N.W.T. residents should prepare for 'near-certain' flooding

Northwest Territories residents are urged to prepare their homes, cabins and properties due to flood risk.

That includes "near-certain" flooding on the Tazin and Taltson rivers.

There's an elevated risk of flooding, based on the latest data, in areas which include:

• Hay River (Great Slave Lake)
• Nahanni Butte (South Nahanni River, Liard River)
• Fort Liard (Liard River)
• Fort Simpson (Liard River, Mackenzie River)
• Aklavik (Mackenzie River
• Yellowknife, Old Town area (Great Slave Lake)

The warning comes as the latest snow surveys on water level and flow rate show "above average snow pack levels" in many regions, according to a news release Friday. The survey also confirms higher than normal water levels and flow in nearly every region.

The territory says its hydrologists caution of much higher snow melt peak than usual, "with a high likelihood of nearing or exceeding historic spring water levels."

"This may have consequences for home, cabin and property owners in the N.W.T."

Water levels in both Tazin and Taltson river basins continue to be the highest on record for this time of year, the territory warns, and they will be further affected by high snow pack.

There is a high likelihood of exceeding the record-high water levels experienced last fall, the territory says.

At the mouth of the Tazin river there is usually an average flow of 25 cubic metres per second. Right now, the flow is more than double — 58 cubic metres per second.

Meanwhile the Taltson River, below the hydro dam currently has an average flow of 234 cubic metres per second, double its average flow of 115 cubic metres per second.

Many other water bodies, which experienced record high water levels during the summer and fall of 2020 due to significant rain, continued to see high water levels through the winter and into spring.

The Dehcho (Mackenzie River) at Fort Simpson, for example, which usually has a flow of 2,840 cubic metres per second now has a flow of 4,790 cubic metres per second as of April 12. 

"Higher snow levels in many areas are also expected to result in higher water during spring melt," the release states.

The conditions of melt are unpredictable and may depend on timing, intensity, existing soil and basin conditions, current water levels, snow pack, ice jams, break up conditions and rate of melt and rain events, the territory says.

It suggests people get prepared and to do it as early as possible.

That includes moving valuables and equipment to a safe place, removing or elevating electrical components, removing or elevating carpets, furniture and mattresses and getting familiar with your community's emergency plan.

Evacuation warning for Hay River

Hay River's director of protective services said residents should begin preparations for a one-week potential evacuation sometime between the end of April and early May. 

This includes:

• Moving equipment, vehicles and belongings stored outside to locations that are safe from flooding.
• Pump out your sewer tanks as the flood risk increases.
• Landscape a downward slope away from your house in all directions.
• Install barriers for low-lying assets that can't be relocated.
• Elevate supplies stored in garages and sheds.
• Prepare and check sump or other pumps that may be used on the property.  
• Install weather protection sealant around the base of any low-level doors.  
• Turn off furnaces if not needed.
• Take special precautions to safeguard electrical or propane heating.

For people who do not have COVID-19 and are not required to isolate, the following temporary accommodations are recommended: 

• Stay with friends or family for a maximum of five additional persons for a maximum of 10 people in each house.
• Stay at the RV Park (Hay River Community Centre) for those who have RVs or Campers. Power is provided and there is no cost to the evacuee.
• Stay at the Hay River Community Centre, where a cot and blanket will be provided, and basic food service offered at no cost. 
• Take up commercial accommodations such as hotels or apartments at your own cost.