Water is essential to life everywhere. Despite the necessity of water, the natural systems that allow water to be cleaned, maintained, and distributed are fragile and sensitive to changes. And because water is so integral to so many other natural processes, disruptions in water systems have rippling effects that filter through to all aspects of life. Sustaining water systems requires not only preserving and improving water quality, but also creating ways to use water that doesn’t disrupt its natural processes.
Agricultural pollution
Agriculture has long-term effects not only on the land on which it takes place, but on the surrounding environment too. The same fertilizers that allow crops to grow and flourish also leach into nearby water and air systems. What is good for crop growth is often bad for the natural world. Nitrogen and phosphorus are damaging to aquatic life in large quantities, and can create eutrophication, where algae overgrows in a body of water and stifles oxygen production and, consequently, aquatic animal life. Runoff from animal agriculture can contaminate water with animal waste and antibiotics that make water undrinkable. Agricultural pollution often spreads far beyond its point of origin and can be dispersed to entire water systems, making this type of pollution particularly difficult to combat once runoff has already happened. With the population growing worldwide and the amount of land used for farming on the decline, pressure to make agriculture more productive will likely increase the amount of fertilizers used.
Aquifer depletion
Aquifers are geologic structures that allow groundwater to accumulate beneath the surface of the earth. Over 2 billion people all over the world use groundwater as their primary source of water. Even in areas with abundant surface water, groundwater is critically important to the irrigation systems that drive agriculture. Aquifers all over the world have grown increasingly stressed as more and more water is withdrawn for agricultural, industrial and residential use. As water levels decline, groundwater becomes more susceptible to contamination from both pollutants and saltwater, streams and rivers lose a key replenishing source, and soil deteriorates in quality and structure. As more and more communities face droughts and other water shortages, the depletion of aquifers is beginning to have a bigger impact on global water supplies. A quarter of the world’s population lives in areas with “extremely high” aquifer stress, and that number will increase in coming years.
Sanitation infrastructure
Sanitation involves safely managing human waste so it can be properly treated and disposed of without entering water systems or coming into contact with human populations. Over two billion people worldwide lack access to improved sanitation infrastructure, which the World Health Organization defines as “sanitation facilities that hygienically separate human excreta from human contact.” Where sanitation is improperly managed, it is a major contributing factor to the spread of infectious diseases such as dysentery and typhoid, which infect millions of people every year. Children are particularly vulnerable to diseases spread by improper sanitation: nearly 400,000 children die every year from diarrhea.
Rising consumption is tied to an increasing amount of all kinds of waste. Food is wasted by both producers and consumers; hazardous waste is produced by industry and manufacturing; e-waste is created by discarded electronics including computers, phones and batteries. Disposing of waste poses a number of challenges for communities. Landfills produce toxic gases and leach chemicals into water systems. Industrialization and urbanization often outpace the development of waste management systems. Waste finds its way into natural environments, including rivers and oceans. Waste production is poised to dramatically increase in the coming decades, making better infrastructure for waste disposal even more critical than it already is.
Modifying waterways (dams, levees)
Waterways are diverted and changed for any number of reasons, including to generate power, accumulate fresh water, and allow for construction on surrounding land. Though modifications like dams and levees may have immediate practical applications, they create long-term consequences. Modified waterways make surrounding areas more susceptible to flooding by changing the natural systems that help absorb water. They disrupt the filtration processes that help keep contaminants out of lakes and rivers. They destroy the ecosystems that help local animal and plant life survive in their natural habitats. They make communities more vulnerable to natural disasters like hurricanes. While modifying waterways can be unavoidable, and is in some place irreversible, concerns about their fundamental change to water systems are often not accounted for until problems have made themselves apparent.
Safe drinking water
Hundreds of millions of people worldwide lack access to even basic drinking water, and more than two billion people rely on water sources that are contaminated with human waste. At the same time, drinking water systems are being depleted at a rate faster than they are replenished, and in the next ten years, half of the global population will be relying on stressed sources for their drinking water. Communities all around the world are already getting a glimpse of the future: in the Indian city of Chennai a drought has decimated the city’s water supplies and left millions of people with no drinking water. Superior water management, planning, and infrastructure all help to make water crises more manageable, but cannot fix the fundamental environmental problems that make drinking water a problem worldwide.
Sanitation infrastructure is difficult to improve for a number of reasons, including cost and stigma. Sanitation has greatly improved in recent years, with diarrheal diseases no longer one of the top five causes of death worldwide, but billions of people are still at risk from lack of sanitation infrastructure.
