Researchers examine the response to a lengthy drought in Melbourne, Australia, to develop an approach for building new water supply infrastructure that won’t break the bank
Small additions to water supply infrastructure rather than expensive, large-scale projects. That’s the better approach for combatting problems like drought, according to an MIT-based research team.
The team focused on the city of Melbourne, Australia, for its recently released paper, “Water Supply Infrastructure Planning: Decision-Making Framework to Classify Multiple Uncertainties and Evaluate Flexible Design.” It looked at Melbourne’s lengthy drought from 1997 to 2009, which led to the construction of a $5 billion desalination plant. Approved in 2007, the plant went online in 2012. But since the drought had ended by then, the plant’s use has not lined up with its hefty price tag. The MIT study suggests that an approach of smaller, modular desalination plants could have still met Melbourne’s needs, and at a much lower price.
The research team ran 100,000 simulations of 30-year conditions in Melbourne and found that in 80 percent of all years, there wouldn’t be a water shortage at all, though in the years where drought conditions existed, the water shortage would be significant. When factoring costs into the analysis, that meant that building no new infrastructure was the best option about half of the time. But doing nothing was also the worst-performing option about 30 percent of the time, which is why adding more modest, less expensive pieces of infrastructure can be a good approach, the researchers claim.
The desalination plant that was ultimately built in Melbourne can produce 150 million cubic meters of water per year. According to the MIT team’s simulations, building a plant half that size was one of the top three options 90 percent of the time, and was never the worst-performing option. The team looked at six different infrastructure alternatives, including multiple types of desalination plants, a new pipeline to more-distant water sources, and combinations of the options.
“We’re used to building large-scale desalination plants, and there’s less history of building more modular plants,” lead author Sarah Fletcher says, noting that building smaller provides the ability to bring the plant online more quickly and then scale up if necessary.
“You only build a certain number of modules in the beginning, and you can add a certain number later,” she says. “That’s different than building a small plant and then another small plant. You’re being proactive and planning to adapt in the future.”
According to the researchers, the exact results of the study would vary from region to region, depending on the climate and population factors that affect water supply, but the general idea of taking a more modest approach in building out water supply infrastructure would likely be a sound solution in many situations.
“If you build too much infrastructure, you’re building hundreds of millions or billions of dollars in assets you might not need,” says Fletcher.