Case Study Suggests New Approach to Urban Water Supply

An MIT-based research team has evaluated potential problems regarding uncertain access to water in urban areas, and, based on a case study in Australia, suggested an alternate approach to water planning.

In a new paper, the researchers find there is often a strong case for building relatively modest, incremental additions to water infrastructure in advanced countries, rather than expensive larger-scale projects that may be needed only rarely.

Source: Pixabay

More specifically, the study looks at the city of Melbourne, where a 12-year drought from 1997 to 2009 led to construction of a $5 billion facility, the Victorian Desalination Plant. It was approved in 2007 and opened in 2012 — at a time when the drought had already receded. As a result, the plant has barely been used, and its inactivity, combined with its hefty price tag, has generated considerable controversy.

As an alternative, the study suggests, smaller, modular desalination plants could have met Melbourne’s needs at a lower price.

“If you build too much infrastructure, you’re building hundreds of millions or billions of dollars in assets you might not need,” says Sarah Fletcher, a PhD candidate in MIT’s Institute for Data, Systems, and Society (IDSS), who is the lead author of the new paper.

To be sure, Fletcher adds, “You don’t want to be in a situation where you have less water supply than you have demand.” As such, the study does not argue that a single solution applies to all cases, but presents a new method for pinpointing the best plan — and notes that in many cases, “moderate investment increases, together with flexible infrastructure design, can mitigate water-shortage risk significantly.”

The new paper, “Water Supply Infrastructure Planning: Decision-Making Framework to Classify Multiple Uncertainties and Evaluate Flexible Design,” was recently published online in the Journal of Water Resources Planning and Management, and will appear in the October 2017 print volume.

The co-authors are Fletcher, who is also affiliated with MIT’s Joint Program on the Science and Policy of Global Change; Marco Miotti, a PhD student in IDSS; Jaichander Swaminathan, a PhD student in MIT’s Department of Mechanical Engineering; Magdalena Klemun, a PhD student in IDSS; Kenneth Strzepek, a research scientist at the MIT Joint Program on the Science and Policy of Global Change and an emeritus professor of engineering at the University of Colorado; and Afreen Siddiqi, a research scientist in IDSS.

Siddiqi visited Melbourne during its historic drought and learned from local experts about the city’s challenging water-supply problem. The genesis of the current study comes from Siddiqi’s investigation into the Melbourne case and assessment that the complex problem of urban water security lies at the intersection of engineering design and strategic planning.   

The MIT team’s new framework for water-supply analysis incorporates several uncertainties that policymakers must confront in these cases, and runs large numbers of simulations of water availability over a 30-year period. It then presents planners with a decision tree about which infrastructure options are best calibrated to their needs.

The significant uncertainties include climate change and its effects on rainfall, as well as the impact of water shortages and population growth.

In studying the Melbourne case, the researchers looked at six infrastructure alternatives, including multiple types of desalination plants and a possible new pipeline to more-distant sources, and combinations of these things.

Read full article: MIT

Access document: ASCE Library

Media

Taxonomy

• Resource Management
• Technology
• Integrated Urban Water Management
• Sustainable Water Resource Management
• Natural Resource Management
• Urban Water
• Water Resource Management
• Urban Water Infrastructure
• Urban Design