The world is facing a dramatic crisis of clean drinking water by mid-century.

Living on the Blue Planet, one must wonder how water availability could be a source of concern. Yet, as the graphic shows, only 2.5% of all the water on earth is freshwater and of that only 1% is easily accessible. The bottom line: only 0.007% of the planet’s water is available for human consumption. With population and global temperature increasing, water resources are under severe pressure. About 850 million people, one in nine, do not have access to nearby clean, affordable water. Water shortage will be one of the major environmental challenges of this century.

The World Water Forum, held in Brasilia in March, 2018, predicted that more than 5 billion people could suffer water shortages by 2050. Water demand will increase, driven in large measure by population increases in developing countries. Water pollution is a huge problem with almost every river in Africa, Asia, and Latin America polluted. Agricultural runoff of fertilizers and pesticides continues as the most significant contributor, but 80% of industrial and municipal wastewater is discharged without treatment.1

As with fossil fuels, the planet has been afforded ancient supplies of ground water in aquifers. While they could theoretically be replenished over time, they are being depleted faster than they can recover. The question, then, becomes “Is water a renewable resource? In many regions, the answer to that will be no.”2

New data from NASA, using its Grace satellite, have revealed a drying out of large areas between the tropics and the high latitudes. What is evident is that the wet areas of the world are getting wetter and the mid-latitudes are getting drier.3

Northern India, where groundwater is being used to irrigate crops of wheat and rice has seen a rapid decline in available water. The situation is compounded by the melting of the Himalayan glaciers, of which perhaps two-thirds could be gone by the end of the century.4 In the Mideast, Turkey has built 22 dams on the Tigris and Euphrates rivers over the last thirty years. This has led to a an unsustainable dependence on groundwater with the area now nearly a third below the normal state. Climate change knows no boundaries, though, as the chief executive of the Environment Agency has warned that England could run short of water within 25 years.5

Predicted Water Availability per person in 2025

Source: United Nations Environment Programme

In Central Asia, five countries which shared energy and water during the Soviet era, have entered into a conflict oriented era after the collapse of the USSR. The water rich countries, Tajikistan and Kyrgyzstan, are now faced with a water shortfall as climate change reduces the flow in the Amu Darya River. The other three, Kazakhstan, Uzbekistan, and Turkmenistan, began exporting electricity and natural gas, forcing the water countries to use more water for power generation. The result has been political upheaval and instability throughout the region.

China, where almost a fifth of the world’s population lives, has only 7% of the world’s fresh water. It then heavily pollutes much of what is does have. A third of its lakes and rivers are unfit for human use and three quarters of its urban watersheds are polluted.6 The problem is exacerbated by the practice of historically low pricing of water and encouraging water-intensive agriculture and industry.

To address the water shortage in northern China, it has built the South-North Water Diversion Project which will bring water from southern China north. This involved construction of a 1200 km canal from the Yangtze to Beijing. The project, however, will only facilitate the ongoing crisis by failing to address the inefficient use of water in China.7 Climate change is reducing water availability while a growing population is creating growing energy demand which requires more water. Without fundamental changes, China could face water shortfalls by 2030.

The Mediterranean area, Southern Europe, parts of the Middle East and Africa are especially vulnerable to climate change. As precipitation in this area decreases, current groundwater usage will lead to water levels below critical thresholds in the near future. The crisis could occur quite rapidly in southern Europe, especially Italy and Spain.8

Conflict over water will become more frequent in the decades to come. That conflict is more likely to occur where there is a “transboundary” or shared access to water. Such areas include the Nile, Ganges-Brahmaputra, Indus, Tigris-Euphrates, and Colorado rivers.

United States Water

The United States is fortunate to have abundant water resources. The Great Lakes is the largest freshwater lake system in the world, and a thread of river systems extends throughout the country.

