997). The 1996 flood
created over 50 new sandbars, enhanced existing
ones, stabilized cultural sites, and helped to
restore some downstream sport fisheries. What
made these changes possible was a consensus
developed through a six-year process led by the
Bureau that brought together diverse stakeholders
on a regular basis. This process developed a
new operational plan for Lake Powell, produced
an environmental impact statement for the
project, and compelled the Bureau (working
with the National Park Service) to implement
an adaptive management approach that encouraged
wide discussion over all management
decisions.
While some environmental restoration has occurred,
improvement to backwaters has been
less successful. Despite efforts to restore native
fisheries, the long-term impact of exotic fish
populations on the native biological community,
as well as potential for long-term recovery of
native species, remains uncertain (Restoring the
Waters, 1997). The relevance for climate variability
decision support in the Glen Canyon case
is that continued drought in the Southwest is
placing increasing stress on the land and water
resources of the region, including agriculture
lands. Efforts to restore the river to conditions
more nearly approximating the era before the
dam was built will require changes in the dam’s
operating regime that will force a greater balance
between instream flow considerations and
power generation and offstream water supply.
This will also require imaginative uses of forecast
information to ensure that these various
needs can be optimized.
4.3.9 Measurable Indicators
of Progress to Promote
Information Access and Use
These cases, and our previous discussion about
capacity building, point to four basic measures
that can be used to evaluate progress in providing
equitable access to decision-supportgenerated
information. First, the overall process
of tool development should be inclusive.
This could be measured and documented over
Chapter 4