MAY 23, 2019 – Kawartha Conservation’s Board of Directors has endorsed the updated flood plain mapping for the Burnt River. The 18-month project was completed by the conservation authority for the City of Kawartha Lakes.
“Technology has improved dramatically since the flood plain mapping was last completed in 1991,” explained Kawartha Conservation GIS/Mapping Technician Galen Yerex. “The updated flood plain mapping will provide better emergency management and planning information to the City and residents.”
With the dramatic flooding that property owners once again experienced this spring, the updated mapping will enhance the protection of people and property by clearly identifying flood-prone areas.
“This project will serve as an important update to the existing flood plain mapping for the area,” said Kawartha Conservation CAO Mark Majchrowski. “Ultimately with newer technology and processes we will be able to refine the Burnt River flood plain mapping with new detailed topographical information. This updated mapping will help protect people and their investments.”
Staff surveyed high water marks during the Burnt River flood events that occurred in 2013 and 2016. These high water marks were used to help calibrate the updated 2019 Burnt River hydraulic model. The model calibration was completed using a flood frequency analysis and the historic high flows measured by the Burnt River flow gauge station.
The flood frequency outputs/flood elevations for the 25 and 50 year flood events meshed well with the high water mark elevation data collected in 2013 and 2016.
The updated Burnt River flood study used several decades of historic flow gauge data, real flood event high-water marks as well as more accurate data compared to the 1991 Burnt River Flood study.
The resulting updated floodline yielded results that were largely similar to the 1991 Burnt River Flood Plain Mapping study in terms of the extent of the floodplain; however, the updated study references better information and almost 30 years of additional water flows, thereby providing greater reassurance of the quality of the updated floodline. This, in turn, helps instill greater confidence in the flood models and for planning purposes.
“Given the historic flooding issues along the Burnt River watershed, this new detailed flood plain mapping will aid in ensuring safe planning and development work and help provide invaluable information moving forward,” said Chris Marshall, Director of Development Services for the City of Kawartha Lakes.