A dam is a structure made by pouring water from a higher elevation onto lands that are lower in elevation. The dam can be constructed to control flooding, or to supply hydropower for the towns above it. dams have many uses, but primarily as power generation facilities. In most cases, a dam will be built on a large mountain, or other high place, and will act as a storage reservoir for rainfall. In periods of heavy rainfall, the water that would normally come down to the lowest level in a stream or river, will go into the dam, and the dam will hold the water, which will in turn flood the land downstream of the dam.
A dam is often built in an area where the land is not suitable for other types of water infrastructure, such as in a desert. For this reason, many dams are strategically placed to catch more than one seasonal flooding. In order to provide the public with hydroelectric power, there are dams that damming rivers and release power as they flow through it. This power can then be used to power various businesses, farms, and homes. Dams also help to regulate the runoff from rivers and streams, which reduce the amount of sediment and harmful chemicals that enter into waterways.
A dam can either be constructed above the ground, or at least partially above the ground. In many cases, when the dam is partially constructed, it acts as a generator to power the electricity needed by the surrounding community. In other cases, the dam will be constructed inside of a reservoir, and once constructed, it will be surrounded by a fence that seals off the rest of the property. A dam can be constructed anywhere along a river or stream, so it can be used for hydroelectric power generation, or to regulate the movement of water within a body of water. Damming a river or stream is considered to be illegal, as it damages the natural environment, but sometimes it is necessary to construct dams in order to control flooding.