Author: Violeta Martin, Ph.D., P.Eng.
Conference: Canadian Hydrotechnical Conference 2015
Date: April 29-May 2, 2015
Run-of-river, diversion-type hydroelectric projects on steep mountainous streams create changes in environmental conditions, including modified hydraulic and sediment transport conditions in the headpond upstream of the flow diversion intake and in the diversion section of the stream between the intake and the tailrace. These types of changes can lead to environmental and operational challenges that require careful consideration at the project design stage in order to achieve a successful, sustainable project.
Hydrodynamic modelling including two dimensional and Computational Fluid Dynamics (CFD) modelling were used to investigate the flow and sediment transport patterns through the headponds and intake structures of one existing and two proposed run-of-river hydroelectric projects located in coastal British Columbia. The intake structures consist of a concrete weir, a Coanda screen or an inflatable rubber weir, an intake facility with conveyance to the penstock entrance, and sluicing facilities for flushing sediment from the headpond. This paper reviews the relevant environmental, engineering and modelling issues for each project and discusses how results from these numerical modelling tools were used in fine-tuning the intake designs.