Our Use of Water
Every plant, animal, and human being needs water to stay alive. This is because all the life processes-from taking in food to getting rid of wastes-require water. But people depend on water for more than just to stay alive. We also need it for our way of life. We need water in our homes-to brush our teeth, cook food, and wash dishes. We need water in our factories-to manufacture almost everything from automobiles to zippers. We need water for irrigation-to raise crops in regions that do not get enough rain.
Household use of water :
Where there is water, there is life. Life exists around numerous uses of water which makes it important for survival and luxury. It is a part of our biosphere that should not be overused, ignored, or taken for granted. Because of this, water should be conserved to sustain our domestic needs for the future.
As world population is constantly growing, the demand of water increases each and every day. The luxuries of domestic uses of water have become a necessity to people in their homes and backyards. Domestic water is normally characterized by its use inside and outside the home: washing the dishes, cooking a meal, laundry, bathing, watering the lawn or garden, and other household activities.
In a typical home approximately 50% of water is used in the bathroom. The toilet makes up 26%, while the shower and sink use 23%. Outside of the house, 35% of water use is for lawn or garden care. Below is a picture showing more detailed information of water use inside of a home.
Agriculture use of water :
The use of water for agriculture has changed the production of crops dramatically in the 20th
century. Agricultural use of water accounts for nearly 70% of the water used throughout the world, and the majority of this water is used for irrigation. During the 1970s, the construction of irrigation systems dramatically increased. Its rate of growth began to decrease in both developed and developing countries in the 1980s. An increase in irrigation development guarantees an increase in crop production in many countries. Irrigation allows the land that does not receive enough precipitation annually to become land that can be used for productive agriculture.
On the negative side, irrigation of land causes salinization of the land that is being irrigated, mostly in arid and semi-arid regions. Irrigation of cropland can increase the possibility fertilizers and pesticides will infiltrate into the groundwater or runoff into nearby streams. Along with the irrigation of crops, the farmers that have livestock must provide clean water for the livestock to drink. With a growing world population, expected to increase by 2 billion people by the year 2030, agriculture needs to find a way to use less water or to use the water more efficiently.
There are several different systems that are used for irrigation purposes, including ditch irrigation, terracing, overhead irrigation, centre pivot irrigation, lateral move irrigation, and drip or trickle irrigation. Irrigation of cropland has greatly increased production of food, but has also had some drawbacks due to the amount of water that is being drawn from aquifers. Some of the problems with irrigation are competition for surface water rights, depletion of underground aquifers, ground subsidence, and build-up of toxic salts on soil surfaces in regions of high evaporation rates, called salinization. These problems can be increased or be more detrimental during periods of drought.
Recreation use of water :
Recreational water use is usually a very small but growing percentage of total water use. Recreational water use is mostly tied to reservoirs. If a reservoir is kept fuller than it would otherwise be for recreation, then the water retained could be categorized as recreational usage. Release of water from a few reservoirs is also timed to enhance white-water boating, which also could be considered a recreational usage. Other examples are anglers, water skiers, nature enthusiasts and swimmers.
Recreational usage is usually non-consumptive. Golf courses are often targeted as using excessive amounts of water, especially in drier regions. It is, however, unclear whether recreational irrigation (which would include private gardens) has a noticeable effect on water resources. This is largely due to the unavailability of reliable data. Additionally, many golf courses utilize either primarily or exclusively treated effluent water, which has little impact on potable water availability.
Environmental Use of Water :
Explicit environment water use is also a very small but growing percentage of total water use. Environmental water may include water stored in impoundments and released for environmental purposes (held environmental water), but more often is water retained in waterways through regulatory limits of abstraction. Environmental water usage includes watering of natural or artificial wetlands, artificial lakes intended to create wildlife habitat, fish ladders, and water releases from reservoirs timed to help fish spawn, or to restore more natural flow regimes
Like recreational usage, environmental usage is non-consumptive but may reduce the availability of water for other users at specific times and places. For example, water release from a reservoir to help fish spawn may not be available to farms upstream, and water retained in a river to maintain waterway health would not be available to water abstractors downstream.
Industrial Use of Water :
It is estimated that 22% of worldwide water is used in industry. Major industrial users include hydroelectric dams, thermoelectric power plants, which use water for cooling, ore and oil refineries, which use water in chemical processes, and manufacturing plants, which use water as a solvent. Water withdrawal can be very high for certain industries, but consumption is generally much lower than that of agriculture.
Water is used in renewable power generation. Hydroelectric power derives energy from the force of water flowing downhill, driving a turbine connected to a generator. This hydroelectricity is a low-cost, non-polluting, renewable energy source. Significantly, hydroelectric power can also be used for load following unlike most renewable energy sources which are intermittent. Ultimately, the energy in a hydroelectric power plant is supplied by the sun. Heat from the sun evaporates water, which condenses as rain in higher altitudes and flows downhill. Pumped-storage hydroelectric plants also exist, which use grid electricity to pump water uphill when demand is low, and use the stored water to produce electricity when demand is high.
Hydroelectric power plants generally require the creation of a large artificial lake. Evaporation from this lake is higher than evaporation from a river due to the larger surface area exposed to the elements, resulting in much higher water consumption. The process of driving water through the turbine and tunnels or pipes also briefly removes this water from the natural environment, creating water withdrawal. The impact of this withdrawal on wildlife varies greatly depending on the design of the power plant.
Pressurized water is used in water blasting and water jet cutters. Also, very high pressure water guns are used for precise cutting. It works very well, is relatively safe, and is not harmful to the environment. It is also used in the cooling of machinery to prevent overheating, or prevent saw blades from overheating. This is generally a very small source of water consumption relative to other uses.
Water is also used in many large scale industrial processes, such as thermoelectric power production, oil refining, fertilizer production and other chemical plant use, and natural gas extraction from shale rock. Discharge of untreated water from industrial uses is pollution. Pollution includes discharged solutes (chemical pollution) and increased water temperature (thermal pollution). Industry requires pure water for many applications and utilizes a variety of purification techniques both in water supply and discharge. Most of this pure water is generated on site, either from natural freshwater or from municipal grey water. Industrial consumption of water is generally much lower than withdrawal, due to laws requiring industrial grey water to be treated and returned to the environment. Thermoelectric power plants using cooling towers have high consumption, nearly equal to their withdrawal, as most of the withdrawn water is evaporated as part of the cooling process. The withdrawal, however, is lower than in once-through cooling systems.