According to data collected by scientists with the territory’s Environment and Climate Change Department, the spring break-up of ice on the Hay River continues with water levels remaining “well below average.” As of 2 p.m. today, the data collected also showed that break-up risk has passed for the community of Fort Liard.
While levels measured at the town of Hay River and at the AB/NT border are continuing to rise, scientists said that snowmelt is “near complete” in the Hay River basin.
“There are sections of intact ice and open water between the AB/NT border and the town of Hay River,” said the report’s authors.
They said that forecasted above average temperatures this week will likely bring continued ice degradation and break-up.
Researchers advised to head to the town of Hay River’s website for the most up-to-date information.
Scientists reported that the break-up risk for Fort Liard has passed with nearly all of the river ice no longer visible.
The researchers added that small areas of rubble ice could still be present upstream of Fort Liard.
They also pointed out that above average temperatures forecasted for this week will likely result in continued snowmelt coming from higher altitude areas within the basin.
Data also showed that break-up is progressing along the Mackenzie River between Fort Providence and Fort Simpson.
On Tuesday a large large section of rubble ice moved downstream past Fort Simpson and this made for an open water section near the community.
A minor ice jam was reported near Fort Simpson.
“According to satellite imagery from May 5, a small ice jam (~20 km in length) is sitting approximately 10 km downstream of Fort Simpson,” said the report’s authors.
They added that river ice remains largely intact between Fort Providence and Martin Island. which is an island located about 5 km upstream of Fort Simpson.
One gauge on the river near Fort Simpson gauge is not able to show measures because it was impacted by ice, but the gauge near the village of Fort Simpson is still working, reported scientists.
The measures indicate that the river is rising.
“The water level rose to approximately 11 m as of 10:30 on May 5 and was 7.2 m as of 09:00 this morning (May 6),” noted scientists.
According to previous records, the peak water level at that gauge during the Fort Simpson flood of 2021 was 15.99 m (on May 14, 2021).
Scientists said that near Jean Marie River the water level is slowly rising below ice that remained intact as of 2 p.m. on Wednesday.
The report’s authors said that the average temperatures forecasted for this week along with a “significant” precipitation event could have an impact on levels.
About 10 to 20 mm of precipitation is forecasted to arrive in the area by this evening and scientists predict it will result in more ice movement and ice degradation along the Mackenzie River.
Scientists noted that the potential and severity of flooding will depend largely on weather over the next weeks and its influence on existing ice conditions, water levels and snowpack amounts.
They said the primary factors influencing water levels in the spring include ice jams, which can cause “out-of-bank” water flows (even amid below normal flows) and rate of melt of ice and snow.
The rate of melt can be gradual or quick. The rate of melt is influenced by weather conditions from temperature to rain on snow or ice events. Rain can cause a more rapid melt.
Additional factors that can come into play include current water levels, the wetness of the ground during autumn and snowpack.
More details of the findings for the Liard River, Hay River and Mackenzie River along with weather data including forecasts are outlined in the report.
On Monday, a message from the territorial government advised those living in the N.W.T. to make an emergency plan, build an emergency kit and follow local government notifications.
