Author(s): K. A. Mazurek; M. Amos; J. Thomson; Arif Akhtar; A. Hallett
Linked Author(s):
Keywords: Drowning; Low-Head Dams; Weirs; Risk Assessment; Dam Safety; Sea Lamprey Barriers
Abstract: This paper discusses the assessment of the drowning hazard and proposed mitigative measures for the weir used as a sea lamprey barrier on the Salmon River in Ontario, Canada. At a barrier, at least a 300 mm drop must be maintained between the weir crest and the downstream water surface to prevent the migration of lamprey to their spawning habitat upstream. However, the maintenance of such a drop often results in the creation of a hazardous flow regime that has resulted in drownings. Using a scale model of the Salmon River barrier, the risk of having hazardous flow conditions at the site was assessed. Then modifications to the barrier to reduce or eliminate this hazard were tested. It was seen that successful modifications must both redirect the plunging flow over the barrier along the water surface and create a cross-flow to disrupt the formation of any secondary eddies that may entrap a body.
Year: 2011