Kootenay Lake levels explained

With high water around the Kootenay Lake area, FortisBC offers some answers.

Re: Kootenay Lake levels

With the recent rainfall and high snowpack this spring, there has been some concern from local area citizens regarding how Kootenay Lake operates and why the water level is near a 40-year high.

While we understand that the high water level is a concern for flooding, the conditions that we find ourselves in today are as a result of natural conditions.

The snowpack at Redfish Creek in 2012, just north of Nelson was the highest snowpack on record. The amount of precipitation that the region has experienced in June is forecast to be the most precipitation we have ever received in any individual month, including the winter months. These conditions are not isolated to the Kootenay Lake region, as flooding has been a problem all across the province.

As many of your readers know, FortisBC operates four dams on the Kootenay River. FortisBC’s Corra Linn dam is the closest to Kootenay Lake and can operate as the control point for water flows out of Kootenay Lake.

However, just upstream from Corra Linn is Grohman Narrows, which creates a physical restriction of water flowing out of Kootenay Lake. Since mid-March, FortisBC has been operating Corra Linn dam so that the maximum amount of water can flow out of Kootenay Lake, as limited by Grohman Narrows.

There are two dams upstream that also play a role in Kootenay Lake levels — BC Hydro’s Duncan dam and the Libby dam operated by the US Army Corps of Engineers. It’s estimated that without Libby and Duncan dams in place today, that the current lake level would be approximately seven feet higher with the natural inflow conditions we have seen this year.

FortisBC holds the International Joint Commission (IJC) order for Kootenay Lake, which was established in part to ensure that Kootenay Lake peak elevations would be lower than if the dam had not been constructed. Each year, FortisBC presents its annual operation of Kootenay Lake to the IJC Kootenay Lake Board of Control, which is then followed by a public meeting. This year the IJC meeting will be held in Bonners Ferry in early fall and FortisBC welcomes all concerned lake residents to attend.

I’d ask that if your readers want to get up to date information on Kootenay Lake levels, to please visit our website at fortisbc.com or call our contact centre at 1-866-436-7847 and sign up for our Kootenay Lake level email updates. For safety related concerns regarding flooding, please visit the Provincial Emergency Program website, pep.bc.ca, or contact 1-800-663-3456 to report an emergency.

Barry Smithson

FortisBC Director

Network Operations