Standard reservoir

a) retention time c) released e) treatment g) hold

b) water level d) live f) well

A raw water reservoir doesn't simply 1) _______ water until it is needed. It is the first part of the 2) _______ process. The time the water is held for before it is released is known as the 3) _______ _____, and is a design feature that allows larger particles and silts to settle out as 4) _______ as time for the biological treatment of algae and bacteria by plankton-like creatures that naturally 5) _______ within the water.

Water is then 6) _______ from the reservoir, generally by gravity, to be cleaned (for drinking water). In the event that major rain occurs, water can be released, decreasing the reservoir's 7) _______ _______.

Hydroelectric reservoir

a) electricity c) built e) released

b) reservoir d) rely f) drinking

A hydroelectric power station consists of large turbines that 1) _______ on a gravity flow of water through pipes from the dam to turn a turbine to generate 2) _______. The water can then be either 3) _______ to the surrounding water course or pumped back into the 4) _______ and reused. Generally, hydroelectric dams are 5) _______ specifically for electricity generation and are not used for 6) _______ or irrigation water.

Irrigation reservoir

a) drinking water b) water c) full d) canals

1) _______ in an irrigation reservoir is released into networks of 2) _______ mainly for use in farmlands or secondary water systems. Water in an irrigation reservoir is generally not used for 3) _______, but in some cases is. As with all reservoirs, water can be released if the reservoir is too 4) _______.

Flood control reservoir

a) flooding b) rainfall c) collect d) "Attenuation"

Commonly known as an 1) _______ reservoir, these are used to prevent 2) _______ to lower lying lands. Flood control reservoirs 3) _______ water at times of unseasonally high 4) _______, then release it slowly over the course of the following weeks or months.

Recreational reservoir

a) safety b) purpose c) are built d) fishing

Very rarely is a reservoir built solely for a recreational 1) _______. Most reservoirs 2) _______ to a civic purpose, but still allow 3) _______, boating, and other activities. At most reservoirs, special rules apply for the 4) _______ of the public.