Water is a commodity that we use in day to day life but don’t always consider as a limited resource. It is vital for our health and wellbeing, we use it in agriculture, fisheries, industry and transportation and it is necessary for a high-quality natural environment. Here in the UK, we take for granted that water will always be there to the quality that we require. We switch on our taps at home and water always comes out clean and fresh. But these water resources are seeing increasing pressures. Recent droughts in 2004-2006 and 2010-2012 and the floods in 2007 and 2014 have brought into sharp focus the pressures that climate change will bring. Due to comparatively low rainfall and high per capita water consumption, combined with future projections for rainfall and demand, all south-eastern areas in the UK are classified as seriously water stressed. This is not just an issue for the UK, across the world, many other areas are facing water shortage issues, California has just entered its fourth drought year.
Increasingly people are exposed to a high risk of water pollution. This could be from increased amounts of nitrogen and phosphorous or high levels of biochemical oxygen demand (BOD). Rapid deterioration of water quality will have a huge impact on human health, economic development and aquatic ecosystems. Estimates suggest that half of the world’s population, half of global grain production and 45% of GDP could be at risk due to water stress by 2050 unless sustainable water resource management practices are adopted.
Many of the pollutants that make it into our water courses are naturally occurring, for example nitrogen and phosphorous, and are in fact necessary for healthy ecosystems. The problems happen when concentrations of these nutrients are increased beyond natural levels, for example, from agricultural runoff. One of the main consequences of this is called eutrophication, when algal growth is accelerated and depletes oxygen, producing elevated toxins and bacteria in water and killing off other aquatic life. But the impacts are not only felt in the environment, pollutants like this can make drinking water dangerous, high levels of nitrates can have harmful effects on infants and cause gastric problems in adults.
Poor water quality further reduces the amount of available water that can be used. The burdens associated with treatment make a polluted water source almost as bad as having no water source at all. However, there are a number of solutions that can go a long way to managing water resources and minimising the negative impacts. These solutions come from technology, best practices and social behaviour. We can look at more rigorous investment in waste water treatment, making sure that the water that is discharged is of sufficient quality to support the environment and not cause additional problems. It is also important to monitor and manage discharges from other industrial processes. By being informed about what is being discharged, we can better manage our environment and water sources.
As populations grow and quality of life improves, the demand for water, food and sanitation is increased, putting increased pressure on an already taxed resource. As populations explode, an increase in fresh water supplies cannot catch up. In addition to population increases, changes brought on by climate change will also affect water quality and availability. Rising temperatures, increased levels of sediments, nutrients and pollutants caused by heavy rainfall and disruption to treatment facilities during floods will all affect water resources.
As we see demand for water in terms of quality and quantity increase, we do not see a corresponding increase in water reserves. Water is vital to life and many of our day to day activities, but unless it is managed sustainably as we move into the future, we will see increasing issues to do with water shortages and unusable water reserves.