Every River in the United States Credit: Robert Szucs

Americans, however, use twice the global average of water, and climate change, population increase, and economic growth will produce water related problems over the coming decades. Droughts and floods are now commonplace. A recent report by the Natural Resources Defense Council and Tetra Tech estimated that by 2050, 70 percent of US counties could face water shortages. A more urgent concern is that water managers in 40 of 50 states expect water shortages in the next 10 years.9

A new study just released by the American Geophysical Union found that the central and southern Great Plains, the Southwest and central Rocky Mountain States, and California all will face serious water shortages in the coming decades. The report suggests improvements in irrigation efficiency and transfers of water from agriculture to other sectors will help to mitigate the shortfalls.10

If we move to the city level, at least a half-dozen US municipal areas are under significant water stress.11

Miami @ 2°
Miami with 2° Warming - Source: Climate Central


Miami: Rising seawater levels are seeping into the city’s aquifer. In the early 20th Century, Miami drained nearby swamps leading to the seawater contamination of the Biscayne Aquifer, its main source of fresh water. The city is attempting to engineer its way through the rising sea levels, but the city’s drinking water may be the the more pressing issue.

Miami is built upon the 4,000 square mile Biscayne Aquifer, a shallow porous limestone layer from which the city draws its drinking water. The water is sent to water treatment plants built decades ago, but not designed to filter the contaminants like those from the hazardous Superfund site that sits a few blocks away from the Hialeah plant. The site is the residue from the Miami Drum Services company that for 25 years rinsed containers for an assortment of toxic chemicals.

The heavy rains that typically inundate southern Florida could dislodge the toxic chemicals from the 13 Superfund sites in the area, forcing them into the aquifer. The problems don’t end there. Twenty years ago, the state approved a large-scale limestone mining project between Miami and the Everglades. The blasting of holes for the mining near the drinking water well-fields has created another source of contamination.

The urban development of Southeast Florida was characterized by the use of septic tanks rather than the more expensive process of creating local sewer systems. A septic tank allows for the leeching of liquids into the surrounding area which is supposed to be above the ground water level. In this area, the water table is very high and during the wet season exceeds the two-foot threshold necessary to protect the aquifer.

All these issues and the salt water invading the limestone aquifer will drive a hard bargain: how much are the residents willing to pay to protect their water?


It would take a book to detail the water situation in California. The state has built an extensive delivery infrastructure throughout the state. Despite this extraordinary system, it is still dependent on seasonal rains in a semi-arid Mediterranean environment. Although surface water makes up most of the state’s supply, More than 40% of the population depend on groundwater for at least part of their water, and many small to medium sized towns are entirely dependent on it. Drought is and has been a common occurrence in California, and climate change will likely produce increased weather volatility. This hydrological cycle intensification will seriously challenge the existing water infrastructure of storage and distribution.12
California's 65 MAF Source: The Delta Plan


Atlanta is the largest American city without a major body of water nearby, and the relentless growth (fourth fastest in the US) in its population makes it increasingly vulnerable to drought. Access to groundwater is limited because of the granite layer underlying the region, and ten years ago, after a prolonged drought, it’s main water reservoir, Lake Lanier was classified as a “dead pool.” 

In June 2018, the Supreme Court sided with Florida in the 30 year legal battle over the water supply from two shared river basins -the Apalachicola-Chattahoochee-Flint (ACF) and the Alabama-Coosa-Tallapoosa (ACT). The issue remains unresolved, though, awaiting a further ruling from a “Special Master” to verify Florida’s claim that it needs more water.

Salt Lake City

Utah is the second driest state in the nation, and Salt Lake City is heavily dependent on the snow pack runoff from from four Wasatch Front Streams. As temperatures climb in the Inter-mountain West, snow diminishes as more moisture falls as rain. The timing of the runoff is important and challenges the city’s storage capabilities.

Historically, Utah has not used its full allotment of Colorado River water and now wants to build a 140 mile pipeline to Lake Powell. It will move its previously unused allotment of water 2,000 vertical feet via five pumping stations and six hydroelectric plants across the Paria River and the Grand Staircase-Escalante Monument. Though Utah has legal rights to the water, the Colorado is already over-allocated.

This is all about growth and there is no growth without water.

