Wednesday, October 1, 2014

Board defends lake levels

FORT FRANCES—The annual joint public meeting on the regulation of Rainy and Namakan lakes was held last night at Rainy River Community College in International Falls—and the International Rainy Lake Board of Control was flooded with questions and comments from the more than 70 people on hand.
Col. Daniel Koprowski, American co-chair of the IRLBC, first gave a 20-minute presentation explaining what caused this year’s flooding and the science behind the board’s decision-making.

Then the floor was opened up to the crowd.
Among the first to take the microphone was an outraged resident who lives along the Littlefork River.
“Since 2000, when this new curve has gone in, almost every year [when] the ice goes out, I sit and watch as the water comes up in my back yard,” he fumed.
“This year, you guys put it in my house nine inches.
“Well, let me tell you, thank you—because now I have to move and my life is ruined.
“I hope you guys are all happy,” he added before storming out of the room.
The next person to ask a question asserted that communication between the board and citizens during the crisis was sparse, noting many weren’t prepared for the flooding.
“Maybe in town there was a lot of communication,” the man remarked.
“But for those of us who own a home and don’t live here, there was zero.
“The communication thing has to be improved,” he stressed. “Why would I check the Internet if I was unaware of what was going on?
“If we have issues here, you need to alert everyone, including those of us who live on the lake,” he said.
Although Koprowski was patient in directing questions to professionals surrounding the room, he was quick to refer to the presentation he had made earlier on, which explained circumstances and measures taken.
“What we saw this spring and into the summer was a [sequence] of events that led to almost unprecedented levels of high water,” he had noted.
“In March, what we tried to do was produce some room in the system to account for the big snow pack in the late fall to avoid flooding,” Koprowski explained.
He noted the snow pack was in the 95th percentile, with a melt leading to a water level change around the beginning of April.
Koprowski also said the average rainfall in May here typically ranges from two-four inches (50-100 mm).
This year, however, some areas throughout the watershed were getting up to seven inches (175 mm), which “set the stage for what came in June.”
On a day-to-day basis, the two power companies—H20 Power LP in Canada and Boise Inc. on the U.S. side—decide how much water to release through its dams, as long as they keep the levels within the rule curve band set by the International Joint Commission (IJC).
“What we attempt to do is keep the water in the middle of that rule curve,” Koprowski said.
“But there are times when we need to deviate from that,” he noted. “And when there is extremely high water, we generally target the bottom.”
Koprowski said on March 7, the IRLBC directed the companies to target the bottom 25 percent of the rule curve, referring to the 2000 rule curve used to monitor and regulate water levels of Rainy and Namakan lakes.
“Their deadline was set in April and they achieved that,” he noted. “Then the spring came and the snow began to melt.
“Then we were opening gates and achieved pretty much the maximum flow by May 16.
“We reached ‘all gates open’ on June 6.
“The important point about having ‘all gates open’ is that when all of the gates are open, your ability to adjust is gone,” Koprowski stressed.
“We were ‘all gates open’ and the rain was just beginning.”
The increased inflow affecting Rainy Lake, as well as Namakan, the upper lakes, and Lac La Croix, meant additional water having to move downstream from those areas, as well, Koprowski added.
But many at last night’s meeting were quick to cite the effectiveness of rule curves used in the past, particularly the 1970 rule curve, in protecting the area from high water.
Koprowski outlined the miniscule differences between the two curves in this extreme situation.
“In the 14 years that [new] rule curve has been in effect, we have seen seven of the 20 wettest events since we began keeping records,” he noted.
“The 1970 rule curve only coincided with four of those events, which was an unusually dry period.
“If you compare the two, there is not a whole lot of difference.
“When we do compare them, what you end up with is 2/100th of a foot difference between the two rule curves up against this particular event on rainy lake,” Koprowski said.
“That equates to about a quarter-of-an-inch.
“The fact of the matter is that those two rule curves, in this particular event, would have performed just about identically,” he reiterated.
One person asked why the board wasn’t being proactive in releasing water prior to encountering the flood situation.
“You mentioned on your chart that in May you opened Namakan gates all of the way, however, you delayed opening the gates in town until June 6,” the man noted.
“Why weren’t you proactive in opening the all gates?” he wondered. “Why didn’t you immediately open the gates on Rainy?”
Matt DeWolfe, Canadian engineering advisor with the IRLBC, replied that solving high water levels on the lake is not a simple matter of opening up more gates.
“It doesn’t matter what rule curve you are using or if you come down a foot more in the spring,” he explained.
“If you are a foot lower on the lake, it just means there is that much less water that can be pushed out early on.
“You have to build a lake back up to get back to the capacity you would have been at on Day 1.
“If you start the lake much lower, you have to catch up to that flow rate and that can take weeks,” DeWolfe added.
“In the meantime, you are back to where you started to begin with under this sort of extreme event.
“In a wet year, that is not an extreme event, it could make a difference, for sure,” DeWolfe conceded.
“But with this overwhelming amount of water, we cannot contend with that.”
DeWolfe said no amount of hydrological modelling or rain gauges will make up for the fact we cannot predict what the rain will be a week from now—and that is not going to change.
“Mother Nature’s ability to produce water will always overwhelm our ability to regulate it,” echoed Koprowski.
“We have been asked if this will happen again, and unfortunately the answer is probably as long as it keeps raining.
“So be prepared and plan ahead,” he stressed.

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