become adults. Humans have used dams since early civilization, because four-thousand years ago they became aware that floods and droughts affected their

well-being and so they began to build dams to protect themselves from these effects.1 The basic principles of dams still apply today as they did before; a dam must

prevent water from being passed. Since then, people have been continuing to build and perfect these structures, not knowing the full intensity of their side effects. The

hindering effects of dams on humans and their environment heavily outweigh the beneficial ones. The paragraphs below will prove that the construction and presence

of dams always has and will continue to leave devastating effects on the environment around them. Firstly, to understand the thesis people must know what dams are.

A dam is a barrier built across a water course to hold back or control water flow. Dams are classified as either storage, diversion or detention. As you could

probably notice from it's name, storage dams are created to collect or hold water for periods of time when there

sediment.3 Overflow dams are designed to carry water which flow over thier crests, because of this they must be made of materials which do not erode. Non-

built to provide sufficient water pressure for pushing water into ditches, canals or other systems. These dams, which are normally shorter than storage dams are used

there was a lack of food. In the lack of sun the waterweeds grew and threaten to create diseases such as malaria, where the whole lake's ecosystem would die out.8

controlled and lesgislated river in the world. People who used to raft there now say it is very insafe because of the fluctuating surges of water meant to accomodate

Many little animals and plants which were never discoved and may have had high economic value were to be lost forever. There remains a problem with reservoirs

Heritage register. In the land losses whole communties must leave everything and start again elsewhere.5 The James's Bay Hydroelectric project, hailed to be one of

Some common words found in the essay are:
Dam Building, Colarado River, Lake Brokopondo, Inuit Lands, North American, River September, Columbia River, Recently Tasmania, World Heritage, Basin Brazil, storage dams, people dams, overflow dams, water flow, dam built, dams built, store water, dams protect, animals plants, supply water,
Approximate Word count = 1186
Approximate Pages = 5 (250 words per page double spaced)