Reverse Flow: Imagining a Desalinated Future

Jul 20, 2019 | 7 Issue, Research

Faced with water scarcity in the 2000s, Israel invested in large-scale desalination. Nearly half of its freshwater now comes from the technology. Photo by Adam Jang/Unsplash.

By Roger Ritsema

Water is a basic human need and our reflexive relationship with it — the continuous dance between adaptation and change — has had a tremendous effect on shaping culture and settlement patterns. The places we choose to live are often near lakes, rivers and streams, for practical but also aesthetic reasons. The geography of water — sources, sinks, flow directions — are well understood and often taken for granted. We know intuitively that fresh water flows from the land to the sea. 

What if, thanks to technological solutions to rising demand, that flow was reversed, with fresh water moving from our oceans to our communities?

Desalination reverses this fundamentally natural premise. What rarely seems to be asked, though, is what are the consequences for people? Cultures? Identities? If environmental impact is a function of population multiplied by affluence and technology, then 7.5 billion humans that continue to get more affluent and use technology in ever-more dizzying ways are taxing the Earth’s resources as never before. Water, the most precious resource of all, the building block of life, is no exception. 

Currently, more than half of the world’s population experiences water scarcity — the inability for water resources to meet demand — in some form every year. Increasing population, urbanization and economic growth are expected to further pressure water resources. In addition, rising temperatures, changing rainfall patterns and over exploitation are reducing available water resources. Although options exist to improve water productivity through conservation and wastewater treatment, to meet rising demand, attention is increasingly being turned to technological adaptation responses such as seawater desalination.

Desalination is the process of separating dissolved salts and other minerals from water. There are many methods, but the most common and large-scale involves forcing water through membrane filters in a process called reverse osmosis. Desalination can be applied to water of varying levels of salinity, such as seawater, brackish groundwater and estuarine water. 

Ultimately, technology is a double-edged sword: it can help solve problems but also exacerbate them of lead to unintended consequences.

Desalination requires a relatively large energy input — which varies by water salinity, plant size and process — and some desalination systems are able to operate using renewable energy, such as solar power. Salty brine is the main discharge. The cost of seawater desalination is higher than conventional water sources, but continues to drop as technology improves and desalination systems are more widely implemented. There are almost 16,000 desalination plants in operation in over 150 countries — almost half in the Middle East — producing more than 95 million cubic meters of clean water each day to 300 million people. 

For rangers at the Biliqo-Bulesa community wildlife conservancy in Kenya charged with protecting elephants and other wildlife from poachers in desert conditions, desalination is replacing a twice-weekly, five-hour journey for fresh water. An American NGO provided a suitcase-sized, ultra-efficient solar-powered desalination unit that produces enough potable water for the entire ranger crew. A side benefit is improved relationships with nomadic herders in the area, since the unit produces enough to share. But, more importantly, what the rangers described as a nightmare trip down rough gravel roads to buy overpriced bottled water has been converted into more presence in the conservancy focusing on their important conservation work. 

The same NGO has plans to deliver desalination units to other remote wildlife ranger stations in Kenya, along with a larger unit to a drought-plagued village. It is hoped that smaller-scale solar desalinisation units can proliferate through aid programs in other drought-stricken areas of Africa, where women and girls do 90 percent of water gathering. Having fresh water close to home could dramatically reduce workloads and free up time for women to participate in the economy and for girls to attend school. Water security in Africa also has potential to help improve people’s lives by reducing violence related to competition for scarce resources.

Water is both a local resource and part of a global system; therefore, we are reliant on the global climate system and upstream neighbours continuing to allow the water to flow. Both can be unreliable. Facing water scarcity in the 2000s, Israel made a strategic decision to invest in large-scale desalination to achieve water security. Four large-scale plants are in operation already and the plan is to build three additional plants, thereby supplying nearly half of Israel’s freshwater from desalination. 

Riparian rights refer to the control of water from upstream to downstream. In Israel’s case, through large-scale desalination the country has been able to bypass the natural geography of water. While Israel and its Palestinian neighbours in the West Bank are lower riparian for freshwater along the Mediterranean, by leading on desalination Israel has effectively become an upper riparian for desalinated water over its neighbours, potentially widening existing power disparities in the West Bank and disrupting geopolitical dynamics in the region. 

Not all of Israel’s desalinated water, however, is destined for human consumption. A certain portion is allocated for natural processes to replenish natural aquifers and flows. Somewhat ironically, then, by reversing flows long siphoned off for human use, technology has potential to restore waterways and riparian areas, which could again provide humans with valuable ecosystem services, protein and the sense of place that drew people to them originally.

Ultimately, technology is a double-edged sword: it can help solve problems but also exacerbate them or lead to unintended consequences. Desalination and other technologies to deliver fresh water to a needy planet are no panacea. Although in their infancy a growing and thirsty world will continue to see a potential technical solution. 

However, from a cultural perspective desalination technology poses more questions than it answers. For instance, how will the developing world participate in building and maintaining expensive desalination plants? How will these plants affect geopolitical power dynamics? Will the development of this technology be used as a reason for humans to continue to live unsustainable lifestyles, or will it help us rejuvenate overtaxed water systems? 

And what does this mean for cultures that derive meaning and identity from gathering and using water from their natural geographies? How will this affect traditional knowledge and wisdom?

Using technology to alter the geography of water has never been done on this scale. While it may prove to be a practical solution for the tangible issue of water scarcity, it may bring social, political, cultural and even psychological consequences that we can’t yet fully anticipate or understand. With every new technology comes a blend of hope and unintended consequences. 

 

Roger Ritsema lives on Wet’suwet’en territory where the beautiful Wetzinkwah flows, and enjoys getting out and experiencing all that northern BC has to offer.