The amount of water that would cover one acre at the depth of one foot (325,900 gallons).

Insect species whose larval and juvenile forms inhabit streams or lakes.

Bottom-dwelling. Aquatic organisms that live on or in the stream bed.

The maximum number of organisms that a particular habitat can support over the long-term. Limited by food, shelter, spawning or nesting area, rearing cover, etc.

The addition of coagulant particles to water to aid in removing suspended particles in the drinking water process. 

Aquatic insect that feeds by gathering detritus, bacteria, etc.

The plants and animals that interact in a habitat. 

Overhanging or instream structures such as tree roots, undercut streambanks, boulders, or gabions that offer protection from predators or shelter from strong currents.

Sometimes refers to the swiftest part of a stream flow; otherwise refers to the velocity of the flow, measured in feet or meters/seconds (ft/s, m/s).

A type of stream organism, such as bacterium or fungus, that processes dead organic matter.