Big slabs of ice seen over the Nechako. (Aman Parhar/Omineca Express)

Mayor concerned about ice jams in the Nechako river

"We have never lived with a frozen river at this magnitude during our time in council," mayor said.

  • Jan. 12, 2021 12:00 a.m.

The Nechako River currently has ice built up in ways that many have never seen before. District officials are concerned about ice jams, but also about the risk of flooding after spring thaw. However, Rio Tinto said according to their forecasts, the risk of flooding is low.

Vanderhoof Mayor Gerry Thiessen went on an aerial tour of the Nechako in the last week of December. He said council was worried as the water level went up by 5 ft in approximately two days. “That was significant, so we knew the river had to be plugged somewhere. So we flew up to about where Cluculz Creek is, and we saw about 6 to 9 ice jams which were pretty significant.”

“Some were longer than a mile, as per my understanding,” Thiessen said.

But then warmer weather came, and the levels went down, but the river is over a metre higher than what it is typically during this time, the mayor said.

In a response to Express questions, Kevin Dobbin, manager, communication and communities for Rio Tinto BC Works said, “Most parts of the Nechako River freeze through the winter, and ice jams sometimes form as well. If Rio Tinto needs to increase or decrease spillway discharge through the winter, an ice stability survey will first be conducted to determine if it is safe to discharge and we will inform the community.”

Dobbins said the Nechako Reservoir is currently 84 percent full, and the probability of flooding in spring is very low.

“Rio Tinto understands the distress the flooding is causing and has reached out to the BC River Forecast Centre to offer our assistance in any way we can, including sharing river data and forecasting,” he added.

READ MORE: Vanderhoof conservationist questioning the nature of Rio Tinto’s temperature management program

Meanwhile, Thiessen and council has other concerns in the management of the Nechako reservoir.

“Our hope was that when we agreed to get involved in the Water Engagement Initiative process it would give us a chance to communicate our concerns. We know that the smelter in Kitimat requires a certain amount of volume to keep the smelter going. But in our mindset, that is what the reservoir is for – to operate the smelter; not for the sale of hydro to BC Hydro.”

The mayor said council understands there needs to be enough hydro to operate the smelter, but the rest of the water should simulate a natural flow.

“In the spring you would have naturally heavy run-off flow, and then it would slowly come down and go into the Fall, and will be the only run-off you get naturally coming from the water systems that are in the water shed,” he said.

“But instead, right now, we saw this past year a significant flow in the Spring, then we saw another significant flow in August, and now we have seen another significant flow come October, November. So right now the flow is at 84 cubic metres per second, and last year we were at 31 to 32 cubic metres per second. So our understanding, which we don’t have a reason to not agree with, is that it will stay consistent with this until the ice comes off the river,” Thiessen said.

He said even though Rio Tinto nor the Province have expressed concern over the risk of flooding in Spring, council is concerned about the ice jams on the river.

“We understand the snow pack is over a 100 percent in the watershed, and we have had a lot of moisture this past year. Even the Nautley River is putting out more water than it usually does. I think we do have a concern. We have gone back in history to see if the reservoir is so full, what will happen when thaw will come in Spring. So we will work very closely and will be asking Rio Tinto for monthly updates as we want to make sure we don’t flood this year.”

The District does not have an independent hydrologist working for them, as they have been lobbying the province and Rio Tinto to sponsor one for the community.

As the Nechako is a controlled river, and both Rio Tinto and the province make revenue on it, Thiessen believes it is their mandate to fund a hydrologist who could independently guide council.

Currently, council works with the data they get from the River Forecast Centre and from Rio Tinto. They take the data and work with Emergency Management BC.

“The problem is that we have asked for a significant amount of time to the province and to Rio Tinto, and said look you need to sponsor a hydrologist. So we would understand what is the exact concern we should be having right now. For instance, we have never lived with a frozen river, like this magnitude, during our time in council. So to us, if we can understand what we can be advocating for, or what we shouldn’t. We sense in our heart, that a consistent water flow at this time of the year is the right thing to have, so that will keep the water flowing. But we have to say we are not sure, as we don’t have a hydrologist on staff.”

READ MORE: Q & A with Rio Tinto Operations Director

On the question of funding a hydrologist, Dobbin said, Rio Tinto has funded the Technical Group of the Water Engagement Initiative to bring experts such as hydrologists to the WEI, to be available to all participants.

“Rio Tinto has offered to support the District of Vanderhoof by hiring a hydraulic consultant with expertise in ice jams. We have been in contact, and will stay in close contact, with the BC Government and the District of Vanderhoof,” Dobbin said.

Meanwhile, the mayor also said residents need to be careful walking on the trails next to the river, as some are flooded at this time. He also reminded residents about being careful on the river and said it is not safe to be walking on the Nechako when its frozen.


Aman Parhar
Editor, Vanderhoof Omineca Express
aman.parhar@ominecaexpress.comLike us on Facebook and follow us on Twitter

Vanderhoof Omineca Express

 

The river coming over the shore at Vanderhoof’s boat launch area. (Aman Parhar/Omineca Express)

Flooding in parts of Vanderhoof from the Nechako. (Photo courtesy - Mayor Gerry Thiessen)

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