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Category Archives: Types

Dam Types


True Run-of-River

Waterpower Structures – Definitions

A major challenge is that many of the new proposed dams in Ontario are being sold to the public as Run-of-River, when in fact they are “modified run-of-river”, or using a “cycling” strategy where head ponds are necessary.  Definitions and terminology continue to evolve and change as negative impacts are attached to them, and this has become a real problem.  This government has not created a standard of reference, so in our search to find an authoritative definition for run-of-river, we have settled on a national standard.


Most people when they hear the term “run-of-river”  for hydroelectric generation, have a picture in their mind of a hydro plant that uses only the water that is available in the natural flow of the river, with no water storage, or manipulation of flow, so that power generation fluctuates with the stream flow.   This is in fact how Natural Resources Canada defines run-of-river in their textbook, CLEAN ENERGY PROJECT ANALYSIS: RETSCREEN® ENGINEERING & CASES TEXTBOOK, SMALL HYDRO PROJECT ANALYSIS CHAPTER:

“Run-of-river developments:  “Run-of-river” refers to a mode of operation in which the hydro plant uses only the water that is available in the natural flow of the river, as depicted in Figure 6. “Run-of-river” implies that there is no water storage and that power fluctuates with the stream flow.” Continue reading