British Columbia Mine Reclamation Symposium

River rehabilitation following a dam breach Bronsro, Allan; Ogilvie, John Franklin; Adams, M.; Nikl, L. H.

Abstract

A failure in the glaciolacustrine unit underlying the Perimeter Embankment of the Mount Polley Mine Tailings Storage Facility resulted in a breach along a section of the embankment on August 4, 2014. Approximately 9 km of Hazeltine Creek was significantly affected by the resulting debris flow. The initial channel stabilization work was completed quickly and cost-effectively over five months using a combination of traditional channel design techniques and innovative implementation methods, in particular a field-engineered and constructed approach. The channel morphology was developed to mimic pre-existing conditions, including a low-flow channel and two levels of floodplains. Habitat features were designed for the needs of rainbow trout in the portions of the creek that they used; and sockeye and coho salmon in the lower reaches. A field-fit approach was used to maximize flexibility and was consistent with the adaptive approach used in the overall environmental response. A series of design ‘templates’ were developed for each of six morphologically distinct creek reaches, and these templates were applied in the field using a team of professional engineers and biologists and experienced machine crews that implemented those field designs, proving to be highly effective based on the intended outcomes and the rapid timelines under which the construction occurred.

Item Citations and Data

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International