Central Oregon water reservoirs to drop to low levels
Aug 06, 2016
Reservoirs in the Deschutes River Basin are at similar levels as last year
By Ted Shorack
Water managers expect reservoirs to be very low again at the end of irrigation season in October, even though the region’s snowpack was much better compared to the previous winter season.
After a mild winter with limited precipitation in 2015, Central Oregon irrigation needs drew down Wickiup Reservoir to its lowest level in about 20 years.
At the end of irrigation season this October, the reservoir is expected to be at about the same level as it was at the end of last year’s season.
“We’re extremely close to the same day as last year, and the trajectory is basically the same,” Jeremy Giffin, the regional watermaster for the Oregon Water Resources Department, said Friday.
Wickiup Reservoir can hold about 200,000 acre-feet of water. An acre-foot can submerge an acre of land in a foot of water. Water in the reservoir is monitored and released into the Deschutes River, where it is diverted by irrigation districts and delivered to water-right holders such as ranchers and farmers.
Giffin said as of Friday the reservoir has reached about 63,000 acre-feet and will likely drop to about 16,000 acre-feet by October, which was its level at the end of the 2015 irrigation season.
“Wickiup is going to end up exactly or very similar to last year, which is very low,” Giffin said.
The governor’s office granted drought declarations to 25 Oregon counties last year, including Deschutes, Crook and Jefferson counties. The dry conditions had an effect on this year’s supply. Wickiup Reservoir wasn’t completely refilled by the time irrigation season began in April and instead was at about 88 percent capacity.
“What we may have gained we lost by not having the reservoirs at capacity, so they kind of offset each other,” said Giffin. “We’re ending up with similar reservoir results at the end of the season.”
Deschutes River reservoirs were managed slightly differently this year as part of an agreement to help the Oregon spotted frog, a threatened species listed under the Endangered Species Act. More water was released ahead of irrigation season to provide higher water levels in the river for frog breeding.
Water has also been held back this year longer than usual in Crane Prairie Reservoir and Crescent Lake, which are north and south, respectively, of Wickiup.
Giffin said both Crane Prairie and Crescent Lake are expected to be drawn down quickly in the next 60 days. Crane Prairie was about 71 percent full as of Thursday, according to the U.S. Bureau of Reclamation. Crescent Lake was 67 percent full.
The natural flow from the Little Deschutes River has helped alleviate some of the demand from the reservoirs, Giffin said.
“We had quite a bit … so that kept us from drawing the upper reservoirs down to low,” he said.
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