Dams :: essays research papers

Many people havealready dammed a sensitive stream using sticks andmud by the time they become adults. Humanshave used dams since early civilization, becausefour-thousand years ago they became aware thatfloods and droughts affected their well-being andso they began to signifier dams to protect themselvesfrom these effects.1 The basic principles of damsstill apply today as they did before a dam mustprevent water from being passed. Since then,people have been continuing to build and perfectthese structures, not knowing the full intensity oftheir side effects. The hindering effects of dams onhumans and their environment heavily outweigh thebeneficial ones. The paragraphs beneath will provethat the construction and presence of dams alwayshas and will continue to leave devastating effectson the environment around them. Firstly, tounderstand the dissertation people must know whatdams are. A dam is a barrier built across a watercourse to hold back or control water come down. Damsare cl assified as either storage, diversion ordetention. As you could probably notice from itsname, storage dams are created to collect or holdwater for periods of time when there is a surplussupply. The water is then used when there is alack of supply. For example many small damsimpound water in the spring, for use in the summerdry months. Storage dams also supply a watersupply, or an improved home ground for fish and wildlifethey may store water for hydroelectricity as well.2A diversion dam is a generation of a commonlyconstructed dam which is built to pass on sufficientwater pressure for pushing water into ditches,canals or other systems. These dams, which arenormally shorter than storage dams are used forirrigation developments and for diversion the ofwater from a stream to a reservoir. Diversiondams are mainly built to lessen the effects of floodsand to trap sediment.3 Overflow dams aredesigned to carry water which flow over thiercrests, because of this they must be made ofmaterial s which do not erode. Non- overflowdams are built not to be overtopped, and they mayinclude earth or rock in their body. Often, twotypes of these dams are combined to form acomposite structure consisting of for example anoverflow concrete gravity dam, the water thatoverflows into dikes of earthfill construction.4 Adams primary function is to trap water forirrigation. Dams help to decrease the severity ofdroughts, increase inelegant production, andcreate new lands for agricultural use. Farmland,however, has its price river bottomlands flooded,defacing the fertility of the soil. This agriculturalland may also result in a loss of natural artifacts.Recently in Tasmania where has been pressure