Decision making and Climate Change

The two primary objectives of the proposed study are: 1) To evaluate the likely effects (costs and benefits) of climate change, together with all other important existing and interacting stressors, on the services provided by aquatic ecological systems in an entire watershed, and, 2) To develop and investigative, methodological framework that can be applied to similar basins elsewhere.

Despite their great value, the human record of stewardship of freshwater ecosystem goods and services has been poor. Largely out of a lack of understanding or ignoring their real value, we have often destroyed or impaired the ability of ecosystems to provide important services. In many areas, we find ourselves turning back the clock to restore (e.g., reforestation, wetland restoration, invasive species elimination, wildlife habitat restoration, and dam removal), often at great cost and with limited success, services that previously were freely available (Mooney and Hobbs, 2000; NRC, 1992; Strange et al., 2002).

In heavily developed water systems such as the San Francisco Bay Watershed, water management decision-making processes require tools that can characterize potential tradeoffs between water management objectives in the face of climate change and other stressors. To account for this potentially competitive interaction, an integrated water resource Decision Support System (DSS) must balance water supplies generated through watershed scale hydrologic processes, multiple water demands, and environmental requirements characterized by spatially and temporally variable allocation priorities and supply preferences.

The Water Evaluation and Planning (WEAP) model accommodates these requirements because it can evaluate the hydrologic feasibility of water management options related to the storage, distribution, use, and conservation of regional water supplies (Sieber et al. 2004; Yates et al. 2004). The model can explicitly incorporate climatic change and changes in land use and other watershed conditions that control watershed response. Simultaneously, it can address opportunities for expanding the beneficial uses of regional water supplies to better satisfy an array of possible water management objectives.

Examples of management opportunities include the re-operation of existing water supply infrastructure, new agricultural policies and practices, the construction of new facilities, investments in demand management initiatives, changes in allocation priorities and supply preferences, watershed improvement efforts, and changes in regulations regarding the management and allocation of available water supply.

Uncertainty related to each of these changes, in both the physical and management systems, can be addressed through the internal organization and evaluation of multiple scenarios. As part of a four-year study on freshwater ecosystem services, the assembled study team (ST) has worked throughout the Sacramento River basin of the San Francisco Bay Watershed (SFBW), applying the WEAP model to investigate the potential impacts of climate change on various freshwater ecosystem services. This is a tool that is ready to contribute to the characterization of the water management tradeoffs in the face of climate change in a number of decision-making settings in California

SEI's task
SEI will inventory water management decisions in California, and selected four case studies to provide climate change information for improved decision making. Once our case-studies are defined, we will organize (an) invitation workshop(s) of relevant stakeholders associated with each case study.

For the study team, these workshops are meant to serve three general purposes:

1) Introduce the study team and our methods and approaches to garner credibility.

2) Illustrate that the selected case studies and their associated climate dependent decisions are relevant

3) Establish legitimacy by ensuring that the study team has engaged the correct decision makers.

In addition, the workshop(s) would seek input from participants in defining how climate change information could be used to set and attain targeted outcomes in their particular processes. We would solicit input on how DSS tools such as WEAP could be used or improved to attain desired outcomes. From the workshop(s), the study team would appropriately react to the suggestions of this stakeholder dialogue and implement those recommendations into the project tools (e.g. reconfiguration of model schematic, refinement of model to reflect important components, additional climate change scenarios, etc.).

The refined project tools would then be used to carry-out the analysis based on the detailed work plans. As we engage the analytical process of each case study, we envision on ongoing dialogue between the study team, and the decision making personnel of each case study. We will summarize the experiences in a final report, and also submit articles to peer-reviewed journals for broad dissemination.

Partners: National Center for Atmospheric Research

Funder: U.S. Environmental Protection Agency