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Two Deltas, Two Views of Adaptive Management

April 2014

Approaches to adaptive management are not all the same. Tjalling Vlieg, a visiting Dutch student who worked in the Council’s Science Program in 2011/2012 recently had an article published in a Dutch policy journal based on his research comparing adaptive management in the Rhine-Meuse Estuary in the Netherlands and the Sacramento-San Joaquin Bay-Delta.

In his paper, “Reactive versus anticipative adaptive management of Deltas” coauthored by Mark Zandvort and published in the Journal of Water Governance he concludes that the Dutch approach is more “anticipative” of future conditions while the Bay-Delta exemplifies a more “reactive” adaptive management approach and that a blend of the two approaches would be best for the future.

Californian Adaptive Management (AM) is primarily applied to ecosystem management while Dutch Adaptive Delta Management (ADM) is primarily developed for flood risk management and fresh water supply purposes, Vlieg explains.

Californian AM is based on modeling the performance of different actions. “It emphasizes that once management actions are selected, formal and continuous learning is required to deal with uncertain effects and effectiveness of management actions,” Vlieg says in the paper. “Thus it reacts on present states in a continuous fashion as adequately and flexibly as possible.”

In contrast, Dutch ADM anticipates possible futures through projections of climate change and socioeconomic circumstances. Different sets of measures to avoid or postpone projected problems are developed in advance. “In ADM, uncertainty in projections is recognized and possible rejection of projections over time is acknowledged,” the paper states. “For climatic and socio-economic circumstances ADM aims to ensure that alternative adaptation pathways can still be opted.”

“The anticipative application of adaptive management in Holland is a useful insight for the California system,” said Chris Enright of the Delta Science Program who served as Vlieg’s mentor when he was in California. “Even though we plan to change the Delta on purpose to improve ecosystem services and we know climate change is happening, we have few systems in place to test alternative outcomes at the landscape scale. We risk unintended consequences unless we anticipate and adapt to change better.”

Vlieg and Zandvoort argue that good Delta management should be based on long term projections, as in Dutch ADM, and scientific learning from implemented actions, as in Californian AM. “A hybrid of both concepts can thus be created in order to strengthen adaptive management practice in the face of future uncertainty.”

The duo distilled four lessons from their comparison:

  • The Dutch ADM guideline does not elaborate on how or what to monitor to assess adaptation tipping points. Possibly this makes ADM in its management scheme not as anticipative as it claims to be. Comparing it to Californian AM reveals that a good monitoring plan could enhance the claim that it anticipates changing system circumstances.
  • To fit the purpose of ecosystem management, Dutch ADM should incorporate scientific learning by monitoring the effects and effectiveness of management actions. Dutch Delta planners could learn from the Sacramento-San Joaquin Delta case, which forms a good example of continuous scientific learning.
  • The scope of Californian AM has expanded to include consideration of socioeconomic effects and climate change adaptation. Californian AM could leverage its strengths in monitoring and learning to more proactively anticipate the likely effects of future flood emergencies, species invasions, and restoration of ecosystem services for society. For now, Californian AM does not prescribe how these probable futures should be responded to.
  • Californian AM could learn from Dutch AM by pursuing multi-purpose projects where investments and efforts complement each other.

The paper concludes that good Delta management should be based on both long-term projections, as in Dutch ADM, and scientific learning from implemented actions, as in Californian AM. The paper concludes: “In the end concepts like Adaptive Management are never finished, if only because the situations they are developed for continuously change.”

“Tjalling's master thesis research and the scientific article he wrote with Mark Zandvoort show that modern-day Delta management requires adequate anticipation and reaction to deal with unpredictable ecosystem relationships, climate change impacts and socio-economic changes,” said Peter Wijsman of ARCADIS. “In his work, Tjalling established a very valuable knowledge bridge on adaptive management between the Delta Stewardship Council and the Dutch Delta Program. We are proud to have provided support to him for this important research.”

Coequal goals

The Delta Stewardship Council was created in legislation to achieve the state mandated coequal goals for the Delta. "'Coequal goals' means the two goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem. The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." (CA Water Code §85054)