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Day Zero: the coming global water crisis and what we can do about it
Day Zero: the coming global water crisis and what we can do about it
POSTED SEPTEMBER 25, 2018
This global map of freshwater stored on land for February 2016 using data from the Gravity Recovery and Climate Experiment. Credit: NASA
Besides the air we breathe, nothing is more essential to our survival than water.
Besides the air we breathe, nothing is more essential to our survival than water.
Access to clean water is far from universal today. According to the non-profit Water.org, 844 million people live without access to safe water and 2.3 billion without improved sanitation. One million people die from water-, sanitation- and hygiene-related disease each year.
Access to clean water is far from universal today. According to the non-profit Water.org, 844 million people live without access to safe water and 2.3 billion without improved sanitation. One million people die from water-, sanitation- and hygiene-related disease each year.
And, thanks to changing climate, decaying infrastructure and burgeoning city populations, access to water is going to get more problematic in the future across much of the world. A global, satellite-based study of Earth's freshwater distribution found that Earth's wet areas are getting wetter, while dry areas are getting drier. The data suggest that this pattern is due to a variety of factors, including human water management practices, human-caused climate change and natural climate cycles. The study was published in the May 17, 2018 issue of the journal Nature
And, thanks to changing climate, decaying infrastructure and burgeoning city populations, access to water is going to get more problematic in the future across much of the world. A global, satellite-based study of Earth's freshwater distribution found that Earth's wet areas are getting wetter, while dry areas are getting drier. The data suggest that this pattern is due to a variety of factors, including human water management practices, human-caused climate change and natural climate cycles. The study was published in the May 17, 2018 issue of the journal Nature
Day Zero
Day Zero
Earlier this year, the city of Cape Town in South Africa, narrowly escaped running out of water - as in "nothing comes out of the taps". A three-year drought - the worst in a century - moved the city towards "Day Zero" when the taps would be shutoff and people would need to queue for their water. The city's water supply shortage was the result of a combination of physical, social, and political factors. In addition to the drought, population growth and government mismanagement produced one of the worst urban water crises in recent memory.
Earlier this year, the city of Cape Town in South Africa, narrowly escaped running out of water - as in "nothing comes out of the taps". A three-year drought - the worst in a century - moved the city towards "Day Zero" when the taps would be shutoff and people would need to queue for their water. The city's water supply shortage was the result of a combination of physical, social, and political factors. In addition to the drought, population growth and government mismanagement produced one of the worst urban water crises in recent memory.
Day Zero was projected to be in April, 2018 but, helped by a fortuitous rainy season, Capetonians avoided it (for now) by cutting their water usage by 50% over a three year period. Cape Town introduced severe household water restrictions, banned washing cars, installed water management devices at the homes of excessive water users, "throttled" water supply to all suburbs, banned filling of swimming pools, and instituted a city wide publicity campaign to rally residents and businesses.
Day Zero was projected to be in April, 2018 but, helped by a fortuitous rainy season, Capetonians avoided it (for now) by cutting their water usage by 50% over a three year period. Cape Town introduced severe household water restrictions, banned washing cars, installed water management devices at the homes of excessive water users, "throttled" water supply to all suburbs, banned filling of swimming pools, and instituted a city wide publicity campaign to rally residents and businesses.
Cape Town is not alone. Without prudent action, many large cities will face their own days of reckoning in the coming years and decades. Mexico City, Jakarta, Sao Paolo, Beijing, Cairo, Bangalore, Tokyo, and London appear to be the cities in most danger of facing their own "Day Zero".
Cape Town is not alone. Without prudent action, many large cities will face their own days of reckoning in the coming years and decades. Mexico City, Jakarta, Sao Paolo, Beijing, Cairo, Bangalore, Tokyo, and London appear to be the cities in most danger of facing their own "Day Zero".
Here in the US, the Flint crisis is a reminder of what poor governance can do. According to the 2016 task force appointed to study the Flint fiasco, Michigan state agencies overseen by Gov. Rick Snyder and a series of emergency managers appointed by the governor were to blame for allowing contaminated water into Flint homes.
Here in the US, the Flint crisis is a reminder of what poor governance can do. According to the 2016 task force appointed to study the Flint fiasco, Michigan state agencies overseen by Gov. Rick Snyder and a series of emergency managers appointed by the governor were to blame for allowing contaminated water into Flint homes.
