Three big trends are coming, said Ken Conca, Professor at American University’s School for International Service at a recent Wilson Center event that explored the future of water. “We’ll be storing a lot more water,” he said. “We’ll be recycling a lot more water. And we’ll be thinking much more systematically and foundationally about flood risk.”

To meet the water challenges of the next 30 to 50 years, water storage will become increasingly important to smooth out extremes, to buffer against shortages, and to replace natural storage that we’re losing as snowpack and ice melt begin to vanish in a greenhouse world, he said. Water recycling will become a tool to enhance the water supply and reduce the energy and conservation costs of our current inefficient water system.

Inefficient Use of Water

For example, Conca said that we clean water to world class drinking standards and use a large amount of energy to pump it to your toilet. If your toilet is more than 20 years old, with two flushes of that to make a few ounces of urine go away, you have just flushed away what the World Health Organization says is the daily survivable minimum of water for immediate personal use. “That is not a smart system, and that is going to start to change,” he added.

Conca also predicted that more attention will go to combatting flood risk, particularly the “double-exposure” that coastal communities face. On the one hand, they’re exposed not only to intensifying storms from the sea and higher sea levels. On the other, they are vulnerable to the danger of flash flooding from heavy rains, like those from Hurricane Harvey that stalled over and inundated Houston.

 While climate change is obviously one of the drivers behind these adaptation trends, it isn’t the only one, he said. Other drivers include the shifting dynamics of water economics and a variety of new actors, such as the Department of Defense, which are taking actions to manage their exposure to risk and making much needed updates to existing water infrastructure. “That’s one of the really key points,” he said. “We have to get the infrastructure decisions right.” Longevity poses a planning challenge, given that new water infrastructure may need to survive more than a hundred years.

Unintended Consequences

Unintended social and ecological consequences of infrastructure decisions could also have a large effect on “the peace and conflict dimensions that we will have to pay attention to as well,” he said. Disputes may arise when big dam projects do not consider environmental or human rights consequences, when livelihoods and profits are altered by the use of recycled water, and when flood protection affects property values and the way of life in historic neighborhoods and communities.

While in aggregate, the big trends may look like positive adaptations that will increase resilience and further risk management, Conca pointed to a downside. They are laden with tremendous potential for injustice, for inequality, for contentiousness, and for conflict, violent or otherwise. “I’d like to stress that it’s not enough to capture the macro-benefits to society of these broad adjustments that we know are coming and that we know make sense writ large,” he said. “We have to manage the micro-considerations. Who wins? Who loses? Whose voice? How do we spot the unintended consequences? How do we spot the second-order effects?”

Water Project Micro-effects

For many people, the second-order and unintended effects are the real story, Conca says. “As we get climate smart, we also have to get conflict smart and equity smart.” To do so competitively, we must put more time into decision-making and consider the micro-effects of water infrastructure projects. If these effects are over-looked, production based on the principles of economies of scale appears to be the most cost effective strategy in designing water infrastructure.

For example, building one big pile of concrete and generating 1,000 megawatts in one project is much more efficient than 10 projects generating 100 megawatts each or 1,000 projects that produce one megawatt each. However, with factors such as changing land and water prices, updated environmental regulations, and a variety of social considerations, economies of scale eventually may turn into “diseconomies” of scale.

Economies of Flexibility

“We don’t know what the future is going to entail,” Conca said. “There is a value that we can price in delaying a decision until you have more information,” he said, and in the ability to change your mind. These advantages form a cost efficient “economy of flexibility” by adapting and adjusting water infrastructure decisions to a variety of ever-changing challenges. These “economies of flexibility” eventually outweigh economies of scale in the long-term future of water infrastructure.