Managing Water Supply (Edexcel A Level Geography)

Hard Engineering to Increase Water Supply

• There are conflicting views over what is the best approach to managing water supplies

• Economic stakeholders prefer hard-engineered schemes, and environmental stakeholders a more natural and sustainable approach

Hard-engineered schemes

• These need capital, technology and long-term maintenance to be successful

• Schemes include:

  • Water transfer schemes

  • Mega dams

  • Desalination plants

Water transfer schemes

• These attempt to make up for water deficits through constructing systems of canals, pipes, and dredging over long distances to transfer water from a drainage basin of surplus supplies to areas of deficit

• The Kielder reservoir in Northumberland supplies water to the cities of Newcastle-upon-Tyne, Sunderland, Durham, Darlington and Middlesbrough via a water transfer

China’s south-north water transfer

• One of the largest water transfer projects in the world

• Planning began in 1952, with work starting in 2002, and is expected to be completed by 2050

• It aims im is to divert 45bnm³ of water a year from surplus river basins in the south and east to the north where there is frequent water deficits in places such as Beijing and Tianjin

• The project will cost US$62 billion to complete and will involve the resettlement of people which is not popular

• The 3 main diverting routes:

  • Western route - started in 2010, through difficult, high-altitude terrain. As the route will pass high industrial activity, it is feared that water will become polluted on transfer, as well as reduce the volumes in the Yangtze,  causing issues with sediment and the ecosystem 

  • Central route - this is a 1267km diversion with some of the water from the Three Gorges Dam being used in order help

  • Eastern route - this route is 1,155km long diversion from the Yangtze river next to Shanghai to Beijing and Tianjin in the north

• The main stakeholders are the government sponsored ‘South to North’ Water Transfer Project Company and corporate civil engineering companies building 3 major canals, pipelines, tunnels and pumping stations
  

Mega dams

• Dams block rivers so that reservoirs of water build up behind, rather than drain away

• Dams provide large, reliable supplies of drinking water and reduces water insecurity, especially in areas of seasonal precipitation 

• Dams and reservoirs can also prevent flooding, as the flow of the river is controlled, and can generate electricity through hydroelectric power (HEP)

• Nearly 60% of the world's major rivers have large dams of which the Aswan, Hoover and 3 Gorges are amongst the largest

• Although thought of as environmentally friendly, mega dams have issues aside of the huge economical costs of construction

  • Dams alter ecosystems - downstream ecosystems rely on water and sediment, both of which are held back by big dams, making downstream land less fertile

  • Dams displace people, communities and destroy cultural heritage

  • Flooding of the reservoir submerges land and destroys plants and animals

  • Dams reduce water quality and waste water - large surface areas of reservoirs increase rates of evapotranspiration and trap sediment and agricultural runoff, increasing rates of eutrophication and vector diseases

Desalination plants

• Extracts the salt from seawater to enable it to be used for drinking and irrigation

• Expensive, salt waste can damage marine ecosystems and the process uses large amounts of energy

• As the price of freshwater increases, some countries will look to the sea for water supplies

• Dubai has already done this, as has Kuwait and Saudi Arabia

• Alicante II Seawater plant in Spain and Tampa Bay Water plant, USA 

• Although it is a sustainable process, it is considered a hard engineered process due to the inputs of technology and energy and it has an ecological impact on marine life

Sustainable Schemes of Water Supply & Water Conservation

• Sustainable water management aims to:

  • Minimise wastage and pollution

  • Provide access to safe, potable water at an affordable price to all

  • Consider the views of all stakeholders

  • Guarantee equitable distribution of water between and within countries

• Action includes:

  • Smart irrigation - replace traditional irrigation methods of sprinklers and surface flows with automated spray technology and drip irrigation systems

  • Rainwater harvesting - precipitation is collected from roofs and stored in water butts for repurposing in toilets and watering gardens

  • Restoration of damaged lakes, rivers and wetlands to return them to their part in the natural water system

  • Filtration - sophisticated systems are used to remove even the finest particulates from dirty water, rendering it safe to drink again

  • Recycle - grey water is a low cost option for use domestically and in agriculture (irrigation, flushing toilets etc.) not drinking 

  • Hydroponics - crops are grown in shallow trays that are drip fed nutrients and water, there is no soil involved

Singapore

• Singapore has very little natural water resources and have made water management one of its priorities for its 6 million residents

• Based on 3 key ideas:

  • Collect all water - government educates its citizens on using water carefully and since 2003, domestic water consumption has fallen by 24 litres per person per day (24 x 6 = 144 million litres per day is a lot of water)

  • Re-use water - Singapore has cutting edge technology to re-use its grey-water called NEWater

  • Desalinate - Singapore now has 5 desalination plants meeting up to 25% of demand

Integrated Drainage Basin Management

• According to Integrated Water Resources Management (IWRM), Global Water Partnership Technical Advisory Committee 2000

• It aims to treat a river basin holistically to ensure 3 things:

  • Water is used to maximum efficiency

  • Equitable distribution

  • Conserve the environmental quality of rivers and its catchments

• IWRM is successful at a local, community level, but not at national or international levels

Water sharing treaties and frameworks

• UN Economic Commission for Europe (UNECE) - the convention promotes joint management and conservation of all shared freshwater ecosystems

• UN Water Courses Convention - offers guidelines for protection and use of transboundary rivers like the Nile

• EU Water Framework Directive (2000) - committed all members to ensure their 'status' of water bodies, which included marine waters up to 1 nautical mile offshore

• Helsinki (1966) and Berlin (2004) Rules - ensure that all have an 'equitable use' and 'equitable shares' concept

• The Water Convention and the Protocol on Water and Health - jointly serviced by UNECE and WHO-Europe, it is a unique legally binding framework that aims to protect human health through improved water management and reduction of water-related diseases. The Protocol provides a practical advice on how to provide the human rights to water and sanitation

• With the increasing risks of climate change, there is the potential for water wars to be global, despite the degrees of international cooperation at present

• Proper management of current water supplies are crucial and binding international agreements need to be in place for a sustainable water supply for future generations