Sustainable Water Supplies

As the number of people who need access to clean water rises with population growth, sustainable water supplies are essential to meet those demands. There are many strategies to try and increase water supply through infrastructures like dams and reservoirs; however, these constructions can affect the surrounding ecosystems and release carbon dioxide. Let's look into sustainable ways of supplying water.

Sustainable water supplies definition

First of all, what are water supplies? Water supplies are water provided for you daily. These could be tunnels and pipelines through the government, private companies, communities or individuals.

As mentioned before, with the increase in demand for clean water and the predicted continued population growth, water supplies need to be sustainable.

Water supplies sustainability issues

If we look into how we try to increase the supply of water, there are some pros and cons of those strategies. Many of the cons are problems with how the strategy affects the environment negatively and is hard to sustain.

Dams and reservoirs

Dams are usually constructed in naturally formed valleys across a river or stream to hold back the water. As a result of a dam, the water collects and creates an artificial lake which is a reservoir. Dams can control the flow of water and stop flooding occur downstream. Hydroelectric power can be generated with the dam from the energy of the water levels falling. However, land which may house people and animals is lost to create space for the reservoir. Reservoirs can also lose water if they are situated in a hot climate as the water evaporates and cannot collect.

Fig. 1 The Three Gorges, China

Underground storage

Underground storage is usually used in countries with a hot climate where water evaporates quickly. It is when water is pumped underground to be stored in aquifers.

Underground storage can be used to supply water to houses in hot climates and can be used to provide water when there is not much rainfall. The downside of underground storage is that they are expensive to construct and run continuously. Another problem is the effect on the surrounding environment when the water is forced underground. This could cause tremors and disturb the ground, affecting nearby people and the ecosystem.

Water transfer schemes

Water transfer schemes transport water from a place with a water surplus to a place with a water deficit.

Water transfer schemes take water from water sources like reservoirs where the water collects and uses canals and pipes to transport the water to rivers and reservoirs in other parts of the country or other countries. This could be to supply large cities that don't have enough space for reservoirs. Also, water is a resource that can be profitable, so transferring and trading it can be useful for the country through water transfer schemes. However, water transfer schemes are not for everybody as they usually need funding support to construct because infrastructures such as canals and pipelines are expensive. Another hurdle is that water transfers can lead to water loss due to leakages in the pipelines if they are not well maintained.

Fig. 2 Katse Dam in Lesotho

Desalination

Desalination is when reverse osmosis is used to turn salt water into fresh water.

Through desalination, places near the coast that don't have much access to fresh water stores can have fresh water. However, desalination uses a lot of energy, and it is costly. Also, the waste brine can be harmful to the environment when pumped back into the sea.

Importance of sustainable water management with sustainable water supplies

It is not just how we supply water that should be sustainable. There are ways to make both water supplies and water management sustainable too. This can be done in a number of ways.

Examples of sustainable water management are learning to conserve water, living in a way that could reduce water usage, and encouraging less water usage. Other methods could also be to recycle water and focus on groundwater management.

Sustainable water supply strategies and examples

Here are a few examples that show how sustainable water management and sustainable water supplies work together.

Groundwater management

Groundwater management is the management of water pumps through laws to stop the over-extraction of the aquifers. This can reduce the risk of the water being used up too quickly that it cannot be replaced naturally. It also reduces the risk of the water levels dropping too low, which can lead to contamination of salt or pollution. There are still cases of people extracting water illegally despite laws, and limiting the number of pumps can result in people selling water for more than people can afford.

Recycling

Recycling treated domestic and industrial water by using it in cooling plants helps save on freshwater that can be used in a daily situation. Sewage can also be used in agriculture and farming. In the case of fish farming, sewage can help algae to grow and fish to thrive, which increases yield. However, some industries don't take this approach as treating water can be more expensive.

Water conservation

Water conservation is to focus on the social aspect of how to use less water daily. This could be on the scale of water companies checking that the pipes and waterways are in good condition, so there are no leakages and waste of water and on the scale of turning off the water whilst brushing your teeth. Water conservation could be encouraging less water usage as well.

Fig. 3 Water conservation message in Cape Town