California's recent multiyear drought led to some of the state's driest years on record. Fortunately, about half of the state's urban water usage is for landscaping, so it was able to cut back on that fairly easily. But water for cities may not be the biggest issue with California's water supply:
California's recent multiyear drought led to some of the state's driest years on record. Fortunately, about half of the state's urban water usage is for landscaping, so it was able to cut back on that fairly easily. But water for cities may not be the biggest issue with California's water supply:
"An estimated 500,000 to 1 million people in California's central valley who have trouble accessing water, or whose water doesn't meet federal clean water drinking standards...Geography, politics, and an uncooperative climate have converged to make California's water system—the most engineered one in the world—unpredictable at best and dangerous at worst. First constructed in the 1960s, the state's maze of tunnels and dams carry melted snowfall and freshwater from Northern California, where two-thirds of water falls, down to the drier southern part of the state. Along the way, it passes through the central valley to be used for agriculture (California produces an estimated 25 percent of food sold in the United States, more than any other state). But during times of severe drought, likely exacerbated by climate change, these carrier systems are overtapped, which can lead residents and growers to scramble for water for their farms and families." (MindBodyGreen.com Apr 20, 2018 California Water Crisis- link below)
What we can do
What we can do
1. Water conservation - reducing our personal water consumption - is a first step in helping to resolve the coming crisis. The Cape Town experience shows how much can be accomplished by an aware, motivated community, how much water can be saved if we put our minds to it. Care2.com [link below right] has some suggestions.
1. Water conservation - reducing our personal water consumption - is a first step in helping to resolve the coming crisis. The Cape Town experience shows how much can be accomplished by an aware, motivated community, how much water can be saved if we put our minds to it. Care2.com [link below right] has some suggestions.
Also:
The US Geological Survey's Science School has a quiz on the water requirements for things like a cup of coffee, a pound of wheat, an orange, etc. It's an eye opener.
2. An even larger potential for conservation lies in improved irrigation and agricultural practices. Some 70 percent of the world’s freshwater is used for agriculture. Improving irrigation can help close supply and demand gaps. In certain cases profligate irrigation practices meant for an earlier era has weakened the ability of farmers to provide food and fiber to a growing world. What we eat also impacts water usage. A 1/3-pound burger, for example, requires 660 gallons of water. Most of this water is for producing beef (see below). One pound of beef requires 1,799 gallons of water, which includes irrigation of the grains and grasses in feed, plus water for drinking and processing.
2. An even larger potential for conservation lies in improved irrigation and agricultural practices. Some 70 percent of the world’s freshwater is used for agriculture. Improving irrigation can help close supply and demand gaps. In certain cases profligate irrigation practices meant for an earlier era has weakened the ability of farmers to provide food and fiber to a growing world. What we eat also impacts water usage. A 1/3-pound burger, for example, requires 660 gallons of water. Most of this water is for producing beef (see below). One pound of beef requires 1,799 gallons of water, which includes irrigation of the grains and grasses in feed, plus water for drinking and processing.
3. Infrastructure maintenance - fixing leaks and preventing pollution and contamination - is another critically important step. In England, for example, an estimated 20% of all water leaks out before it even reaches homes. In Mexico City, close to 40% of the water in the system is lost through leaks. Monitoring and quickly repairing leaks in the water distribution system is essential - especially for large cities and complex distribution systems, such as California's. Likewise, measuring and monitoring water quality is essential to human health and biodiversity. This issue rears its head in many forms and can be addressed in just as many ways. Water pollution is another cause of water scarcity. The sources of water pollution include pesticides and fertilizers that wash away from farms, industrial and human waste that is directly dumped into rivers without treating it in water treatment plant. Oil spill on the ground, waste water leakage from landfills can seep underground and may pollute the groundwater making it unfit for human consumption.
3. Infrastructure maintenance - fixing leaks and preventing pollution and contamination - is another critically important step. In England, for example, an estimated 20% of all water leaks out before it even reaches homes. In Mexico City, close to 40% of the water in the system is lost through leaks. Monitoring and quickly repairing leaks in the water distribution system is essential - especially for large cities and complex distribution systems, such as California's. Likewise, measuring and monitoring water quality is essential to human health and biodiversity. This issue rears its head in many forms and can be addressed in just as many ways. Water pollution is another cause of water scarcity. The sources of water pollution include pesticides and fertilizers that wash away from farms, industrial and human waste that is directly dumped into rivers without treating it in water treatment plant. Oil spill on the ground, waste water leakage from landfills can seep underground and may pollute the groundwater making it unfit for human consumption.
