Flood Risk and Vulnerability Analysis Project - Atlantic Climate ...

4. Task D – Assess Need for New / Updated Flood Risk Mapping
The objective of this project task is the identification of communities vulnerable to flooding that
should be considered for new or updated flood risk mapping studies. This assessment has been
founded on the updated Flood Events Inventory, the re-assessment of Flood Risk Maps, a
detailed review of the technical components comprising the existing flood plain maps and
linkage of a variety of datasets relevant to flood risk assessment.
The definition of communities has been based on the Local Government Profile (LGP) number
dataset (XLS file with no spatial referencing). This unique number is assigned to each
community in Newfoundland and Labrador although a few communities do not have a number.
A second dataset of communities in Newfoundland was obtained from Government of
Newfoundland and Labrador, Department of Municipal Affairs, Municipal Planning and Design
Engineering Division. This dataset was used to establish spatial locations of the communities
but did not include an LGP number. Linkage with the LGP number dataset was completed
through comparison of community name.
Please note for Task D the names used for communities and areas are a combination of those
that were in place when the FRM studies were done in the 1980s and 1990s and those reflected
by the new LGP numbers due to a need to use data from both old FRM studies and the LGP
list.
The assessment of some communities has been limited by lack of data which has also impacted
linkage to other datasets such as census data from Statistics Canada. To ensure that
communities were adequately considered in the overall assessment, the prioritization followed a
multi-tiered approach. Factors included in the assessment are outlined below:
4.1 Prioritization Parameters
4.1.1 Age of flood study
The age of flood plain mapping may be a sufficient trigger to initiate a re-mapping exercise.
Flood plains maps will typically be re-evaluated after about 20 years. However, it is
recommended that flood risk maps be updated whenever IDF relationships are updated. IDF
relationships form the basis for hydrologic modeling which is one of the two fundamental
elements of a flood risk assessment; the other being hydraulic assessment. The Canadian
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