MIT’s Case study suggests new approach to urban water supply

Researchers have found 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.

If you live in the developed world, safe water is usually just a faucet-turn away. And yet, global warming, drought conditions, and population growth in coming decades could change that, ushering in an era of uncertain access to water.

Now an MIT-based research team has evaluated those potential problems 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.

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.

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.

News Source: http://news.mit.edu/2017/drought-remedy-keep-infrastructure-fast-cheap-under-control-0814