Decision support experiments and evaluations using seasonal to ...

tion patterns. There are concerns that multiple
islands would be inundated in a “10-year storm
event”, which represents extreme local vulnerability
to flooding.
In the central delta, there are five county governments
in addition to multiple federal and
state agencies and non-governmental organizations
whose perspectives need to be integrated
into the management process, which is one of
the purposes of the CALFED program. A key
decision being faced is whether delta interests
should invest in trying to build up and repair
levies to protect subsided soils. What are the
implications for other islands when one island
floods? Knowing the likelihood of sea-level
rise of various magnitudes will significantly
constrain the answers to these questions. For
example, if the rise is greater than one foot
in the next 50 to 100 years, that could end the
debate about whether to use levee improvements
to further protect these islands. Smaller
amounts of sea-level rise will make this decision
less clear-cut. Answers are needed in order to
support decisions about the delta in the near
term.
Implementation/Application
Hundreds of millions of dollars of restoration
work has been done in the delta and associated
watersheds, and more investment is required.
Where should money be invested for effective
long-term impact? There is a need to invest in
restoring lands at intertidal and higher elevations
so that wetlands can evolve uphill while
tracking rising sea level (estuarine progression).
Protecting only “critical” delta islands (those
with major existing infrastructure) to endure a
100-year flood will cost around $2.6 billion.
Another way that climate change-related information
is critical to delta management is in
estimating volumes and timing of runoff from
the Sierra Nevada mountain range (Knowles
et al., 2006). To the extent that snowpack will
be diminished and snowmelt runoff occurs
earlier, there are implications for flood control,
water supply and conveyance, and seawater
intrusion—all of which affect habitat and land
use decisions. One possible approach to water
shortages is more recent aggressive management
of reservoirs to maximize water supply
benefits, thereby possibly increasing flood
Decision-Support Experiments and Evaluations using Seasonal to
Interannual Forecasts and Observational Data: A Focus on Water Resources
risk. The State Water Project is now looking at
a ten percent failure rate operating guideline
at Oroville rather than a 5 percent failure rate
operating guideline; this would provide much
more water supply flexibility.
Lessons Learned
Until recently the implications of climate change
and sea-level rise were not considered in the
context of solutions to the Bay Delta problem—
particularly in the context of climate variability.
These implications are currently considered to
be critical factors in infrastructure planning,
and the time horizon for future planning has
been extended to to over 100 years (Delta Vision
Blue Ribbon Task Force, 2008). The relatively
rapid shift in perception of the urgency
of climate change impacts was not predicted,
but does demand renewed consideration of
adaptive management strategies in the context
of incremental changes in understanding (as
opposed to gradual increases in accumulation
of new facts, which is the dominant paradigm
in adaptive management).
4.2.2 Organizational and
Institutional Dimensions of
Decision-Support Experiments
These seven experiments illuminate the need
for effective two-way communication among
tool developers and users, and the importance
of organizational culture in fostering collaboration.
An especially important lesson they
afford is in underscoring the significance of
boundary-spanning entities to enable decisionsupport
transformation. Boundary spanning,
discussed in Section 4.3, refers to the activities
of special scientific/stakeholder committees,
agency coordinating bodies, or task forces that
facilitate bringing together tool developers and
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