4. Cape Town's recent water crisis highlights the need for better urban planning and management. Steps can be taken to avoid urban water crises. In general, a “portfolio approach” that relies on multiple water sources is probably most effective. Cape Town has already begun implementing a number of water-augmentation projects, including tapping groundwater and building water-recycling plants. (Scientific American, Aug 1)
4. Cape Town's recent water crisis highlights the need for better urban planning and management. Steps can be taken to avoid urban water crises. In general, a “portfolio approach” that relies on multiple water sources is probably most effective. Cape Town has already begun implementing a number of water-augmentation projects, including tapping groundwater and building water-recycling plants. (Scientific American, Aug 1)
"Metropolitan leaders should be thinking about meeting long-term needs rather than just about daily requirements. Good organization and financial accountability are equally critical. And planning efforts should include diverse stakeholders from the community. One major challenge is providing services to informal areas, which develop haphazardly, without any government foresight. Such regions often lack basic resources—a well-planned water supply among them...As the climate warms, extreme droughts and vanishing water supplies will likely become more common. But even without the added impact of climate change, normal rainfall variation plays an enormous role in year-to-year water availability. These ordinary patterns now have extraordinary effects because urban populations have had a tremendous growth spurt: by 2050 the United Nations projects that two thirds of the world's people will live in cities. Urban planners and engineers need to learn from past rainfall variability to improve their predictions and take future demand into account to build more resilient infrastructure." (Scientific American, Aug 1)
5. Finally, we can employ innovative technology to help solve the water scarcity problem. Among the technologies available or under development:
5. Finally, we can employ innovative technology to help solve the water scarcity problem. Among the technologies available or under development:
Solar-powered water purifiers
This has huge potential in developing nations by addressing the urgent health problems associated with contaminated water. "Researchers report they have developed a cheap solar still, which uses sunlight to purify dirty water up to four times faster than a current commercial version. The raw materials cost less than $2 per square meter. The technology will “allow people to generate their own drinking water much like they generate their own power via solar panels on their house roof,” says Zhejun Liu, a visiting scholar at the State University of New York (SUNY) in Buffalo and one of the study’s co-authors. (Science, Feb 2, 2017)
Recharging aquifers/groundwater
"According to a 2012 UN report on The World’s Water, groundwater retraction has tripled in the past five decades because of industrial and agricultural uses. For this reason, governments and organizations can undertake measures to recharge aquifers or groundwater by undertaking projects aimed at infiltrating or injecting excess surface water into the underground aquifers. This may include aspects such as restoration of watersheds and wetlands and the practice of green infrastructure which aims at reducing impervious surfaces." (Earth Eclipse website)
Water re-use and Effective Water Treatment Technologies
"Water re-use strategies can help alleviate water scarcity in cities, schools, hospitals, and industries. The main strategies here include reuse and recycling and the use of zero-liquid discharge systems. Zero-liquid discharge system is whereby the water within a facility is constantly treated, used and reused again and again without being discharged into the sewer or other external water systems. The non-potable water (greywater) can be used for washing cars, irrigating landscape, industrial processing and flushing the toilets. Such a system allows the waste water that would have been discarded to become a helpful resource. Water re-use or greywater can hence save a lot of fresh water for human consumption in times of water shortage and water stress." (Earth Eclipse website)
Improved, more energy efficient desalination processes
Nearly all, 97.5%, of the water on our planet is undrinkable salt water. Desalination is old technology, known and practiced on a small scale for millenia. Large scale plants were constructed in the 1930's, primarily in the Middle East. By the 1980's, desalination technology became fully commercialized. Distillation methods currently require about 14 kilowatt-hours of energy to produce 1,000 gallons of desalinated seawater. The cost of distillation is high and greenhouse gas emissions are a concern because we need a large amount of electricity to heat water in the thermal plant and generate high pressure. Reverse osmosis and electrodialysis are other currently available technologies for desalination with some advantages over distillation. More exciting, though, is what is on the horizon - processes that can desalinate seawater more efficiently with lower emissions. Here are a few of them:
Engineers at the University of Illinois have taken a step forward in developing a saltwater desalination process that is potentially cheaper than reverse osmosis and borrows from battery technology. (Science Daily, Oct 12, 2017)
A team of scientists from Australia and the US has developed a new water desalination technique, using "metal organic framework" membranes, that can not only make seawater fresh enough to drink, but recover lithium ions for use in batteries. (New Atlas, Feb 11)
According to Penn State researchers, a new desalination technique, called "battery diode ionization") is able to remove salt from water using less energy than previous methods. (PSU.edu, Jan 2)
Technology-aided, data-optimized agriculture
In the agriculture sector, companies such as Microsoft are demonstrating how precision irrigation using smart sensors in fields can give information about soil conditions. Crop data, coupled with drone images of fields, and the use of artificial intelligence to interpret data and model a heat map of the crop area, can all help ensure water is used optimally in food production. According to Alex Mung, head of Water Initiative at the World Economic Forum (WEF). “Emerging fourth industrial revolution technologies – machine-learning, artificial intelligence, advanced sensors, satellite imagery, robotics and others – have the potential to unlock a wealth of previously unobtainable data about water systems at the global, regional, watershed and local level,” (Raconteur.net, Sep 18)
Solar still in water.
QIAOQIANG GAN, SUNY BUFFALO
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