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Ryan Johnson, Forum Communications Co., Published September 02 2010

Pomeroy updated on Devils Lake

A “persistent wet cycle” since the mid-1980s has made it hard to predict just how high Devils Lake will rise next year – but it seems likely it could break the record level that was set this summer, National Weather Service officials in Grand Forks said Wednesday.

Rep. Earl Pomeroy, D-N.D., toured the office to get the most recent information on the lake’s outlook, especially what could happen next spring as the winter runoff flows into the basin.

It’s information that Pomeroy will share with a federal interagency task force Friday at a Washington, D.C., meeting with local officials from Devils Lake, Lisbon, Valley City and other basin communities.

The federal group is preparing to release a report next week of possible next steps to address flooding issues.

Devils Lake has risen nearly 30 feet in elevation in the past 17 years, reaching a record 1,452.1 feet this summer before dropping down to about 1451.6 feet by Wednesday.

Mark Ewens, data manager for the Grand Forks office, explained that it’s becoming more difficult to know just how the lake will react because the climate has been unusual for more than a decade. But there’s one thing that is known – the ongoing wet cycle means that it doesn’t take much precipitation to have a big effect on Devils Lake.

“Our sponge is full,” Ewens said.

Projections

It’s estimated that Devils Lake would spill naturally out of connecting Stump Lake if it reached an elevation of 1,458 feet, which could have disastrous effects on downstream communities.

The U.S. Geological Survey recently projected a 50 percent probability of the lake dropping down to about 1,450.7 feet before the freeze-up this winter. The agency projects the lake will rise up to about 1,453 next spring – which would break this summer’s record and bring the elevation to within 5 feet of a natural spillover.

Mike Lukes, hydrologist with the weather service in Grand Forks, used the USGS projections and the average 240,000 acre-feet of spring rise that’s been seen on the lake since 1993 to come up with his own calculations.

Lukes’ “back-of-the-envelope” prediction is for the lake to hit 1,452.1 feet next spring, but he pointed out the figure is “kind of low-balling” what could actually happen next year.

Ewens told Pomeroy that long-term outlooks for the level of Devils Lake are based on 60 years of historical data, which helps the USGS come up with probabilities of what the lake will do by looking at previous effects of storms, spring runoff and other factors.

But the region has been in a wet cycle with an unusual climate since the 1980s, meaning what’s happened to Devils Lake in recent years seemed unlikely on the forecasts released by the USGS.

“We’re in a very unique climate regime versus what the bulk of the history of the lake is like,” Ewens said. “As long as we continue in this wet cycle relative to prior to 1985, the lake will continue to react at those lower probabilities.”

Pomeroy said he’s been hoping the lake’s rapid rise in recent years would turn around, but officials have to prepare for bad outcomes that could happen from a spillover.

“That’s why we’re having the meeting Friday,” he said. “This has gone from, ‘This can’t happen,’ to now it’s within a few feet of an overflow event. We’ve really got to start making a different level of preparation.”

And Pomeroy emphasized that this work will result in an “action plan,” not just “another federal report that sits on a shelf.”

“I want this to literally guide the agencies in a concerted way across jurisdictional boundaries toward dealing with the increasing possibility of lake overflow,” he said. “Let’s call it the playbook to avoid catastrophic flood overflow out of Stump Lake.”


Ryan Johnson is a writer for the Grand Forks Herald