Floodplains are low lying areas near a watercourse that are subjected to flooding and unstable slopes due to erosion. In eastern Ontario, the 1:100-year floodplain is the regulatory standard used to identify lands that are vulnerable to flooding. Conservation Authorities in Ontario, including MVCA, are responsible for floodplain management, achieved primarily through the requisition of accurately engineered floodplain mapping data and documentation.
The Carp River is a major watershed within the Mississippi Valley Conservation Authority’s jurisdiction and has been identified as one of MVCA’s highest flood risk areas in the recently completed Flood Risk Assessment Study (2022). Considerable flooding has occurred along the Carp River in 1998, 1999, 2005, 2008, 2009, 2014, 2017, and 2019. Due to significant land use changes and developments, particularly in the upper watershed in Kanata, the current floodplain maps, developed in 1983, require updating.
MVCA is currently developing regulatory floodplain mapping update for the Carp River that will help us and our municipal partners understand flood hazards and implement effective mitigation strategies to reduce the impacts of flooding in the Carp River watershed. The mapping will also inform MVCA’s flood forecasting and warning and emergency management programs.
Floodplain mapping involves many components, including data collection, hydrological and hydraulic analyses, public consultations, and floodplain and regulatory limit mapping. As of May 2023, the hydrological analysis and bathymetric and hydraulic structure survey components of the project have been completed, while the hydraulic analysis is underway. Technical review of the project will be conducted by a third-party engineering firm in summer 2023.
A Public Open House is planned for autumn 2023 when the public will be able to review the draft regulatory floodplain maps. All community members and stakeholders are encouraged to attend – details will be posted on MVCA’s website, social media sites, and local news outlets. The project is being carried out with support from our partners at the City of Ottawa. It has an anticipated completion date of December 2023.