Water Management: Sustainability, Pollution, and Solutions

Sustainability and Water Use

If we use water faster than it can be replenished, its use is not sustainable. We need to store and distribute it efficiently, which can be expensive.

Large-Scale Water Management Projects

Large-scale projects to increase water supply often involve big dams. They are usually complex, multi-purpose projects. Up to the 1980s, the rate of building increased until most of the best sites in North America and Europe had been developed, in the so-called 'Blue Revolution'.

Currently, dams supply:

• 40% of the world's irrigated water.
• 20% of the world's electricity.
• 15% of all blue water.

Dams may bring benefits in terms of increased water supply, but they can have negative impacts too. Their construction can disrupt fragile aquatic ecosystems, destroying fisheries and wildlife. Around 45,000 large dams worldwide affect 6 out of 10 major rivers and have caused about 80 million people to be forcibly relocated.

Social, Economic, and Environmental Impacts of Dams

SOCIAL advantages: scenic amenity, recreational use, floods are controlled. ECONOMIC advantages: fish stocking, hydroelectric power attracts industry. disadvantages: loss of farmland and villages, dam interferes with logging, navigation, and fish migration, less sediment means more energy, leading to ''clear water'' erosion. ENVIRONMENTAL advantages: habitat for water birds, increase in humidity, water for domestic use and irrigation, regulated flow. disadvantages: can reduce water quality, sedimentation in lake, dam acts as a knickpoint, energy is reduced and deposition results.

Pollution in Developed Economies

Developed countries have taken big steps to control pollution. Their economies are heavily based on tertiary and quaternary activities, which cause less water pollution than primary and secondary industries.

In the 1960s, pollution caused major health problems and damaged ecosystems. In the 1970s, the government produced standards to improve water quality and tackle pollution.

Small-Scale Sustainable Solutions

Non-governmental organisations (NGOs) often develop small-scale sustainable solutions to local problems in developing countries. Local communities are involved in projects to develop safe and reliable water supplies. NGOs set up low-cost projects using appropriate or intermediate technology that is appropriate to the geographical conditions of the local area and within the technical ability of the local community so that they can operate and maintain it themselves. Local people are trained to take responsibility for the development and management of the schemes. The schemes include rainwater harvesting, protecting springs from contamination, developing gravity-fed piped schemes, and building hand-dug or tube wells (which are built where the water table is too deep to be reached by a hand-dug well) for villages.

Many of the NGO projects are in rural areas, but others are in urban areas, helping with sanitation problems, which will prevent water supply contamination.

Pollution in Emerging and Developing Economies

Levels of water pollution can be related to economic development. The highest levels of water pollution are usually linked to the most rapid rates of economic growth. These countries are industrialising and developing their energy sources rapidly. They tend to put economic growth before environmental protection. Very rapid urban growth means cities are growing faster than the infrastructure for piped water and waste disposal systems can be installed. As a result, streams flowing through the slums and shanty towns of megacities are badly affected by pollution. Many countries are also developing commercial agriculture, and runoff of chemicals increases water pollution. Developing countries generally lack the concentrations of industry found in more-developed countries. People live and work in rural areas. Pollution exists, but it tends to be less concentrated.