Hay River adopts ice jam flood maps in zoning bylaw

Hay River’s town council has passed a new zoning bylaw influenced by updated flood mapping, though one councillor says more information is needed on the latest flood standards.

The updated Zoning and Development Bylaw now relies on 200-year ice-jam flood mapping completed in 2025 to determine the elevations at which buildings should be constructed, instead of previous 100-year flood maps from the 1980s that didn’t consider ice jams – one of the leading causes of flooding in the NWT.

Councillor Tom Lakusta, who was the only vote against adopting the amendments to the zoning bylaw, said he hoped council would delay second and third readings. Doing so would allow more information to be made available on the science behind the mapping of flood elevation levels and their economic impact on private lots, he said.

“Our information is not complete,” said Lakusta.

The zoning bylaw passed at an August 25 council meeting with the majority of councillors voting in favour.

During the council meeting, Lakusta questioned differences between information in 2023 territorial guidelines and how flood mapping was being adopted now, particularly around the inclusion of freeboard – the minimum construction height in flood hazard zones.

Glenn Smith, Hay River’s senior administrative officer, said the incorporation of flood mapping in the zoning bylaw (and the town’s community plan, which passed its second reading and now must be approved by the GNWT) is informed by the latest information provided by the territorial government, including a 2026 guidance document.

Smith said the updated flood elevation levels – how high water could rise during a flood, which is used to calculate freeboard height – were calculated by GNWT scientists who compared old and new flood mapping data in 10 Hay River locations.

Most of the locations analyzed were on Vale Island, an area historically affected by flooding, where flood elevation levels increased by 19 to 85 cm depending on the location. Results for Paradise Valley showed even greater variation, with flood elevations increasing by as much as 380 centimetres, Smith said. One location on Eagle Crescent saw a decrease of 15 cm, while another in the downtown showed an increase of about 28 centimetres.

While council considered increasing freeboard to 50 cm above the flood elevation level, they ultimately decided to keep it at 30 cm, the minimum height recommended in the GNWT’s 2026 document.

Lakusta said 2023 guidelines for ice jam flood mapping advise against using “a freeboard approach as a type of assessment.”

Similar questions about the flood maps were raised at an August 17 public hearing on amendments to the community plan and zoning bylaws.

In the August 25 council package, town staff said they are creating “supplementary mapping tools to assist property owners and approving authorities in understanding anticipated flood levels and flood construction elevations on individual properties.”

Lakusta told council they should be more informed on what the bylaws require people to do, and why, before they are passed.

“We need to show some certainty to people that wish to develop in these areas,” said Lakusta.

Hay River says it is already designing or upgrading municipal infrastructure – like its lift station, Airport Road, the western channel berm system and storm system backflow protection – with flood mitigation in mind. The town is also working on a community climate adaptation plan.

“Together, these initiatives represent a coordinated approach to protecting residents, businesses, municipal infrastructure, and future development from flood risks,” the town said in a Facebook post about its flood mitigation strategy.