Nearly five years after the destructive 2017 floods, flood mapping aimed at making B.C.’s Okanagan more resilient is starting to have a tangible impact.
Building on floodplain mapping done by the Okanagan Basin Water Board around Okanagan Lake, the City of Vernon has recently completed its own floodplain maps of local creeks.
The municipality is looking at upgrading infrastructure and changing development rules to minimize loss when waters rise.
“What we found is that the risk of flooding is fairly high but it is increasing over time,” said Anna Warwick Sears, the executive director of the Okanagan Basin Water Board.
“What we looked at was the flood of 2017, which is the biggest flood in living memory. That flood was considered a 1 in 500-year event, but with climate change, it will happen more and more frequently. So we are asking communities to get ready now.”
The City of Vernon is trying to use the floodplain maps to prepare.
“We could see clearly where our culverts and our bridges were causing constriction and increasing the impact of potential for flooding,” said Mayor Victor Cumming.
“Feasibility work has been approved by council…to sort out where we can, with the least cost and the maximum benefit, provide some new infrastructure in those places to prevent them from contributing to flooding when we have high water levels.”
The municipality is also considering regulation of new development in floodplains.
A key part of the new rules would likely be regulation of “flood construction level,” which is how high above sea level new buildings need to be built.
“We are looking at this seriously now because we see the climate is changing. All the modelling shows that we will get more high-water events,” Cumming said.
In a report to council, city staff said, Vernon currently doesn’t have bylaws requiring developments to be above a specified elevation in flood zones.
“Current practice is to recommend that flood risk be considered in any development plans. The proposed new regulations would make this mandatory,” the staff report said.
This week Vernon council deferred discussing the proposed new regulations, asking city staff to seek more information from the province and the Okanagan Basin Water Board on the proposal.
“We want to make sure we get it right and we want to make sure those…design construction levels are absolutely right.”
The water board says Vernon is among the first wave of Okanagan communities to consider this type of regulation and ideally all Okanagan communities will adopt flood development regulation.
“You don’t have to move everything out of the floodplain and, frankly, in most of the communities in the Okanagan you cannot do that. But what we can do is change how we build and let people know what risk they have so they can make decisions for themselves,” said Warwick Sears.
“If we don’t regulate development in terms of flooding we are putting our communities at risk….It is the responsible thing to do to come up with strategies…to increase flood resilience. All the communities need to do this or else they are just putting people in harms way.”
Vernon resident James Dyson said he wasn’t surprised to get a notice recently advising him his property is in a flood prone area.
“I wasn’t happy with it, but I kind of knew it could be like that being so close to the lake,” Dyson said.
Dyson the retiree is wondering how the proposed regulation will impact those already living in flood zones.
“I don’t like it that it might affect the price of my house but I can certainly understand why they would do it,” Dyson said. “If they regulate it and the price of my house goes down I’d like to get some compensation for it.”
Another factor to consider as Vernon looks to prepare for future high water. Vernon’s flood maps are available here.