Falls Journal
Laurel Beager
Officials involved in Borderland water levels said last Tuesday they see little risk of flooding this spring as recent cold temperatures have helped in reducing the run-off normally expected later.
In addition, a group reviewing rule curves that guide the management of the lake levels are nearing completion of a two-year process that’s expected to result in a recommendation to the International Joint Commission in May.
The final report is expected to be presented to the public in June, followed by public hearings on the recommendation this summer.
The Rainy-Lake of the Woods Watershed Board’s Water Levels Committee reviewed basin conditions and discussed spring water level regulation, said Matt DeWolfe, who advises the committee.
Col. Samuel L. Calkins, U.S. Section co-chair of the water levels committee, gave an update last Tuesday on the winter conditions of the basin and the outlook for spring, noted DeWolfe.
“His take-home message was the committee doesn’t see any particular risk heading into the spring but will keep their eyes open, of course,” he told The Journal last Wednesday.
Nolan Baratono, a member of the water levels committee, noted the water levels committee and study board are very different and intentionally separate to ensure the latter can complete a clean review of the curves.
DeWolfe is a member of the study board, which met earlier in the day with the public advisory group, made up of more than 30 people in the local area spread across the watershed from Rainy River, Ont. to the west to Crane Lake in the east, on both sides of the border.
“We’re very close to the end and trying to zero in on a possible alternative we could recommend to the commission to modify the rule curves set in 2000 if necessary,” DeWolfe said.
The 2000 curves aimed to improve navigation and the ecology on Namakan Lake, and replaced ones set in 1970.
The process to consider future rule curves began with a directive of the IJC when it established the existing curves in 2000, calling for a review in 15 years.
Since then, more than 20 studies by various agencies have been conducted toward gathering information for the process.
The shared vision approach is being used to consider the rule curves.
It has been used successfully in other watersheds the IJC is involved with, noted DeWolfe. Key to the approach is transparent decision-making, allowing for public discussions of different opinions on options.
“It’s not designed to get 100 percent consensus but at least everyone understands, even if they don’t agree with the final decision, how it was made and what information went into it,” he explained.
Maintaining the 2000 rule curves is just one option the board has considered. DeWolfe said the study has considered whether the 2000 curves performed as expected, which the group found they did.
Another aim of the study is to determine whether those curves can be improved.
That process has been assisted by computer models to simulate the effects of alternate curves, and by workshops with the public advisory and resource advisory groups.
Potential improvements include lessening the risk of spring flooding on Rainy Lake and the spread of invasive hybrid cattail, and bettering northern pike spawning habitat, wild rice, muskrat winter survival, as well as accounting for inter-annual variability.
Inter-annual variability does not occur, without extreme conditions, each year because rule curves call for the same levels at the same time every year.
That does not benefit the ecosystem, which needs more variability from one year to the next, DeWolfe said.
A “draft decision workshop” conducted last Tuesday included a review of 10 options, seven of which were rejected immediately “because the trade-offs are too extreme,” DeWolfe noted.
Baratono said the impacts to the Rainy River also are being included in the study of the rule curves for the first time, adding to the complexity of the project.
And both Baratono and DeWolfe discussed the effects of climate change may have on the future rule curves.
On Tuesday, DeWolfe said the board zeroed in on three options: maintaining the 2000 rule curves, a flood reduction curve, and a compromise curve.
The flood reduction curve would rely on a spring flood forecast and in risk years, allow in April more water to pass earlier–delaying the refill of Rainy Lake until the middle of July rather than early June, providing more storage room in the case of floods.
But that curve brings concerns, among others, about spring walleye spawning.
A compromise curve has greater concerns, but the study board agreed it could be reconsidered if it were further refined.
DeWolfe also discussed non-rule curve recommendations that include benefits that can be obtained by adjusting operations while staying within the rule curve, improving communication for flood forecasting, exploring adaptive management, which calls for ongoing studies to ensure the curves in place are doing what they are intended, and allowing for adjustments before a 15-year review.
More information can be found at the study board’s website at http://ijc.org/en_/RNLRCS, where videos about the basin also are located.
They also can be found at vimeo.com/207502512 and vimeo.com/189202465.
