From 1997 to 2009, Melbourne, Australia experienced what was ultimately called the Millennium Drought, the worst drought on record in the island continent. To compensate, the city’s water planners invested about $3 billion in 2007 in a 150-million-cubic-meter (MCM)/year reverse osmosis desalination plant. At the time, the plant was one of the largest of its kind in the world. As it turned out, the drought ended in 2009 before the plant was completed in 2012, and it lay idle for the next five years. Could the plant have been designed differently so that far fewer assets were put at risk of ending up stranded?
Sarah Fletcher thinks so. A PhD candidate in Engineering Systems and National Science Foundation (NSF) Graduate Research Fellow who is affiliated with the MIT Joint Program on the Science and Policy of Global Change, Fletcher has studied the potential for a flexible desalination design, in which the plant is sized so that it can hold the full 150 MCM/year of capacity but only half the capacity is built initially, with the remainder added over time, as necessary, in response to demand growth. According to her calculations, this flexible approach can achieve a similar level of water reliability at a reduced cost of potentially $1 billion.
When Fletcher presented her findings (entitled “Flexible water supply planning under multiple uncertainties: A differentiated approach”) at the Technology Management and Policy Graduate Consortium in June in Stony Brook, New York, she received the Consortium’s “Best Presentation” award. At the start of each summer since 2002, the Consortium has brought together faculty and advanced students from several graduate programs focused on technology, management and public policy, including institutions based in the U.S., Canada, England, the Netherlands and Portugal. Fletcher’s research on the Melbourne desalination plant design will soon be featured in a paper in the Journal of Water Resources Planning and Management.
Also in June, Fletcher received one of two 2017-2018 Rasikbhai L. Meswani Fellowships for Water Solutions, a new Abdul Latif Jameel World Water and Food Security Lab (J-WAFS) Fellowship for Water Solutions for outstanding PhD students pursuing solutions to pressing global water-supply challenges.
The Meswani Fellowship recognizes her broader efforts to develop a framework for (1) modeling and managing the uncertainties that water-supply planners face (including inconsistent rainfall and runoff levels, population growth and climate change impacts) and the priorities of key stakeholders (e.g. reliability of service, cost and environmental protection); and (2) evaluating the potential for the design of proactive, flexible engineering infrastructure and policy to minimize the risk from uncertainties. Fletcher is applying this framework to water-supply planning challenges in Australia, Kenya and Saudi Arabia.
“I think what's impactful about this work is that is brings together many facets of the water-supply planning challenge in a single, systems-level analysis to help policymakers and planners make real-world decisions,” says Fletcher, whose research integrates hydrological models, decision models and uncertainty analysis with flexible engineering design to provide analysis to support water-supply decision-making.
”Sarah has the unique ability to bring cutting-edge research on flexible design and decision-making under uncertainty to the critical area of water resources infrastructure investment,” says Kenneth Strzepek, a research scientist at the Joint Program who supervises Fletcher’s research under funding from the NSF and the Center for Complex Engineering Systems, a joint MIT–KACST* (Riyadh, Saudi Arabia) research center. “Her work is allowing planners to achieve significant cost savings while providing an improved level of service.”
*KACST – King Abdullah City for Science and Technology
Photo: Joint Program-affiliated PhD student Sarah Fletcher (MIT Engineering Systems) (right) with (from left) Abby Onencan (Delft University of Technology), Joint Program research assistant Kathleen Mulvaney (MIT Technology and Policy Program), Kunbi Adetona (University of Calgary) and Anjuli Jain Figueroa (MIT Department of Civil and Environmental Engineering), at the Technology Management and Policy Graduate Consortium in June in Stony Brook, New York (Photo courtesy of Sarah Fletcher)