Flood Risk and Vulnerability Analysis Report

In 2010, the Government of Newfoundland and Labrador contracted AMEC Environment & Infrastructure (now Wood Environment & Infrastructure Solutions) to conduct a Flood Risk Analysis Project to identify communities at risk to flooding and the potential impacts of the changing climate. In 2009, the Government initiated new studies focused on both the development of flood plain mapping for communities which had not previously had such mapping. However, with over 500 communities across the Province and limited budgets to complete such studies, a framework was required to assist the Provincial Government in choosing communities which would most benefit from assistance with flood risk mitigation and adaptation, resulting in the Flood Risk and Vulnerability Analysis Project. A series of tasks were done as part of the study to assist future planning and adaptive capacity and resiliency building efforts. AMEC updated the Province’s flood events inventory; assessed existing flood risk maps; assessed need for new/updated flood risk mapping; assessed need for flood forecasting/flood warning system; and identified flood vulnerability mitigation and adaptation strategies.

Understanding and Assessing Impacts

To assist future planning and adaptive capacity and resiliency building efforts, a series of task were undertaken as part of the study, including: an update to the Province’s flood events inventory for the period of 1950 to 2011; remote sensing and land cover classification; climate change impacts assessment; assessment of need for new/updated flood risk mapping; assessment for the need for flood forecasting. For the climate change impact assessment, flooding risk was considered for 2020, 2050 and 2080. A range of approaches were used from modelling to qualitative research. For example, Numerical Weather Prediction (NWP) model data was obtained through the Canadian Climate Change Scenarios Network site16 (CCCSN) to project temperature and precipitation changes. Other studies included literature reviews and publications by the Government of Canada on changes to temperature and precipitation over the province. The contractor, AMEC, also produced updated Intensity Duration Frequency (IDF) Curves for some sites. The updated IDF values for Gander and Goose Bay, showed that more intense precipitation events were already beginning to register in recent years. Finally, they considered other events that could lead to flooding such as storm surge, ice jams, spring snow melt and even the saturation of the soil.

Identifying Actions

A list of recommendations was developed based on the determined prioritization for updates to the communities existing flood plain maps. In total, there are 529 communities identified in Newfoundland and Labrador. In addition to flood plain mapping updates, AMEC (now Wood Environment & Infrastructure Solutions) recommended a suite of flood mitigation measures that Provincial government officials and the decision makers should consider for adoption to most effectively serve and protect population, property, and infrastructure. It is recommended that every community across the Province, including those not designated as a high priority for map updates, implement an active process, at a level appropriate to their issues and needs, to develop, renew and update local flood mitigation mechanisms, as a result of land use, watershed conditions, and climate change effects. AMEC recommended that communities each have a Flood Mitigation & Adaptation Program that is applicable to the size of their community, their flood vulnerabilities, and the potential for loss of both life and property. Specific recommendations for each region and sub-region in the province were also provided.

Outcomes and Monitoring Progress

The analysis produces a series of recommendations to assist the Government of Newfoundland and Labrador in its future planning and adaptive capacity and resiliency building efforts. Recommendations are provided in a series of categories, including: Update of the Flood Events Inventory, Remote Sensing and Land Cover Classification, Assessment of Climate Change Impacts, Assess Need for New / Updated Flood Risk Mapping, and Assess Need for Flood Forecasting / Flood Warning Systems.

Resources

Link to Full Case Study