Israelis prove desalinating water a potent strategy for parched Arizona

Sharon Megdal, director of the University of Arizona Water Resources Research Center, and Abraham Tenne, retired Israel Water Authority director of desalination, tour a desalination facility in Hadera, Israel. (Cody Sheehy)

I just returned from an exciting visit to Israel, my 10th since 2010. Each time I visit the region I learn new things about their efforts to manage water resources.

At the WATEC 2015 conference in Tel Aviv, where I was an invited speaker, I had the opportunity to interact with key public and private sector contributors to Israel’s efforts to overcome the scarcity of its natural water resources.

There is palpable excitement associated with the Israel’s success at overcoming the scarcity of natural water resources through a large-scale effort to desalinate seawater. Though some still question the costs and environmental issues associated with these plants, most are confident that this is the right strategy for Israel.

More than one-quarter of Israel’s water supply is now desalinated seawater. It is expected that eventually 80 percent of Israel’s drinking water will come from these plants.

Visiting three plants during one trip dispelled one prior impression I had about desalination plants — namely, that they all look alike. Each is designed to work in its surrounding environment.

The Palmahim plant was so colorful, with each of its reverse osmosis membrane bays painted a different color. More noteworthy was that the private-sector plant operators were able to double capacity without expanding the land area of the plant.

Sorek, the largest reverse osmosis plant in the world, has large membrane tubes installed vertically rather than horizontally. These are just two examples of how engineering and technology have progressed to meet the water supply needs in a country where land is also a scarce resource.

One may wonder what relevance these plants and technologies have to Arizona. Desalination technology can help Arizona make use of some of its brackish groundwater — groundwater that is too salty for human consumption. It can be used as a component of high-level treatment of wastewater.

As Arizona contemplates its strategies for meeting future water demands, reuse of effluent (the outflows of wastewater treatment plants) for additional purposes may require higher-level treatment technology than is currently in place. Much of Israel’s seawater desalination has been accomplished through public-private partnerships (PPPs), where the government enters into agreements with private companies that build and operate the plants.

PPPs, already being used to finance infrastructure in Arizona, are likely to be a greater component going forward. We can certainly learn from Israel’s experiences.

There are also some interesting aspects of Israel’s water pricing. Key is Israel’s effort to have customers recognize the cost of producing incremental or new water. But in Israel, the National Water Carrier’s rates are the same regardless of where customers live.

While Arizona’s decentralized approach to water delivery makes a common pricing structure unfeasible, throughout the state people regularly ask me why we don’t pay more for water. A full answer to this question is surely complex.

Like in Israel, we in Arizona have a strong water conservation ethic. Yet I see stronger and broader recognition in Israel that water is a scarce resource, one that must be managed carefully now and into the future.

While Israel’s strategies have direct relevance as we look to forge Arizona’s water future, it is up to us to figure out our own pathways forward.

Sharon B. Megdal, Ph.D., is director of the University of Arizona Water Resources Research Center. This article first appeared in the Arizona Republic.