Managing water supplies will require action at a variety of levels. Likely actions include:
- Hard engineering projects to increase water storage and transfer.
- Restoration of lost water supplies.
- Water conservation in urban areas, such as rainwater harvesting and water recycling.
case study: the three gorges project
- Project along the Yangtze river and the world’s largest hydroelectric scheme.
| Benefits | Costs |
| · 18,000MW of electricity generated could save 50 million tonnes of coal each year
· Supply water to a region responsible for 22% of China’s GDP · Flood protection could save lives and cut financial losses from flood damage · Navigational improvement could help open up interior region of China to development |
· Dammed waters will drown 100,000 hectares of arable land, 13 cities, many smaller settlements and 1,500 factories
· 1.9 million people will be displaced · Dam failure, earthquakes, heavy rains and terrorism pose safety risks · Fisheries, biodiversity and habitats will be disrupted · Pollution will increase as mines and factories are flooded · Important archaeological and habitat sites lost · River has the world’s largest sediment load. Sediment could damage turbines and become trapped behind dam, raising water levels and reducing soil fertility downstream. |
hard engineering
Limited to developing countries
Costs are between $22 and $31 billion each year
Half the world’s large dams were built for irrigation, contributing up to 16% of world food production
Benefits:
- HEP
- Flood control
- Domestic water supply
Costs:
- Economic costs – construction of large dams seems to overrun projected costs by an average of 50%. Water sales rarely cover costs of water supply in developing countries. The total global investment in dams between 1950 to 2000 was approx. $146 billion
- Ecological costs – dams have fragmented 6% of the world’s rivers, disrupting floodplain agriculture, fisheries, pasture, forestry and ecosystems.
- Social costs – during construction phase, local communities are staved of development and welfare investment. Their livelihoods are severely disrupted. Constructions of dams in Chindia have displaced 58 million in the last four decades.
river, lake and wetland restoration
At a local scale this can involve restoring meanders, replanting vegetation and using sustainable methods to manage watercourses for people and the environment.
case study: restoring the aral sea
In 2007 the Kazakhstan government secured a $126 million loan from the World Bank to help save the northern part of the Aral Sea. The government has already built a dam to split the sea into 2 parts and the new loan is to be used to build a dam to bring the water back into the deserted port of Aralsk.
- Northern sea is already filling up.
- Fisherman have been able to resume fishing.
- Rain has returned.
- The southern part of the sea is still shrinking.
- Many experts believe it is too late to save it.
- The waters of the Amu Darya which should on feeding into the sea is needed for growing cotton as the economy of Uzbekistan is heavily dependent on it.
- The waters from the Amu Darya and Syr Darya are controlled by other countries.
- Developments could trigger conflict.
Water conservation
- This involves reducing the amount of water used.
- In agriculture it can be efficient irrigation.
- In industry water can be treated for recycling.
- Conserve wetlands.
- Rising water prices and introducing water meters.
- Modern spray technology.
- Drip irrigation, expensive, but effective.
- Fertigation, using small amounts of fertiliser with fine water sprinklers, has been effective in Israel and the USA.
In the UK around 22% of water does not reach the end user due to leakage. Examples include:
Reducing domestic consumption.
- Installing water meters in every home.
- Reducing the amount of water used in lavatory cisterns.
- Planting drought resistant species in ‘water-wise’ gardens.
- Using grey water to flush the lavatory or water the garden.
Reducing industry consumption
- installing more efficient systems to reduce water costs
- Agricultural irrigation resulting in the use of micro-irrigation techniques using drip irrigation from tubes reduces the volume of water used.
WaterAid projects in ETHIOPIA
Mobile toilet and kiosk:
- Provide income, saves people money.
- Keeps area clean.
- Offers job opportunities.
Spring-fed wells:
- Ensures clean water supplies for families.
- Reduces chance of waterborne illness and deaths.
- No time wasted going to health clinics.
- Saves time and money.
- Money can be used to improve standard of living.
Education about hygiene:
- Teach people about sanitation and hygiene.
- Teach how to construct latrines from local materials.
- This prevents drinking water becoming contaminated with faeces.