Glossary

Reservoir

An area upstream of a dam where water is or can be stored for a long period of time (several weeks and sometimes months). A large reservoir can regulate (or alter) the flows in the downstream river section.

Run-of-river Dam

A type of hydroelectric facility where no or little water is stored. A dam is built to cause water to pond upstream, ensuring the river water is high enough to enter the pipes leading to turbines. A run-of-river facility has little ability to regulate (or alter) the flows in the downstream river section.

Synonym: run-of-river facilities. 

Runoff

The excess water, from rainfall or snow melt, that isn’t retained in the ground and flows into the surrounding streams.