Whereas the Inspector of Dikes is required under the Dike Maintenance Act to provide approval of all works on a designated dike, including the seismic performance of the dike; And whereas the provincial Seismic Design Guidelines for Dikes June 2014 require extensive and expensive geotechnical investigations and ground improvement works; And whereas the cost of geotechnical ground improvements to meet the Seismic Design Guidelines for Dikes is very expensive in areas with river and marine sediments: Therefore be it resolved that the provincial government be requested to revise the Seismic Design Guidelines for Dikes to reflect predicted local ground settlement conditions with the primary goal of community flood protection.
Ministry of Forests, Lands, Natural Resource Operations Rural Development The design guidelines for dikes are applicable to newly constructed or existing dikes with major upgrades, classified as high consequence, in southwest BC and on Vancouver Island. The current guidelines were developed by experts and represent the best technical knowledge on the seismic behaviour of dikes at the time 2014. Government understands that meeting the seismic design guidelines for dikes may be costly. However, applying definitive performance measures to maintain the structural integrity of dikes during seismic events, and provide adequate post-event protection from floods, helps protect public safety. In some cases, after a seismic assessment has been completed, diking authorities andor developers may have to consider alternative measures to arrive at practical and cost-effective remediation. The Province has provided 1.1 million to the Fraser Basin Council for geotechnical investigations around seismic upgradesconstruction to dikes in the Lower Mainland, and to develop a seismic program which will review possible alternatives to meeting the current guidelines. The results will inform recommendations to the guidelines and create professional practice guidelines for professionals undertaking seismic assessments of dikes.