The role of the decision-making process on shoreline armoring: A case study in Quebec, Canada

Abstract

Shoreline armoring has repercussions on coastal processes, including reducing the width and height of sandy beaches, which affect coastal ecosystems and ecosystem services. This project, consisting of two parts, was carried out in the Canadian province of Quebec, on the coasts of the St. Lawrence Estuary and Gulf, which cover the territory of 21 coastal Regional County Municipalities (RCM). The objectives were to characterise shoreline armoring in Eastern Quebec, to determine the role played by coastal managers, coastal citizens, and coastal engineers in the coastal defence decision-making process, and to identify possible actions to be taken by each stakeholder to improve coastal engineering development. First, over 3300 km of shoreline were segmented and characterised, allowing the mapping of what proportion of the shoreline was covered by artificial structures. In 2017, coastal defence measures (CDM) occupied about 10% of the shoreline, and 97.6% of them were reflective rigid structures. The second part of the project involved three different consultations carried out in 2017 and 2018 with 300 coastal managers, 494 coastal residents and 51 professionals from environmental and engineering firms to assess their knowledge of CDM types and functions, and to discuss about the decision process leading to the CDM identification. Results of the consultations show a significant change in the type of desired solutions compared to previous studies where rigid structures were clearly preferred. But despite a greater prioritization of soft techniques by professionals from municipalities, ministries' managers and coastal citizens, the rigid structures continue to be the type of solution mostly implemented along Quebec's coasts. This difference can be explained by a number of factors: a lack of specialized knowledge; a lack of funding; a lack of collaborative process; and regulations that are too restrictive for innovative CDM. In addition to an increase of funding for preventive CDM, for long term CDM monitoring and maintenance, for case studies and pilot projects, the main solutions proposed were interdisciplinary projects based on consultation, adjustment of environmental regulations, and development of a tool that would enable decision-makers to evaluate each option in a particular context, so as to identify the most appropriate solutions and make better decisions for the long term.