Water Uses, Planning, and Conservation Strategies
Water Uses
Consumptive Uses
- Industry: Raw material for chemical synthesis, refrigeration, steel production, waste transport, cleaning, and steam generation for electricity.
Non-Consumptive Uses
- Energy: Hydroelectric power generation.
- Recreation: Sports and leisure in rivers, reservoirs, lakes, and the sea. Includes primary contact (baths, spas) and secondary contact (landscape, navigation).
- Ecological and Environmental: Wetlands and lagoons as habitats for plants and animals, havens for migrating birds, and home to endemic species.
Water Planning
Water is an essential, limited, and scarce natural resource. Effective water planning involves measures to enable savings, rationalize consumption, and limit pollutant emissions. These actions must be supported by technical measures to find new water resources and improve the utilization of existing ones.
Rationalization Measures for Saving and Consumption
1. General Measures
- Protection of all rivers, streams, and aquifers from contamination.
- Encourage water recycling to multiply its uses and reduce extraction from nature.
- Protection of forests. Forests slow down water movement in the hydrologic cycle, retain water, increase humidity, and favor rainfall.
- Adjust the exploitation of old and non-renewable deep aquifers, which is currently reckless for urban use and irrigation. Overexploitation near the coast leads to salinization.
2. Saving Measures for Industrial Applications
- Agriculture: Crucial to reduce irrigation consumption in rainfed areas. Most current irrigation systems are wasteful and need replacing.
- Industry: Industrial areas consume and contaminate large quantities of water. Industrial pollutants are often non-biodegradable, causing pollution by heavy metals and synthetics. CO2 emissions negatively affect the water cycle.
3. Technical Measures
- Reservoirs: Construction of dams and reservoirs to regulate river waters, control floods, supply water, generate energy, and provide leisure opportunities.
- Transfers: Exporting water from surplus to deficit river basins through channel systems, with high environmental and landscape impact.
- Action on the courses of rivers: Restore damage (loss of drainage capacity, water quality). Facilitate water movement, remove silting, clean channels, and revegetate with riparian forests.
- Desalination of seawater (or brackish): Obtain potable water by separating dissolved salts. Includes:
- a) Thermal Processes: Evaporation of saline water and condensation into fresh water.
- b) Membrane filtration procedures: Reverse osmosis, a high-pressure mechanism that reverses the natural osmosis process.
4. Political Solutions
Enactment of laws governing water use and management, and international conferences to address water scarcity:
- Conference of Nations Water (Mar del Plata, 1977): First global water assessment.
- Rio de Janeiro (1992): Evaluation of water resources, emphasizing the need for constant monitoring of sources, quantity, and quality.
- The Johannesburg Summit (2002): Emphasized the need to promote water availability in countries facing scarcity.