Water supplies are being threatened by climate change, endangering food and energy supplies as well

Any discussion of climate change and water issues runs the risk of creating an artificial distinction between many fundamentally intertwined forces, with water as just one facet of a complex set of challenges. Because climate change interacts not just with water security but also with energy and food security, current thinking has moved toward the nexus approach that unifies them.

The “Global Risks 2011” report delivered at the World Economic Forum examined the risk correlation between the water, energy, and food sectors, stating:

Any strategy that focuses on one part of the water-food-energy nexus without considering its interconnections risks serious unintended consequences.

Since then, the Water-Energy-Food (WEF) Security Nexus has become a widely discussed subject in geopolitics. Yet the WEF Security Nexus model does not create a full picture of the dynamic systems of our world.

Drought and Water Stress

One of the most serious effects of climate change, which already impacts large swaths of the world’s population, is the lack of enough safe, usable water to support populations, particularly in areas that have never experienced such severe shortages before. Drought, water stress, and water scarcity are stages of the same problem.

When rains fail to arrive for years on end, and a hotter climate causes more evaporation of surface water, tapping groundwater supplies can deplete available resources to the point of causing irreparable damage.

Groundwater depletion harms the capacity of aquifers to hold water as it causes the ground to sink (subsidence), and allows saltwater intrusion in coastal freshwater aquifers. Saltwater intrusion is exacerbated by sea-level rise caused by the melting of glaciers and icecaps caused by climate change.

Overuse of surface water bodies, such as lakes and rivers, leads to breaches of critical flow limits in rivers that can push river ecosystems past the tipping point, shutting down hydroelectric power plants, blocking navigation, stopping the natural process of aquifer recharge, and driving desertification. Groundwater depletion from human activity has been shown to make riparian forests more vulnerable to wildfires that release greenhouse gases into the atmosphere, further damaging ecosystems that regulate climate.

Other major human activities that compound the effects of climate change on freshwater resources are agricultural irrigation, power generation, pollution, household use, and a wide range of industrial processes.

Adapting to Water Challenges

The increasingly lengthy, frequent, and severe droughts accompanying climate change have now led to the threat of “day zeros” in many major cities of the developed world, as well as the developing world. Some crises were only averted by major desalination build-outs.

• Sydney’s AU$2 billion Kernell desalination plant went online after Australia’s unprecedented eight-year drought, which started in 2001. The plant is now returning to service after the return of drought in 2018.
• In South Africa, Cape Town averted a “day zero” crisis in its third year of drought with a major build-out of desalination, groundwater, and even direct-potable water reuse projects.
• Israel conducted a major build-out of large desalination plants before the onset of its latest drought. But the five-year drought was worse than expected, and the country is now considering building more desalination capacity.
• This summer, after a prolonged drought, municipal taps ran dry in Chennai, the “Detroit of India,” sparking unrest.

Without water security, nations can become fragile. Institutions are weakened and become ineffective, populations are stressed by conflict and loss of livelihoods, and infrastructure falls into disrepair. Fragility is a downward spiral.

Finding Solutions for Water Scarcity

In the face of continued climate change, what can be done to protect water supplies? Around the world, solutions vary, and include changes in laws and policies, as well as technological advances.

Water Storage and Watershed Upgrades

Although dam construction was once the most common way to increase water storage capacity as a buffer against drought, dams have become problematic in terms of the aquatic environment and in terms of removal costs when they reach the end of their service lives.

California has responded proactively to persistent drought conditions with a $7.5 billion outlay for water storage proposals and environmental protection of water resources, along with establishing a legal framework to fund watershed upgrades. The Brazilian city of São Paulo has started a similar program to protect its surrounding cloud forest.

Water Reuse and Recycling

Because the world’s natural systems produce fresh water on their own schedule, many technologies have emerged to help speed up the process, and recycled wastewater is being used for irrigation, purple pipe applications, indirect potable reuse, and even direct potable reuse. The technology is in place for the full range of water reuse applications, but in some parts of the world there still are psychological barriers that have slowed the adoption of water reuse. But as the need grows, this so-called yuck factor is gradually being overcome. It simply makes sense to make the most of every drop.

• Nonpotable reuse strategies are as varied as the entities that use them. Many heavy industries have found they have more control over the cost, quality, and supply of their process water when they treat and reuse it in-house. Hotels and resorts find huge savings in reusing laundry water to irrigate their golf courses. Airports, industrial parks, and corporate campuses, which often are like small cities, have seemingly endless opportunities to reuse their water from bathrooms, to runway washing, to rental auto washing, to irrigation of landscaping.
• Indirect potable reuse uses highly treated sewage treatment effluent to replenish natural systems from which drinking water is drawn. Highly treated effluent can be used for managed aquifer recharge. Perth, Australia, recharges its groundwater with 10% of the city’s wastewater. Much of Sydney’s drinking water is recycled wastewater that is discharged and diluted in rivers and then introduced to municipal water systems downstream.
• Wastewater treatment technology has progressed to the point that even raw sewage can be efficiently turned into safe, sanitary, good-tasting drinking water, an application that is called direct potable reuse. Direct potable reuse is in use in Asia and South Africa, and legal barriers to direct potable reuse have been removed even within the continental United States in Arizona. Even some award-winning craft beers have been brewed with highly purified wastewater that originated in municipal sewers to prove the point that direct potable water reuse is here and it is delicious.

Decentralized Treatment Solutions

Sometimes, the brunt of climate change is felt in remote areas of the developing world, where it has been a challenge to extend water service. In these cases, decentralized treatment is an important solution. This means treating water adjacent to source and need, which eliminates the need for prohibitively expensive pipelines. New desalination and wastewater treatment technologies are available in plug-and-play shipping containers, making small- or medium-scale decentralized treatment viable for a vastly expanded market. One major decentralized project in China features 80 Fluence Aspiral™ wastewater treatment plants placed every 50 km along the Hubei highway system. The Smart Packaged plants feature energy-efficient membrane aerated biofilm reactor (MABR) technology. Many Fluence desalination plants are used by resorts and in remote areas that find it difficult or impossible to connect to distant water infrastructure.

Contact Fluence to discuss treatment options to safeguard water supplies in the face of climate change.