Lake and Reservoir waters are natural or artificial places where water is collected and stored.
A lake is a body of relatively still fresh water localized in a basin that is surrounded by land. Lakes are inland and not part of the ocean, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams because they are not flowing. However most lakes are fed and drained by rivers and streams.
A reservoir is an artificial lake that is used to store water and produce other amenities. Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such a brickwork or cast concrete.
Lakes, natural or artificial ponds and constructed reservoirs are used for the storage and regulation of water, especially water for supplying a community, irrigating land, furnishing power, etc.
A lake and reservoir water with a surface outlet represents a holding and mixing basin for water from streamflow. The retention time of water in a lake provides a potential opportunity for slow reactions to come closer to completion than they can in the rapidly moving water of a stream. Mixing, however, may not be complete. At any given time, the water in one part of the lake may be greatly different in composition and properties from water in other parts of the lake.
Size and shape aside (Morphometry), the essential distinction between lake and stream habitats is the characteristic of water movement. Continuous and rapid flow is the characteristic of the stream, whereas the lake is a still water habitat. Lake water is essentially a standing, quiescent body, although at times wind action stirs the surface layer and margins into great turbulence.
A natural or artificial pond or lake used for the storage and regulation of water, especially water for supplying a community, irrigating land, furnishing power, etc.