This article was published on: 11/23/08 12:00 AM
Untroubled waters
Thanks to winter’s heavy snowpack, Wickiup won’t need as much refilling
By Kate Ramsayer / The Bulletin
Published: October 14. 2008 4:00AM PST Rob Kerr / The Bulletin
A little more of the riverbank along Mirror Pond and Deschutes River south of Bend might be showing in recent days, as water managers have started releasing less water from area reservoirs.
“The irrigation season is coming to a close,” said Kyle Gorman, south central region manager with the Oregon Water Resources Department.
And as irrigation districts shut off their canals in the fall, when crops are harvested and plants get less thirsty, less water is released from Wickiup Reservoir and other reservoirs in Central Oregon.
But this summer, irrigators didn’t need to use much of the reservoirs’ stored water, because a heavy snowpack last winter provided much of the water for irrigating fields through natural runoff.
That means it won’t take as much to fill up the reservoir this winter — leaving more in the river, which improves habitat for fish.
“It was just a really great year,” Gorman said.
The snowpack that built up over the winter was more than 150 percent of average at the typical peak time, he said, and it started melting right when ranchers and farmers needed water the most.
“Timing-wise, it was great, because when irrigation demand was here, we had good runoff,” Gorman said.
And so irrigators could take more of the natural river flow, without depending on water that had been stored in reservoirs, said Steve Johnson, Central Oregon Irrigation District manager.
Plus, the spring was relatively cool and wet, he said, so there wasn’t a big rush for water early in the season.
“There’s a lot more water staying in the reservoirs,” Johnson said.
Wickiup Reservoir is currently about half-full, Gorman said. There’s 92,000 cubic feet of water behind Wickiup Dam, while the average at the end of September is only about 62,000 cubic feet.
The extra water in the reservoir means that more water can be released from Wickiup through the winter, when managers typically are storing water for the next summer’s irrigation season.
“We don’t have a number, but it will be well above the minimum out of Wickiup,” Gorman said.
The minimum flow is 20 cubic feet per second, and by the end of the week, once most of the irrigation canals shut off, the flow out of Wickiup Reservoir will probably be around 10 times that. The amount that water managers release will vary through the winter as they get updated forecasts on how much rain and snow will fall, but they already have a head start toward the goal of filling the reservoir by April 1.
“Even if you have an average or slightly below average winter, you’re still going to be able to fill up Wickiup,” Johnson said.
Kate Ramsayer can be reached at 541-617-7811 or kramsayer@bendbulletin.com.