'One water' can solve many supply problems
Current events in California are drawing attention to the current and projected gap between water supply and demand projections. Often cited but worth referencing again are the main drivers in the gap between supply and demand (PDF): Increased population and economic development; the rise of the middle class; and increased demand for energy and food.
California is facing water scarcity due to climate change and increased competition for water. California’s governor recently announced mandatory rationing of water to preserve supplies for agricultural, energy, commercial and residential use. By some accounts, there is only approximately one year's worth of water left in California.
There is no shortage of suggestions as to what is needed to “fix” the water issue in California: not eating beef; tearing up lawns; desalination; shorter showers. These suggestions appear to be driven by what immediately comes to mind and the convenient “top 10” lists as opposed to a holistic view of water supply and demand, including the value of water and innovation in technology and policies.
Many problems, 'one water'
While stakeholders will not start with a clean sheet of paper in addressing water scarcity in California and elsewhere in the world (such as Brazil and China), there is a move towards a “one water” strategy.
“One water” thinking is essentially a holistic view of water as opposed to viewing water in silos. For example, when thinking about water sources, there is a tendency to reference surface water, ground water, salt water, brackish water, potable water and gray water.
With demand exceeding water supply from surface water and ground water, other sources are being more actively examined.
The most obvious is desalination of salt water. However, desalination of brackish water and reuse of treated wastewater is also being viewed as a way to increase the supply side of the equation. Organizations such as the U.S. Water Alliance and the American Water Works Association are getting the word out that we need a “one water” view — an approach to how we move towards water stewardship in a water-scarce world.
There is no “top 10” list of solutions to the “water crisis.” Instead, we need a holistic view of water supply and demand. “One water” thinking to address the supply side and innovative technologies, partnerships and policies to address the demand side of the equation.
The demand side will be driven by moves towards conservation, efficiency, reuse, recycling and “low water footprint” energy, to name a few.