The County of Haliburton believes it will be well prepared the next time a 100-year storm rips through the community.
In September, regional staff partnered with representatives from the Ganaraska Conservation Authority and the Kawartha Lakes Conservation Authority to kick start a new bathymetry surveying project of the Gull and Burnt River watersheds.
The information will be used to improve flood protection practises in the area, said Steve Stone, the County’s director of planning.
The project is being funded by the federal government through its National Disaster Mitigation program, launched in 2015. The initiative is designed to reduce the impacts of natural disasters on Canadians through focused investments on significant recurring flood risks, while also advancing work to facilitate private residential insurance for overland flooding.
Stone said the County plans to use the approximately $175,000 it received from the feds to create new floodplain mapping for the reservoirs, lakes and connecting rivers that experience frequent flooding around the Highlands.
The idea is to avoid the sort of situation seen in 2017, when the Gull River burst its banks, flooding many riverside properties.
“We’re trying to introduce science into why these disasters are happening and, ultimately, come up with a mitigation plan for them,” Stone said
Project to wrap up December 1
There have been several funding intakes since the program was launched six years ago. The County initially applied for, and received funding in 2017. That money was used on LiDAR mapping of the watershed, which involved commissioning airplanes to fly in a straight line over certain areas of the County to form a digital map of the terrain below.
That terrestrial mapping project, as Stone calls it, is still ongoing. While it was expected to wrap up in 2019, the COVID-19 pandemic forced the County to put it on hold. Those involved in the work are only just now getting back to it, Stone said.
The bathymetry project is a second, separate intake that involves the use of SONAR technology to get an accurate read for what different waterbodies look like under the water line.
“We’ve basically broken this down into three phases – we’re going out, surveying in the water, looking at what the terrain looks like in the rivers and lakes in a few key areas. The Gull River is our primary focus right now, because of the flooding that’s happened there in the past,” Stone said. “The net result of all this survey work is that we’ll have data that the conservation authorities can plug into a model. Then, based on what we find in the water, and the features along the different rivers and lakes, they will be able to accurately figure out where the floodplain is, and based on rainfall, snowfall etc. accurately plot where this theoretical floodplain is within all the major rivers that cycle through Haliburton County.”
Stone noted this information will be used to direct public policy and assist in the decision- making process when proposals for new or existing developments along potential floodplains come before council.
While the first phase is focused on populated areas around the Gull River – most notably the village of Minden – the second and third phase will focus on more outlying areas, covering the southern portion of the Gull River watershed. Stone expects all three phases to be wrapped up by Dec. 1.
Public consultation is expected to take place in late 2022 and early 2023, presenting the project’s findings, before being officially presented to County council and the four lower tier municipalities.
“This is the sort of thing that will lead to better mapping and better policies as it relates to development in and around our County’s rivers,” Stone said. “This is the sort of thing that will lead to better response (during extreme storm events). I guess you could say we’ll be more preventative, because we’ll know more and, hopefully, through our preventative measures we’ll end up mitigating some of the potential for severe damages in the future.”