The Ogallala Aquifer

The Ogallala Aquifer is almost mythic in its import to the middle third of America.13

  • If spread across the US the aquifer would cover all 50 states with 1.5 feet of water.
  • If drained, it would take more than 6,000 years to recharge.
  • More than 90 percent of the water pumped is used to irrigate crops.
  • $35 billion a year in food and fiber depend on the aquifer.

This map shows changes in Ogallala water levels from the period before the aquifer was tapped to 2015. Declining levels appear in red and orange, and rising levels appear in shades of blue. The darker the color, the greater the change. Gray indicates no significant change. Although water levels have actually risen in some areas, especially Nebraska, water levels are mostly in decline, namely from Kansas southward.14

Well outputs in the central and southern parts of the aquifer are declining due to excessive pumping and drought. Global warming is likely to produce prolonged and intense droughts over the coming decades.


Average Summer Temperature

Source: American Climate Prospectus

With a population of  29 million, the Texas economy is built around transportation and energy. Its reliance on natural resources makes it especially vulnerable to the dramatic increases in temperature predicted this century from climate change.

El Paso, in the Chihuahua desert has depended on water from the Rio Grande for as much as half its water supply. The Rio Grande, though, is dying.14 The third-longest river in the US, in the summer of 2018 it almost stopped flowing from Colorado to New Mexico. The water that does reach Texas is from reservoir releases or imports from other basins. It’s the classic story of water in the American West. Legal feuds, draining by farmers, a drying climate.

Ground water in Texas is being drawn down relentlessly under a set of laws from 1904 known as the “Rule of Capture” which allows landowners to pump water without constraint. San Antonio, ranked as the city most likely to run out of water in a study by the Environmental Hydrology Laboratory at the University of Florida, relies on the Edwards Aquifer which is being drawn down without sufficient recharge.

Surface water is treated differently, and the result is a disorganized set of processes that fails to integrate the two. It has only been five years since the statewide drought of 2010 – 2015 which caused record agricultural losses and fires. A movement is growing to create a resource management system, One Water, which would include all the water within a specific geography as a single source to be managed holistically and sustainably.


By Melikamp - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17747851

Is Phoenix the least sustainable city in the world? In the 1950s Phoenix was a city of 250,000 and a beautiful oasis in the desert covered with fragrant citrus groves. Today, it is a “megapolitan” of over 4.7 million and one of the fastest growing areas in the country. It sprawls across 14,566 square miles. Its annual rainfall of less than 8 inches per year means that the area is dependent on water from Lake Mead which is fed by the Colorado River and over 300 miles away by the Central Arizona Project. The water must be pumped up 2,900 feet and necessitated the construction of a massive coal-fired power plant, the Navajo Generating Plant, to provide the electricity to do this. The Colorado River, though, is drying up and Lake Mead water levels continue to drop as it provides water for 25 million people in Arizona, California, and Nevada. To address this situation, Phoenix is preparing for a future that might not include water from Lake Mead. Its main source of water, the Salt River Project, is being augmented by innovative water strategies like the Arizona Water Bank, a system of seven water banks to store unused water from the Colorado. It also has other aquifers filled with enough water to last the city for years. These projects and others including, possibly, desalinization would appear to make the future seem manageable, but that’s a problem. There is no political will to manage growth so it continues, and the question remains: is it human folly to assume that a city of this size can be sustained in an arid environment where temperatures are predicted to rise dramatically by as much as 10 degrees Fahrenheit by 2090? 

Cities Around the World

São Paulo

Brazil is rich in water, but in 2015, the water supply of São Paulo, a city of 22 million fell to less than 20 days during a long drought. Today, half of its water basins face critical shortages and it is importing water. The chronic water availability shortfall is made worse as only 60% of sewage is treated leading to wide-spread water pollution.

Continuing  Amazon deforestation also contributes to the problem. The rain clouds for Sao Paulo traverse the Amazon. Deforestation reduces the moisture content of the clouds. A recent study found that additional deforestation of as little as 20% to 25% could push the Amazon hydrological system beyond a tipping point making it no longer able to support a rain forest ecosystem. The rain forest would then be replaced by savannah.


