Upmanu Lall, professor of engineering at Columbia University, explores the future of irrigation.
Upmanu Lall is director of the Columbia Water Center ,and the Alan and Carol Silberstein Professor of Engineering at Columbia University. He has broad interests in hydrology, climate dynamics, water resource systems analysis, risk management and sustainability. He is motivated by challenging questions at the intersection of these fields, especially where they have relevance to societal outcomes or to the advancement of science towards innovative application. He has been engaged in high-level public and scientific discussion through the media, the World Economic Forum, and with governments, foundations, development banks, and corporations. He has served on several national and international panels. He was one of the originators of the Consortium of Universities for the Advancement of Hydrologic Science, and is currently the President-Elect of the Natural Hazards Focus Group of the American Geophysical Union.
In the future, due to population growth and climate shifts, the world will run short of fresh water; in fact it is already happening in many places. Even wealthy countries like the United States face huge challenges, with decaying infrastructure that will cost trillions to replace. That is, unless we find ways to do things differently.
My colleagues and I are looking at how to adapt, using emerging disruptive technologies, combined with new business models, careful design and policy changes. In the twenty-first century, more and more people are moving to cities; but those cities still rely on twentieth, or even nineteenth-century technology.. Cities like New York get their water from distant rural places through aging pipes, and produce a huge amount of wastewater. The use of old sewer infrastructure means that during rainstorms, sewers overflow and empty into open waterways.
But what if instead of collecting water from far-off areas, we captured storm water locally and stored it, instead of sending it into the sewers? Imagine if we designed such systems at the neighborhood scale, or for individual buildings? Imagine further if we treated and reused that water at different levels for different purposes.
Emerging technologies can help us do this. These include graphene and carbon nanotube filters, which can treat wastewater to an impeccable degree, using a tiny fraction of the energy that current filtering systems use. Combining these technologies with remote water quality sensors would allow us to create a system that would yield us more water, and save money and energy.
This doesn’t mean that the centralized systems as they exist today would go away. We’ll still have drinking water piped long distances; we’ll still have sewers; and we’ll still have big wastewater treatment plants. But our reliance on old-fashioned water technology could be reduced dramatically, and we’ll still have all the water we need.