THE FUTURE OF WATER

Although about 70% of the earth’s surface is covered with water, most of it is unusable in its current state.  The Earth’s inhabitants must rely upon about 0.75% of all earth’s water for sustenance.  Usable water is eternally recyclable is it goes from seawater to freshwater to irrigation usage to cleansing solvent to sewage removal and back to seawater.  Fresh water supplies ebb and flow with the environment, therefore substantial supplies near urban areas must be kept in reserve.  Owing to increased population, fresh water usage today is at or near the maximum amount sustainable without a dangerous reduction in reserve supply.  The fundamental problem, however, is not a dwindling supply or population increases—it’s mismanagement.  Water usage is more a function of what the world’s population eats and what they wear, not necessarily for drinking or washing/cleaning.  The solution is more a matter of distribution. 

Burgeoning Population:  The United Nations annual world water development report points out that about 1.9 billion people live in areas where water is in short supply.  By including populations that have a water shortage for at least one month per year, the aforementioned total is nearly double.  However, global water consumption has grown 600% since 1920, and could increase by up to another 50% by 2050.  Most of the expected population increase between now and 2050 will likely take place in areas of the world that are already coping with shortages of water.  A larger overall population usually translates into greater population growth in cities, where water systems are often over taxed, and water shortages at great risk.  The burgeoning population will require increases in agricultural output needed to feed the planet.  Agriculture today consumes about 70% of all available fresh water supplies.

Global Warming Impact:  Unknown is the impact that global warming will have on fresh water supplies.  It could likely make the world’s already unequally distributed water supplies, more unequal, as the wet areas would become wetter and the dry areas become drier.  Rising global temperatures could create or aggravate water scarcity to about 8% of the world’s population in as soon as thirty years.  Owing to climate change, a larger percentage of land will need to be irrigated instead of fed by rainfall.  Climate change could also impact regular weather patterns such as seasonal monsoon rains in South Asia, making them more erratic and causing water levels to oscillate in extreme patterns in those areas. 

Impact on Rivers:  Population increases and industrial waste are applying pressure to the usable water from many of the world’s major rivers.  Reliance on sources outside of a country’s borders can further depress available water due to a variety of issues such as glacier melts, rainfall, sediment, drought, and diversion.  Improper planting in dry regions and wasteful flood irrigation also hurts rivers.  Diminished streamflow contributes to existing shortfalls owing to decreased rainfall and increased diversion of water.  The remaining streamflow is often not potable and unsafe to wash with.

Asia’s vital rivers are replenished by summer monsoon rains and melting glaciers.  The Indus which supports irrigation in the Subcontinent provides a flow that is 95% used either as agriculture, or by humans for drinking and washing.  The glaciers are shrinking, and will cause the flow to decline after the year 2050; while in the same time frame the population growth in the area will climb dramatically. 

Groundwater:  Subterranean aquifers are a major source of water in many parts of the world and are replenishable by rainfall.  In many places the aquifers are polluted with arsenic, nitrates, salinity, and fluorides.  Some of groundwater’s pollutants are present naturally in aquifers in safe quantities, but industrial effluent, and seepage from landfills, septic tanks, and underground gas tanks, along with pesticides and fertilizers have replaced bacterial pollution as the most significant problem.  Increased demand forces the pumping of the aquifers to lower levels where contamination is more likely to take place.  In areas where the land is planted with crops, solar radiation is reflected away more so than where the land is covered by forest.  The ground temperature becomes cooler impacting the differences in temperature between the ground and the sea.  This can cause changes in weather patterns that bring rain in off of the ocean. 

A great long-term uncertainty surrounds the future of groundwater used primarily for agriculture in many arid parts of the world.  About half of the world’s groundwater supply is naturally replenished to an equilibrium inside of 100 years.  Further, studies have shown that groundwater systems respond much slower to the impacts of climate change than do surface water systems.  Consequently, it could take decades to evaluate the impact of groundwater withdrawal on agriculture and populations, not to mention solutions for shortages and/or disruptions. 