More than half of the city’s residents rely on water tankers filled from wells. Now a city of 11 million, Bangalore has added water from the Cauvery river to its water supply and intends to supplement that with water from the Nethravati river. This will ease the shortage, but it appears that efforts to encourage water conservation have done poorly. Water pollution is also a huge problem with 85% of its lakes unfit for human consumption. The city does not have a single hydro-geologist on its Water Supply and Sewerage Board.


The 21 million people in Beijing are facing more than air pollution. Long dependent on ground water, they are using so much water that the city is sinking as the water table is drawn down between one and 3 meters a year. As the aquifers are depleted, it is becoming more reliant on water from the South to North diversion project, the unfinished expansive system of waterways and canals bringing water to the north from the wetter south.The project saved the city during the recent record drought, but in the long term it is not likely to suffice because the system was based on the now diminishing water supplies of 1950 to 1990. If and when completed the project will not fill the predicted water shortfall as population grows. To make matters worse, nearly 40% of Beijing’s surface water is badly polluted, and about 2 million cubic meters of untreated wastewater was released in 2015.

Nile Delta Source: AsiaNews


Egypt’s near future is threatened by potential water and food shortages by 2025. Its dependence on the Nile River cannot be overstated. Originating in Burundi, it provides 97% of Egypt’s water and flows northward for 4,130 miles through eleven countries to the Mediterranean Sea. Most of the Nile water comes from Ethiopian rains between July and September. The rains have become unpredictable, though, threatening the agricultural livelihoods of many along the river. Ethiopia is in the process of constructing the $5 billion Grand Ethiopian Renaissance Dam (GERD), putting Ethiopia in control of the flow of the river and threatening Egypt’s traditional position as the user of most of the river’s water. With its population predicted to grow from 94 million to 120 million by 2030, Egypt may approach the threshold for “absolute water scarcity.” Almost half of Egypt’s population lives on the Nile Delta where a dense system of canals and irrigation use most of what water there is. Poor garbage, sewage, and pollution management have so despoiled the Nile, though, that some farmers must rely on ground wells. As sea levels rise this century, much of the northern part of the delta will be lost.


A water and sanitation crisis. The largest city in Southeast Asia (>10 million), Jakarta is part of the metropolitan area known as Jabodetabek which exceeds 30 million. It covers almost 1,700 sq. mi. with a population density of 37, 460 per square mile. The first thing to know about Jakarta is that has been and continues to sink at an alarming rate. Sitting on swampy land against the Java Sea, it has 13 rivers running through it. Flooding is frequent and water pollution is endemic. Most people get their water either from the rivers or ground water. Both sources are considered contaminated.

Jakarta The Fastest Sinking City in the World Source: BBC


Russia has plenty of water, the problem is that much of it is polluted. This is the legacy of Soviet-era dumping when the rivers were used for waste disposal of chemicals and sewage. In Moscow, both surface water and groundwater are polluted. The same can be said for St. Petersburg where the water comes from the polluted Lake Ladoga. Without government policies to restrict the pollution, large-scale dumping continues. As in China, there is a geographic mismatch between the location of most of the freshwater in Russia, which is in Siberia, and the population in Western Russia. The distance makes transfer impractical at this time. 


A number of typical issues threaten the water supply in Istanbul which relies on surface water from eight regional reservoirs. Istanbul is now about 15 million people. The rapid population growth has increased demand which has to date been matched with a sustainability master plan including total water storage capacity increases now and in future decades. The long term concern, however, is that climate change is expected to raise surface temperatures in Turkey between 2 and 3 degrees C by 2040 with an accompanying decrease in precipitation. Pollution is also a concern with some sewage still going untreated and a dated water treatment infrastructure.

