Different approaches to managing water supply (Edexcel A-Level Geography): Revision Notes

Different approaches to managing water supply

Because of the diversity of players involved in the use of water resources, inevitably there are conflicting views as to what constitutes the best approach to the management of these resources.

• Many solutions to water insecurity are dependent on reducing water consumption, such as farmers storing rainwater to use for irrigation and greywater
• There has also been an increase in HEP and the generation of energy without freshwater Other solutions include hard engineering options, which economic players tend to favour over the sustainable solutions promoted by environmental players.

Tecno-Fixing of Hard Engineering

Water Transfer Schemes

Diversion of water from one drainage basin to another, either by diversion of the river or construction of a large canal to carry water from an area of surplus to one of deficit

Pros

Cons

● Availability of water simply leads to greater use ● More water available in the receiving area ● ↑ the amount of irrigation and agricultural productivity ● May deal with issues arising from climate change ● ↑ use for development eg. golf courses

● Many environmental and social disadvantages ● Continued use of transferred water may lead to long-term changes to local and regional hydrological conditions ○ Can ↑ flood risk ○ Damage to food stock ● Promotes unsustainable irrigated farming by agri-businesses ● Source area loses a large proportion of its water ● The source river has a lower flow, and the impact of pollution within it ↑ ○ Eutrophication, salination and ecosystem destruction ● Can create water scarcity in the source region ● Large carbon footprint

Mega Dams

Large dams across a river, where there are deep ganges or valleys trap water in a large reservoir; a new water store is created for local and regional use but natural river flows are altered

Pros	Cons
● Can hold back huge amounts of water ● Can be multipurpose • to store water, provide irrigation and enable power generation ● Can have a direct positive impact on the living standards of locals ● Seen as a means of combating climate change through renewable power generation ● They create a surface store providing large volumes of water, so the need to abstract groundwater is reduced	● Initial capital costs are immense so can only be afforded by developed countries or with help from FDI ● High evaporation losses ● Disrupts the downstream movement of silt, and interferes with natural processes ● Often involve the displacement of large numbers of often poor people ● Nearly 60% of the world's major rivers are impeded by these, including the Colorado and Nile.

Desalination Plants

Taking seawater and separating the water from the salts: The ocean is the world's main store of water ∴ will not run out. Eg. Egypt

Pros	Cons
● Salty water is in very high supply ● Recent technological advances have developed the reverse osmosis process and pioneering work on carbon nanotube membranes which will increase the scale of operations	● The process requires a lot of energy and so is expensive ● Produces wastewater that requires safe disposal ● Emit high levels of CO2 if they are not solar-powered

The Role of Sustainable Solutions to Management of Water Supply

Sustainable water management → Use the sustainability quadrant to focus on water management

↳ World's nations, communities and peoples, clean, safe water should be available, accessible and affordable (3 As) Sustainability of water

• Environmental sustainability is a major issue
• Many of the world's rivers are ecologically threatened as a result of human actions, which have polluted and damaged water supplies
• The water is of poor quality and acts as a vector for water borne diseases
• Nearly 25% of the world's people lack access to safe water, so environmental sustainability protects water quality
• Economic sustainability involves guaranteeing security of access to water for all groups at an affordable price
• Many schemes to manage rivers, such as mega dams, actually dispossess people of their land, homes & livelihoods
• Privatised schemes to bring clean, safe water to millions often fail to deliver at affordable rates
• Economic sustainability is also achieved by minimising wastage and maximising wastage and maximising efficiency of usage, in irrigation
• Socio-cultural sustainability manages water supplies in such a way that it takes into account the views of all users, inc the poor and disadvantaged and leads to equitable distribution within and between countries

Water Conservation

Smart irrigation involves giving crops just under the amount of water that they normally need during growth, or using efficient methods such as drip irrigation

Restoration of Water Supplies

Restoring or enhancing the natural hydrological cycle in a local area

↳ Restoring damaged wetlands, lakes and rivers to increase natural storage; restoring meanders, replanting vegetation, conserving forests and use of permeable tarmac etc. to regulate flows and improve percolation to groundwater stores

Water Recycling

Involved collecting grey water and using it for non-drinking, washing or food preparation purposes such as flushing water or treating it to make it safe to drink

↳ Grey water → Refers to waste bath, sink or washing water. It can be recycled, resulting in savings in water usage

Integrated Water Resource Management [IWRM]

↳ A process which promotes the coordinated development and management of water, land and related resources to maximise economic & social welfare in an equitable manner w/out compromising the sustainability of vital ecosystems

• Integrated drainage basin management (IDBM) regards the drainage basin as the basic unit of water management
• Based on achieving close cooperation between users and managers within a basin
• Aims are to maintain
  • Environmental quality
  • The efficient use of water resources
  • An equitable distribution of those resources
• It may work within countries, but trans-boundary issues may prove more difficult - often sparked by 'greedy' upstream behaviours
• Treats the river basin holistically to ensure environmental quality, maximum efficiency of water use and equitable distribution amongst users

Features of the IWRM

• Freedom from corruption
• Environmental protection of all supplies, ecosystems
• Food and water security for the poor
• Effective dialogues between users and providers
• Good governance w/ decentralisation of decision making often linked to national strategies
• Appropriate choices regarding water use in economic productivity
• Effective regulation and planning of use
• Cash recovery of schemes via effective pricing The process of IWRM

Important international agreements enabling IDBM include:

• Helsinki Rules agreement on 'equitable use' and 'equitable shares' Criteria for water sharing should be based on:
  • Natural factors → Rainfall amounts, discharge along water sources, share of drainage basin, impact of climate change
  • Social & economic needs → Population size, welfare of people, development plans
  • Downstream impacts → Restructuring flow, lowering water tables, pollution
  • Dependency → Availability of alternative sources
  • Prior use → The tricky question of existing historic rights or potential future use
  • Efficiency → Avoiding waste and mismanagement of water
• The UNECE water convention, which promotes the joints management and conservation of shared European freshwater ecosystems
• The UN Watercourses Convention - Seeks to protect and regulate use of trans-boundary rivers
• The EU Water Framework Directive Commits members to ensuring the status of their water bodies, inc marine waters up to one nautical mile from their shore
• The EU Hydropower Directive - Regulates energy production within member states But most agreements lack appropriate enforcement and monitoring. The key players involved in water management are the UN, EU and national governments.

Helsinki Rules - agreement on 'equitable use' and 'equitable shares' - Sharing of water

• Natural factors
• Social & economic needs
• Efficiency

Integrated Water Resource Management

↳ A process which promotes the coordinated development and management of water, land and related resources to maximise economic & social welfare in an equitable manner w/out compromising the sustainability of vital ecosystems

• Integrated drainage basin management (IDBM) regards the drainage basin as the basic unit of water management
• Based on achieving close cooperation between users and managers within a basin