While some uncertainties can be addressed through field studies and other research, some will remain, at least within the timeframe of the assessment, irreducible. Some of these will be more important than others and in some cases, can affect the ability to make informed and accepted decisions. Both the selection of preferred alternatives and the ability to garner support for them will increasingly depend on an honest exploration of uncertainty and a formal commitment to learning over time.

This means that the post-implementation management regime will increasingly rely on an adaptive approach that could include both passive monitoring of performance, and active experimentation (e.g., a sequence of time-limited experimental flow releases accompanied by extensive monitoring) to discriminate among competing hypotheses and reduce uncertainty more rapidly than would otherwise occur (Walters, 1986). It will also increasingly call for the establishment of institutions (e.g., multi-party monitoring committees) that can respond to new information.

Uncertainties are not limited to scientific or impact-related elements of the decision. Over time, conditions will change and new information will emerge. New information may be related to the facts-basis for decisions (e.g., about technological, market, environmental social and hydrological conditions) or to changing values (e.g., changes in relative priorities across water uses, especially as development needs change). Changes in technology, markets and hydrology are generally mainstreamed into management of dams and hydro facilities. Changes in environmental and social conditions, and relative values amongst water uses, are less closely attended.

A good process will involve building relationships, developing analytical tools, and establishing institutional arrangements (e.g., review processes) and cooperative management agreements that both reduce uncertainty and respond to new information over time.

The last step in the decision process then is to identify mechanisms for on-going monitoring to ensure accountability with respect to on-ground results, research to improve the information base for future decisions, and a review mechanism so that new information can be incorporated into future decisions. A decision process that is serious about sustainability is one that will create a legacy of learning and adaptation, leading to greater capacity – in terms of technical information, human resources and institutional capacity – to make better decisions in the future. A key challenge will be to both reduce critical uncertainties and build in institutional flexibility to respond to new information without overextending management and political resources.

Key Ideas

• As decisions are implemented, some of the uncertainties inherent in the analysis will be resolved
• Because of this, it is important to continually assess the outcome of the decision (if possible) to ensure things are unfolding as desired
• It is possible to plan for this by identifying ahead of time which elements will need ongoing monitoring, and what conditions might trigger a review of the decision cycle