Mexico City as it sprawls out across the Valley of Mexico Source: WorldAtlas

Mexico City

Another of the world’s largest cities, Mexico City, home to 21 million people and 27 million including surrounding areas, is predicted to reach 30 million by 2030. Often the water problem in Mexico City is too much water as flooding events are becoming more prevalent with climate change. Much of the rainwater is lost as runoff so little reaches its aquifers. The water management infrastructure is ancient, crumbling, and leaves a city that floods with a chronic water shortage. For many, generally the poorest, the water supply is intermittent or non-existent. These depend on the water trucks. There is water available in underground aquifers, but they are being depleted faster than recharged. This means that parts of the city are subsiding as much as 12 inches a year. Every second the city produces about 40,000 liters of sewage, and while a new underground waste-water tunnel has been built, it will not solve the water shortage or subsidence issues.

Cape Town

In 2018, Cape Town avoided being the first major city to run out of water. The opportunity now presents itself to explain why the crisis occurred and appraise the current situation in 2019.

According to PhysicsWorld, the crisis occurred because of a shift in rainfall patterns that pushed the rains farther south. This observation can be applied to other Mediterranean-type climate areas like California and the Iberian Peninsula. The crisis was averted by governmental water restrictions. By late 2018, water levels in the dams had risen to 70% of capacity and water restrictions were eased.

Locals are said to have adjusted their water usage, understanding that this episode may be a precursor of the new normal.

South Asia

If there is one area of the globe that presents a case where all the predicted problems of the next decades coalesce, it’s South Asia where about a fifth of humanity resides. Without GHG emissions mitigation, temperatures across the region are projected to increase by more than 2° Celsius by mid-century. In some areas the high humidity coupled with the warming could produce wet-bulb temperatures of 35°, the limit beyond which humans cannot cool their bodies enough to survive more than a few hours outside.

Extreme Water Shortage by 2040 Source: World Resources Institute
Source: Natural Earth


The water situation here is grim and likely to get worse. Three-quarters of Indians do not have drinking water at home and 70% of the country’s water is contaminated. Water in India is more polluted than that in any other major nation. Because surface water is so polluted, India depends on groundwater and is the highest user of it in the world. Most of the fresh water is used for grain-growing agriculture, including crops like sugar cane, which makes no sense in water stressed India.

Water pollution and contamination are the result of open defecation and practically non-existent water treatment. Almost all the sewage in India is flushed into the rivers. The capital, Delhi, had an estimated population of 18.6 million in 2016. Residents there suffer some of the most polluted air in the world, and the city is now running out of water. The Yamuna River, which flows through Dehli, has been described as ecologically dead, the result of sewage from Delhi and other cities, chemical waste from manufacturing plants, and agricultural pesticide runoff.

Over the last 40 years, India’s population has doubled from 600 million to 1.2 billion. During that same time period, over 30 million water wells have been dug, and areas of northern and eastern India have become hotspots of groundwater depletion. The polluted surface water eventually enters the aquifers with the result that most aquifers are now polluted.

The water crisis threatens public health, farm productivity, the economy, and social stability. Yet, water management policy allows farmers to use whatever they can pump from their wells and provides free electricity to run them. An Indian government study has warned that Delhi and another 20 cities are in danger of running out of water by 2022.


One of the fastest-growing nations in the world, Pakistan has the fourth highest rate of water use. It is also one of the most water stressed countries in the world. 96% of its water is used in agriculture, wasting some 40% in the poorly constructed irrigation systems. The water shortage is so severe that a recent report by the IMF suggests that the country could “run dry” by 2025, running a water deficit of 31 million acre-feet.

Its poor water management and lack of infrastructure mean that Pakistan has little ability to store the water from the rains that accompany the increasingly erratic monsoons. The warming temperatures from climate change will produce higher demand for water while diminishing water supplies and increasing the rate of evaporation.

Karachi, now a city of 15 million, is dependent on two sources for its water: Hub Dam and Keenjhar Lake. The water level in Hub Dam is very low due to lack of rainfall over the last three years. Keenjhar Lake supplies less than half the city’s water need making water available only on alternate days.  A recent judicial report said that 91% of Karachi’s water was unsafe to drink, but many people are forced to drink the contaminated water.

