Water Resources Planning Under Uncertainty

NOLA canal, photo courtesy of wikimediacommons

Water resource managers have significant experience successfully planning and operating their systems in the face of uncertainty regarding future hydrology, weather, available water supply, and projected water demand. In recent years, however, it has become clear that today's planning approaches may no longer be adequate. Dynamic population and economic growth have placed increasing pressure on water supplies and concerns about environmental impacts have grown.

In addition, the potential for climate change has confronted water managers with an additional novel challenge. While in any particular service area the precise impacts of climate change for temperature, precipitation, evaporation, storm water capture, and imported supplies remain deeply uncertain, it has become increasingly clear that past weather and hydrological records no longer provide an accurate guide to future weather and hydrology.

To help water managers address these novel challenges, our research develops and applies new quantitative methods and tools to support decisions under conditions of deep uncertainty. We have helped a variety of water management jurisdictions use scenarios and other approaches to characterize their most important uncertainties and to identify robust options for meeting their goals over a wide range of plausible climate-change futures.

Major Activities and Publications

Development of New Methodologies for Assisting in Water Planning Under Deep Uncertainty (2005 Present)

The RAND team has worked to generalize Robust Decisionmaking (RDM) methodologies to be used by water resource managers. RDM is a new quantitative approach for identifying strategies that perform reasonably well compared to the alternatives across a very wide range of plausible futures. RDM characterizes uncertainty, and the tradeoffs among alternative policy choices, in ways that decision makers find credible and can contribute usefully to contentious debates such as those surrounding water planning.

Identifying Robust Water Management Strategies for the Inland Empire Utilities Agency (2006 – Present)

The RAND team partnered with the Inland Empire Utilities Agency (IEUA) to develop new planning tools and data to evaluate the performance of their current plans. We then presented the information in various ways over the course of four workshops (three in the fall of 2006 and one in the fall of 2007). We surveyed participants before and after each workshop to try to better understand how the information influenced the participants' view of the seriousness of climate change to their region and the ability for the region to respond meaningfully to the threat. Over the course of the workshops, over 50 elected officials and staff from cities and state, regional, and local water agencies participated in this study.

Water Scenario Workshops in Southern California (2005)

RAND partnered with UC Santa Barbara researchers to develop a simple scenario model of Southern California water supply and demand to evaluate the potential for local resource development to accommodate future growth and water management uncertainty. We held three workshops in Southern California in the fall of 2005 to discuss local water resource potential facilitated by the developed scenario model.

State Water Demand Scenarios for California Department of Water Resources Water Plan Update 2005 (2004-2005)

We worked with the California Department of Water Resources to develop a simple model of California water demand. We developed a water demand scenario tool to explore robust water management strategies in California. This tool was subsequently used by DWR to quantify three narrative scenarios of water demand for the California Water Plan Update 2005.