Is water finite?
July 2020 - Anyone who has been reading about water is bound to come across the phrase “water is a finite resource.” This is often presented as so self-evident that it requires no explanation. While there is some truth to this as there is a finite amount of freely available freshwater that falls from the sky each year, it has always struck me as misleading. While water molecules are in fact finite, so are electrons, but who would argue that there is a finite amount of electricity as a result of the finite number of electrons in the world? Just as we can always create more electricity by building more power plants, we can also build new “freshwater factories” that can recycle wastewater into freshwater able to be used for industrial, agricultural, or potable purposes.
The notion of a “freshwater factory” may be new to many but this model is already being deployed around the world. For instance, Israel and Singapore both have less than 1% of the per capita renewable water resources of the US yet through extensive desalination and water recycling are able to generate the majority of their potable water as well as significant industrial and agricultural water from reuse and seawater desalination plants. The fact that these countries lack sufficient available water resources has inspired them to create their own technological and resilient water cycles to speed up the infinite renewal of freshwater supplied elsewhere by nature. If they can do it, what is the excuse for countries with 10x or 100x more available per capita water.
The ability to manufacture water locally enables an entirely different paradigm around water. The faulty premise of water being finite has historically led to a preference for reservoirs and canals over reuse – in effect trying to best manage the available resources rather than create new resources. This approach has not only been costly, environmentally damaging, still subject to droughts, and often involves “robbing Peter to pay Paul.” However, this has been changing in recent years. Freshwater factories in the form of wastewater reuse and desalination plants are increasingly being sought by municipalities, small communities, and industries in order to secure supply, enhance their environment, drought-proof their future, and increasingly to also lower their cost per gallon.
Advances in alternative energy sources are also creating opportunities to secure cheap, reliable power, whether through solar, wind, or micro-hydraulic pumped storage, that help enable decentralized and freshwater factory plants around the world. While agriculture is lagging urban and industrial recycling due to price sensitivity, this too shifting as technologies improve, albeit with cost and brine disposal challenges remaining.
Too long our thinking has been to pray for rain and let the natural water recycle to do our purification work for us or to alternatively re-engineer our landscape on a massive scale rather than simply focus on doing what it takes to turn wastewater or non-potable water into usable water through a technology-driven accelerated synthetic water cycle. Recognizing that fresh water is in fact infinite is a good starting place for any entity thinking about their water future and could help lead to superior and lower cost solutions.