Pakistan is unusually dependent on a single huge groundwater aquifer known as the Indus Basin Aquifer. This aquifer is larger than England and spans the border with India. According to a recent study in Science Advances, the aquifer is contaminated with arsenic. Even so, at current rates of withdrawal, the aquifer may eventually run dry. As in India, electricity and diesel for agriculture are government subsidized, so the water is literally free for well use. Drilling remains unlicensed.

Government agricultural policy encourages farmers to produce water intensive crops and livestock. Significant exports of rice, cotton, and textiles are essentially exports of water. Similarly, beef production consumes huge amounts of water with the meat going to water-scarce countries like Saudi Arabia.

Southeast Asia Glaciers and Rivers

This is where it gets complicated. Pakistan depends on the Indus River for most of its fresh water, but the river is fed by glaciers originating in the foothills of the Tibetan Plateau. It then flows through the disputed territory of Jammu and Kashmir to the Arabian Sea at Karachi. Like the Nile, by the time it gets to the sea, what was once a lush fertile delta is dying.

As noted earlier in the section on glaciers, the Himalayan glaciers are melting because of climate change. This is a very real threat to the long run source for the Indus. At the same time, India has begun building diversions from the headwaters, provoking serious tensions with Pakistan.

The background to this is the Indus Water Treaty of 1960 in which the two countries divided up rights to the various upstream tributaries. The current situation of climate change and huge population increases presents conditions for which the treaty wasn’t designed. Nor does the treaty include China and Afghanistan where its Kabul River provides 17% of Pakistan’s water.

The coming decade will see an onslaught of dam-building in India, Nepal, Bhutan, Pakistan, and China. This can only lead to increased geo-political tensions and environmental risks. The impending loss of glacial melt water later in the century will only complicate the situation.

Latin America

Ica Valley, Peru

The Ica Valley, and the recent agricultural boom there, exemplify the the worst of humanity’s inability to manage the world’s natural resources. The area gets about 1 inch of rainfall per year, but its warm dry climate has been attractive to agri-business. In this desert water intensive crops like asparagus, grapevines, and avocados are grown for export to the United State, Europe, and Asia. The water used for this produce is primarily groundwater, and this has produced a serious conflict with small farmers.

Although there are regulations in place to limit the number of wells in a region, the Autoridad Nacional del Agua estimates that 3 out of 4 wells (1,320 of 1,760) are operating illegally. There is essentially little to constrain the agricultural companies from pumping as much water as they wish, and the underlying aquifer is being drawn down faster than it is being replenished. Agricola La Venta has asked for government permission to use three wells and send that water eight miles via a pipeline to a farm growing table grapes for export. 

It’s no wonder that residents of the the towns in the area feel threatened for they are only getting water once every 10 days. Even so, the agriculture has generated an economic boom and provides employment to 40% of the region’s people. It’s a familiar story and will last until the water runs out, at which time the companies will move on, leaving another depleted aquifer. It’s unclear how long the agriculture can be maintained and as water becomes scarce, the companies are pressuring government departments to focus on transferring more water from the Amazon basin.

Peru is also grappling with international mining companies, which are accused of polluting rivers and diverting river flow from farmers. The conflict is so severe that martial law has been declared in two provinces, and there are currently 200 current conflicts between mining companies and communities.

Dominga Uño, a Bolivian shepherd and farmer who lives in the highlands. She lost her crops and many sheep in 2012 due to severe weather Photo: EC/ECHO / R. Silva, Flickr.


The Andean glaciers are melting and droughts have been commonplace, putting Bolivia in an historical state of water resource stress. 2016 and 2017 were years of severe drought throughout the country and in La Paz.

In November, 2017, in collaboration with the Stockholm Environment Institute (SEI), a “natural water balance” model was created which appears to represent a major step in managing the country’s water resources. 40 Bolivian water planners have been trained in the use of the model to assess current and future water availability. 

It is encouraging to see projects like this as it represents an effort by a organization from the developed world to transfer expertise to the developing world.