A Case Study of Post-Industrial Shoreline Recovery on Canada's Pacific Coast

Maddox, W.R., 2024. A case study of post-industrial shoreline recovery on Canada's Pacific Coast. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 305-309. Charlotte (North Carolina), ISSN 0749-0208. Intensive industrial activity led to rapid geomorphic change of the shoreline in Royal Roads Bay, on southern Vancouver Island, and the cessation of this activity resulted in reversion of the shore towards its pre-industrialized state. Littoral drift of byproduct from gravel mining and transport produced broad sand beaches along a previously cobbled shoreline, reducing erosion to steep supratidal slopes. Improved industrial practices depleted sediment supply and closure of the mine eventually ceased all anthropogenic input to the shoreline, inducing significant shoreline retreat. Volumetric quantification of seasonal sedimentation patterns was completed through repeat surveys encompassing storm season and periods of relatively low geomorphic change. Qualitative research was conducted to substantiate findings of overall sediment loss on the beach platform through the comparison of aerial photographs, satellite imagery, and in-situ photographs. Historical documents and archaeological evidence were incorporated to determine the pre-industrialized state of the shoreline. Results indicate that the dunes created by industrial byproduct prevented natural erosion of the supratidal cliffs leading to long term stability of the shoreline. In the post-industrial period, cliff toe erosion has become the primary source of mixed-clast sediment deposition. The brief modern period of industrial impact to this site permits a unique comparison between a known pre-industrialized and quantified post-industrialized state of an anthropogenically modified shoreline.