Desalination:  Modern technology has uncovered newer methods of desalinating water thanks to a process known as reverse osmosis.  This process passes water across a semipermeable membrane that removes ions, chemicals, unwanted molecules, and other harmful pollutants.  Reverse osmosis processing plants in usage today provide substantial amounts of desalinated water which finds its best usage in irrigation.  Reclamation of waste water is also a growing activity that, thanks to ultra-violet disinfection, can be used for drinking and washing. 

Although desalination is a growing solution in certain parts of the world, it probably can’t be thought of as a universal solution.  One reason is that some of the driest parts of the world are a long way from the ocean, and transporting ocean water for desalination may have to cross mountain ranges and/or go around or under urban areas.  Further, pipelines would be required to transport the desalinated water many miles to locations where demand exists.  Another reason is that most methods of desalination require copious amounts of energy, raising the cost of the process.  A third reason is the huge amount of brine (salty water) that is created and must be maintained so that it doesn’t leach into the soil until it can be safely returned to the sea.  Around the world, desalination produces about 50% more brine than it does freshwater. 

Conservation:  If desalination is the most expensive way to produce a cubic meter of freshwater, then conservation is the cheapest way.  The best place to look for water savings is in agriculture as it can account for as much as 90% of all water usage in places with distressed water supplies.  The usage of “flood” irrigation loses as much as half the water used to evaporation, whereas the “drip” method delivers the right amount of water to agriculture without much waste.  Food is wasted in the supply chains around the world necessitating more agriculture production and more water usage.  Leakages in water distribution systems lead to water wastage that brings a never-ending spiral—leaked water doesn’t reach its destination and therefore is not paid for, so the water district has reduced revenue and is hard pressed to pay to fix the leaks, old and new.  To achieve a goal of good conservation the best avenue is for consumers to change their tastes in certain food and clothing.  A kilo of cotton requires nearly 10,000 liters of water—beef over 15,000 liters.  Wine growing grapes are very consumptive of irrigation water to the extent that the ground water in Northern California wine growing locations is slowly becoming depleted.

Impact of Public Policy:  A treaty in 1960 divided the outflow of the Indus River into Pakistan and India.  In 2006 China built a dam in the headwaters of the Indus without meeting with or explaining their intentions to either Pakistan or India.  This increased geopolitical tensions in the Punjab/Kashmir area with its already disputed borders.  Since the 1960 treaty, agriculture has increased bringing with it large plantations which are connected politically in high places.  Runoff of fertilizers and pesticides often gets into the drinking water that the poor must use.  In China the Three Gorges Dam on the Yangzi River created a reservoir over 400 miles long, but it required the relocation of 1.2 million people, and resulted in the destruction of hundreds of villages.  In India another grandiose plan of linking 37 rivers by constructing nearly 10,000 miles of canals is under consideration.  Public policy in water management can be hamstrung by ownership, price, and political priorities.  Ownership in the U.S. is complicated by two offsetting systems:  the riparian one in the East that gives ownership to those nearby a water source, and the prior-appropriation one in the West that gives ownership to the earliest users.  Most water utilities are state supported and operate at a loss as the consumers are charged a price lower than the overall cost.  The consumers that need public policy support the most are those that have unfit or unsafe drinking water.  However, this political interest group ordinarily has less clout in lobbying the appropriate governments for relief.

Conclusions:  Good management is the best approach to water conservation, and conservation is still the all-around best way to retain enough water to meet the earth’s needs and protect the environment from over usage and pollution.  In arid regions of the world, agriculture should focus on producing those products that require less water.  The obverse would apply to those regions of the world that have surpluses of fresh water.  The equalizer would then be trade between and among these regions.  Distribution is the key, and water system infrastructure is required to gather, store, clean, and then release water to the using public, including agriculture.

Sources:          Thirsty Planet, The Economist, March 2^nd, 2019.

                        The Looming Crisis over Water by Alice Albinia, National Geographic, July, 2020.