Snowpocalypse to Floodpocalypse

"People need to realize this is about much more than not being able to walk on the Greenbelt, or not being able to float the river."


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During winter 2016-2017, snow accumulated at double the normal rate. In March alone, precipitation was 325 percent of normal, and the flooding that followed left 35 of the 44 Idaho counties under state or local disaster declarations.

Although an alphabet soup of agencies collaborated to manage the excess runoff, complete control proved impossible. Looking back, officials are hard pressed to find easy solutions to a problem that stemmed both from Mother Nature and our own hubris.

In meetings following high water levels in 1997 and 1999, Idaho Department of Water Resources Director Gary Spackman recalled elected officials asking, "'Why did you let us do this to ourselves?'" This time, Spackman and his colleagues have some possible answers addressing a question they feel is more relevant: "How did we do this to ourselves, and how can we stop?"

First Boiseans need to change how they think about the Boise River, and federal agencies need to help them do it. According to IDWR, too many people see the river as a recreational or economic asset, often forgetting it's also a force of nature. Floods are seen as inconvenient rather than dangerous; a mistake that could be detrimental.

"Water changes... it's a living thing," said hydrologist and Idaho Water Supply Committee Chair Liz Cresto, "It's not a pipeline or a concrete channel. People tend to forget about that."

Specifically, they forget when building—according to Boise Floodplain Administrator Hal Simmons, there are around 1,000 homes and 500 businesses on the Boise River 100-year floodplain.

Spackman agreed with Cresto, adding the U.S. Army Corps of Engineers, which controls the river system during flood season, could change its messaging to help people understand the danger.

"[The Corps'] public outreach doesn't indicate the level of concern people should have when confronted with [flood] conditions," Spackman said. "People need to realize this is about much more than not being able to walk on the greenbelt, or not being able to float the river. The real problem is that we could have water in homes, in businesses, in Boise State and all kinds of places.

"The message," he added, "is that no matter what we do, they [the Corps] will save us. But one day there will come a year when that does not happen."

This year came close to being the one when the river overcame the Corps' abilities, and officials across the board agreed Mother Nature threw a curveball.

"If we had 20/20 foresight, we would have started releasing water sooner, but we didn't know to do that because until the first of February we were so normal snowpack-wise," said Brian Sauer, supervisory civil engineer of hydrology for the Bureau of Reclamation. "Then we got such a strong-building snowpack in February that we went into flood control mode. ... We just got an incredible amount of snow."

When spring hit, that incredible amount of snow became an incredible amount of water. Only relatively low precipitation and cool temperatures in May—combined with agency efforts—kept the river in check.

"[The Corps] were behind the rule curves almost the entire flood control season," said Cresto. "At one point, they had only 200,000 acre feet in the reservoir to control 2 million acre feet of runoff."

That means the Corps had about 586.8 billion gallons of water, at 326,000 gallons per acre foot, with nowhere to go but down into the valley.

"I have no criticism for how the federal entities operated the reservoir," said Spackman. "They couldn't let the water out fast enough. They did the best they could."

The Corps is limited by the river channel capacity, which is too low to handle big releases like those necessary this year. Several solutions have been investigated by the IDWR board—including widening the channel, raising the height of dams on the river system to increase the size of nearby reservoirs and building a new reservoir—but high costs have kept plans hypothetical.

Another option is changing the rule curves (Corps guidelines for controlling water) so release happens sooner, leaving more space for runoff in the reservoirs. However ,Spackman doesn't think that will happen in the near future, and human interest factors make him unsure it should.

"The tension is that the reservoirs were built for a dual purpose: flood control and irrigation," he said. "And we fight and defend that storage of water. ... I don't want those reservoirs empty all winter long if statistically you can't defend it. So, if the Corps starts keeping those things empty for a longer period of time I'm going to be writing letters to the Corps and the Bureau [of Reclamation], saying, 'What are you doing? You're jeopardizing the irrigators' storage in favor of some remote chance of something happening.' But that remote chance will come around, and they have to balance those interests."

The Corps is reserving judgment for now; according to Corps Public Affairs Specialist Gina Baltrusch, "There won't be a completed after-action report on this for quite some time."

State and local agencies, it seems, have ground into temporary gridlock trying to find a win-win solution to prevent Snowpocolypse II. With both Mother Nature and human nature stacked against them, the reevaluation period could be a long one.



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