Define and explain water conservation?

Before I try to respond to the question in a substantive way, I will respond with an observation: The most simply stated questions are often so broad as to require volumes to answer. Despite an effort to keep this short, I know that I will fail because water use, upon which water conservation depends, is complicated. I particularly like one definition of the word "conservation" given in the Random House Dictionary in this regard: "The careful utilization of a natural resource in order to prevent depletion." Thus, water conservation would require "careful utilization" of available water resources "in order to prevent depletion" of that water. What it means will vary, depending on the circumstances. I believe, however, that the meanings from all circumstances should be kept in mind at all times. Think about how we use water. Actual human consumption accounts for very little of what we use (even if you count all food preparation uses, cleaning of cooking utensils, and domesticated animal consumption as human consumption). (I lump these together because contaminated water in any of these uses can readily result in human disease.) We use most of what enters our homes for flushing the toilet, washing laundry, and bathing. (Bathing water does not necessarily need to be as pure as water used for drinking or food preparation, but grossly contaminated bathing water can cause human disease.) We can use even more than that to fill our pools and water our lawns. And what is used in and around our homes is only a fraction of what is used for process cooling, cleaning, etc. in industrial processes and for agricultural irrigation. The primary sources of all this water is groundwater and surface water. Whether a particular source of water can be used depends on the mineral content of the water (too high of a mineral content can make water unsuitable for drinking and other uses (e.g., salt water can be toxic for drinking; manganese, iron, and hardness in water can make it unsuitable for laundry or bathing), the amount available, the reliability of the source, seasonal or climatic variatiability in the quantity or quality of water available, and other factors, such as intended use. More water is derived from groundwater, which can be the purest and cleanest water available. Much groundwater is extracted so pure that it is suitable for immediate consumption, but some shallow wells are susceptible to contamination from surface sources, and human activities (primarily waste-related) can contribute to this contamination--even in deep wells, on occasion. Many areas rely on surface water water sources. Surface water can be easier to extract where there is a suitable stream or lake, but it is more susceptible to chemical and biological contamination from natural and human causes. Whatever the souce of water, treatment is needed for human consumptive uses. This can mean radical changes in the chemical and biological qualtiy of the water, or it could mean only adding a disinfectant to prevent contamination in the distribution system. Agricultural irrigation and industrial uses usually require no treatment, but where the system providing this water also provides water for human consumption, treatment is required. The usual treatment for a surface water would include adding a flocculant to enhance settling of many chemical and biological contaminants suspended in the water, followed by filtration to remove what did not settle, followed by disinfection. (As mentioned, some groundwaters do not require the settling and filtration steps.) Some water treatment also involves softening to remove excess mineral content (iron, manganese, hardness, etc.) and/or treatment with activated carbon (to remove natural and man-made organic contaminants). After human use of the water, what becomes of it? If it is collected into a sewer system for discharge into surface water (or even if it is to be injected into the ground in many cases) treatment to remove contaminants caused by use is necessary. In irrigation, any water not absorbed into the plants (a very small amount is actually used by the plants) will seep into the groundwater or evaporate into the air. Insutrial water is either dumped into the sewer system or treated and disposed of like domestic wastewater (although some industrial wastewater is injected into the ground using seep wells). What, then, is water conservation? It can be using less water (e.g., not watering crops or irrigating crops, by engaging in these practices in ways that uses less water, or by limiting or banning certain uses, like car washing). It can be in re-using water in ways that will not cause human disease or environmental damage (e.g., using bath and laundry water for watering lawns or irrigation, or recycling water through an industrial process or into another process). It can also mean separating the flow of wastewater from some sources, in order to limit addition