A water tank is a container which is used to hold water. Water tanks are used in a wide variety of settings and for an assortment of purposes all over the world. Many home improvement stores sell water tanks, and a tank can also be constructed and installed from raw materials as a custom job for specific applications. Since humans rely heavily on water to survive and perform numerous tasks, it should come as no surprise to learn that people have been devising water tanks and other storage techniques for centuries.
Some tanks are designed as collectors. They may collect rainfall, or serve as a collection point for water pumped up from a well or piped out of a stream, river, or lake. Once collected, the water can be transported in the tank or transferred to another tank for transport. Collection tanks can be made from steel, plastic, and concrete, depending on how they are used, and they may be attached to filtration systems for hygienic reasons.
Other water tanks act as storage, to ensure that water will be readily available when it is needed. Storage tanks are often used in agricultural operations to provide an uninterrupted supply of water, and they may also be utilized as a backup water supply for homes and buildings. In regions where water supplies are irregular, a storage tank can be extremely useful. A water tank for storage is often gravity fed so that no electricity is required to get water into or out of the water tank, ensuring that the water is always accessible.
Storage tanks can be mounted in place as permanent installations, or they may be mobile. Many fire departments have tanker trucks to transport water to fires, for example, and companies which sell water typically use tanker trucks to move their product around. Mobile water tanks are sometimes used to deliver potable water in the developing world, as it may be easier for aid organizations to process water at a central facility and truck it out than it would be to establish multiple water purification plants across a region.
It is important to maintain a water tank properly. The tank can develop a biofilm which contaminates the water with microorganisms, or a leak which causes loss of water over the long term. Most water tanks need to be regularly emptied and scoured so that they stay reasonably clean, and plumbing to and from the water tank must be inspected to confirm that it is in good working order.