At this time, the western United States is facing a historic drought which is impacting aquifers and waterways.
Indiana Department of Environmental Management (IDEM)
Society for Freshwater Science
Water serves many purposes for humans and for the environment. Some of these purposes conflict with each other.
Some water needs to remain in the environment to maintain ecosystem health. Animals and plants in and around the river need water for health; therefore, the water must be kept of sufficient quality and cleaniliness. Enough water must remain in and on the ground to maintain the moisture levels of the soil and the depths of rivers, lakes, and streams. Water is used for recreation, such as boating, swimming, and waterskiing. Water is used for transportation. Barges float on water to carry heavy cargo and the water must be of sufficient depth to allow this. Barges may shed pollutants in the process. Water is used for energy for powerplants and sufficient water must be present to flow and generate power.
Some water is removed from the environment. Humans use water for drinking, washing, cleaning, cooking, and growing food. Rivers and lakes are used as reservoirs for urban and rural societies. Rural areas more often use wells to extract groundwater for houses and towns. Water is used to hydrate livestock, irrigate crops and other environments. Water is used to irrigate desert areas. Drainage from some lands carries fertilizer, salt, and pollutants back into the waterways. Water is used for heating and cooling. It is used in the manufacturing of many products.
To maintain an appropriate and sustainable balance, natural water systems must be monitored and studied.
In 2000, world leaders met at the United Nations Headquarters to adopt the United Nations Millennium Declaration, committing their nations to reduce extreme poverty and set out the Millennium Development Goals with a deadline of 2015.
Among the goals and resolutions, they recognized and resolved
19. We resolve further:
• To halve, by the year 2015, the proportion of the world’s people whose income is less than one dollar a day and the proportion of people who suffer from hunger and, by the same date, to halve the proportion of people who are unable to reach or to afford safe drinking water.
23. We resolve therefore to adopt in all our environmental actions a new ethic of conservation and stewardship and, as first steps, we resolve:
• To stop the unsustainable exploitation of water resources by developing water management strategies at the regional, national and local levels, which promote both equitable access and adequate supplies.
Take note that these goals focus on the use of water by humans, although they do not discount the importance of water to the environment itself.
Freshwater Biology journal