Im Harz gibt es zahlreiche Talsperren, welche meist zum Zweck der Wasserstandsregulierung, der Trinkwassergewinnung und der Erzeugung von Elektroenergie erbaut wurden. .....Die meisten der künstlich geschaffenen Seen befinden sich im westlichen und zentralen Teil des Harzes. Sie sind heute außerdem beliebte Orte der Erholung. An vielen der Stauseen ist auch eine aktive Freizeitgestaltung möglich (z.B. Wassersport, Angeln).
Types of Reservoirs
The term “reservoir” can refer to a man-made or natural lake, as well as cisterns and subterranean reservoirs. In this section we focus only on man-made reservoirs.
Man-made reservoirs are made when dams are constructed across rivers, or by enclosing an area that is filled with water. There are two main types of man-made reservoirs: impoundment and off-stream (also called off-river).
Reservoirs can vary in size and be as small as a pond and as big as a large lake 
. There is so much variability when it comes to reservoirs – they can differ in size, shape and location. For this reason, it can be misleading to make blanket statements about reservoirs without “significant qualification as to their type” 
Depending on the purpose of a reservoir, operators will fill a completed reservoir with water, let water flow on through the dam and downstream, or leave the reservoir site empty until it is needed (e.g. a dry dam site for flood mitigation).
Reservoirs are human-made lakes created by the damming of rivers to serve one or more purposes, such as hydropower production, water supply for drinking, irrigation and flood protection.