Water Resources: Management, Conservation, and Sustainable Use

Water Resources: A Vital and Limited Resource

Water is a dominant factor for the development of life. It is a limited resource, since the available quantity is conditioned by its unequal distribution in space and time. Nearly two billion people live in countries facing water stress. The problems presented with respect to water as a resource are the increase in consumption and scarcity. Agricultural practices, industrial and urban activities, as well as the increase of population and improvement in the quality of life in society, increase water requirements.

Solutions for Sustainable Water Use

• Improving efficiency in water use
• Sharing available water in solidarity
• Introducing new technologies in industries
• Implementing water policies based on efficiency, savings, reuse, and recycling of water

The Water Cycle

Ocean water evaporates, forming water vapor. This vapor enters continents and leaves as liquid water (rain).

Human Influence on the Hydrologic Cycle

Available water destined to meet the needs of human beings is located in the liquid state on continents. To provide greater quantities of fresh water and to achieve greater efficiency, the following are employed:

• Construction of dams and reservoirs
• Control of exploitation of aquifers and artificial recharge
• Harvesting dew water
• Water transfers
• Desalination

Future solutions may include the coverage of dams and the generation of artificial rain.

Uses of Water

• Urban: Covering household needs, trade, or public services
• Industry: Cooling, raw materials, discharge receptor
• Agricultural: Irrigation
• Energy: Cooling in nuclear power plants and electricity generation
• Navigation and recreation
• Ecological uses: Maintaining the equilibrium of aquatic ecosystems and conserving biodiversity

Water Demand and Management

Water demand is the quantity of water that users require to meet their needs. Extraction is the amount of water displaced from a natural resource. Supply is the amount of water extracted for users. Use is the supply that is used effectively.

Hydrological planning is the ordination of the intended uses of water, increasing the efficiency of these uses and contributing technical solutions where there are no other possibilities to meet the demands.

Reducing Water Consumption

In Agriculture

• Changes in irrigation
• Improvement in water management practices
• Reuse of purified wastewater for irrigation

In Urban Areas

• Use of low-energy facilities
• Adoption of water pricing
• Application of aeration in landscaping
• Urban planning
• Reuse of domestic sewage
• Environmental education

Technical Solutions

• Construction of dams
• Diversions
• Action on the courses of rivers
• Desalination of seawater or saline water

Desalination: Membrane Filtration

A procedure using membrane filtration is a mechanism of high pressure. The separation of water and salt is accomplished through semi-permeable membranes that allow the passage of water, obtaining desalinated water.

Osmosis

Osmosis is the exchange of water through permeable membranes, from the medium with lower salt concentration to the one with higher concentration.

Water Resources in Spain and Their Management

Water is a national asset, a resource so scarce that it requires water policy planning. The central administration is responsible for the problems of quantity and quality of water. It is responsible for drafting the National Water Plan. The National Water Council is an advisory body, and other organs may suggest lines of technological research to conserve and restore water-saving measures.

Basin River Basin organizations were created in 1926 as management agencies. In 1991, a new organization called the General Direction of Water Quality was created, which seeks to preserve and restore the quality of the water environment.

Hydrological Planning in Spain

Hydrological planning in Spain stresses the following objectives:

• Increasing the availability of water
• Protecting water quality
• Rationalizing water uses to meet the water demands of the Spanish population

National Hydrological Plan

Among its objectives are to achieve good public water and bodies of water, managing water supply and meeting the present water demands. To achieve its goals, the coordination of the various river basin management plans proposes measures such as desalination of seawater, reuse and wastewater treatment, rainwater pipes, replacement, and artificial groundwater recharge.

Landscape

Landscape is a combination of the highlights, the living, water, and man-made constructions.