After noticeable highs and lows each year since 2001, water levels on Rainy and Namakan lakes are right where they should be this summer, the International Rainy Lake Board of Control reported at its annual public meeting here Tuesday night.
“The main message we want to get across is how variable things have been the past few years,” said Rick Walden, Canadian engineering advisor for the IRLBC before a room of about 40 people at La Place Rendez-Vous.
In 2001 and 2002, Rainy and Namakan lakes were at the highest they’d been in years due to heavy rains. For instance, in June, 2002, the water level on Rainy Lake spiked above the upper limit of the rule curve (337.8 metres) to peak at 338.6 m.
On Namakan, it reached 341.2 m.
“We had the contrast to that in 2003,” noted Walden, referring to the low levels seen that year.
In June, 2003, for instance, the level on Rainy Lake dipped below the lower limit of the rule curve (337.5 m) to 336.6 m. On Namakan at that time last year, the level followed the lower level of the rule curve at 340.7 m.
“In contrast, 2004, in terms of lake levels, has been a very good year,” said Walden.
The lake levels on Rainy and Namakan made a sharp rise in early April due to an “early snowmelt run-off,” at which time Boise Cascade and Abitibi-Consolidated increased their outflows to maintain lake levels within their bands.
Although inflows to Rainy Lake then declined in the latter half of April, a major storm May 11-12 again increased inflows to Rainy and sustained Namakan inflows.
Rain later that month led to a total rainfall for May of 125 mm (4.89 inches) for the Rainy-Namakan basin—the fourth-highest for the month of May here since 1900.
Currently, both lakes are in the middle of their respective rule curves (337.6 m for Rainy and 340.6 m for Namakan).
Walden noted the highs and low of past few years, while extreme, weren’t record-setting, and will happen again sometime in the future—and the IJC, the companies controlling the dams, residents, and municipalities always must keep that in mind.
“The public needs to understand that shoreland will be flooded periodically,” said Walden, adding property owners need to be aware of level ranges and limit incursion onto “hazard lands.”
And if people must build in “hazard lands,” they should design and construct buildings and structures to minimize inconvenience and damage from high water levels.
Walden also said local governments need to adequately define hazard lands when doing municipal planning—and enforce development standards.
Following the brief presentation, there was a question-and-answer period, but few questions.
Referring to the high water levels in 2002, International Falls area resident Thatcher Peterson asked how quickly Boise and Abitibi are able to respond and open the dams if the lake levels quickly rise, and are they any quicker now after the experience in 2002?
While Walden said both companies are “very responsive” to changes in the lake levels, “the big problem is that we are dealing with a very large basin and the ability to forecast [weather] is pretty limited.”
He noted that in 2001, high water levels resulted from a series of heavy rainfalls, while in 2002, there was a single, major torrential downpour. “The forecasts in both cases was for showers,” he remarked.
“The inflow coming into the lakes was two-four times the outlet capacity of the dams,” he added, noting that at that outflow rate, the lake levels would go up and stay that way for some time even if the dams were open.
Walden said the rule curve changes with the seasons, and is meant to minimize risk of flooding by creating a “hole” in each lake to absorb rainfall (i.e., keeping lakes at a level within the rule curve that at the same time allows for seasonal precipitation).
This amount is based on data from previous years.
He stressed when the various factors are added up, its clear there’s a limit to how much—and how quickly—the outflow of a lake can be controlled.
“You can’t forecast into the future and know what’s coming. You can only try to minimize the risk,” said Walden.
Other business
Several other matters were discussed briefly at yesterday evening’s meeting here. IRLBC member Lee Grim of International Falls noted the IJC, as well as the two companies responsible for the local dams, have been making efforts to make lake levels information more easily accessible to the public.
For instance, the IJC has a new website—www.ijc.org—where regular reports can be found while Abitibi-Consolidated here has a toll-free line (1-800-274-LAKE) which people can call to find out flow rates, whether dam gates are open, and more.
As well, IJC commissioner Allen Olson welcomed Col. Michael Pfenning of the U.S. Corps of Engineers as new co-chairman of the IRLBC.
Col. Pfenning replaces Col. Robert Ball, who resigned to be deputy commander of a U.S. Army base in Fort Wainwright, Alaska.
A similar meeting was planned in Baudette at 10 a.m. on Wednesday.
Fort Frances Times
Local News from Across the Rainy River District
