Piping project could help fish return to Middle Deschutes
Two decades ago, Tumalo Creek ran dry downstream of Shevlin Park in the summer, as the Tumalo Irrigation District diverted water to supply farmers.
Things have improved a bit for the lower section of the creek since then, as projects to replace open canals with pipes have made sure that there’s at least 6 cubic feet per second, or more than 3.8 million gallons per day of water, even during the warmest, driest months of summer.
But now water managers in Central Oregon are working on plans that could quintuple that amount, through replacing even more miles of canals with pipes and possibly relying more on a different source of water to irrigate Tumalo agricultural land.
And having more cold water in Tumalo Creek would not only help fish there, but would cool down the warmer Deschutes River where the two waterways converge north of Bend.
“We really need as much Tumalo water as we can get because everyone has increasingly identified temperature as our significant problem,” said Tod Heisler, executive director of the Deschutes River Conservancy, which is working to set up and find funding for the project. “We want to put as much of that into the Deschutes as we can; we need to maximize the water from Tumalo.”
The Oregon Department of Fish and Wildlife has done surveys for trout in the Middle Deschutes, between Bend and Lake Billy Chinook, and sometimes has a hard time finding any, said Scott McCaulou, program director with the Deschutes River Conservancy.
“The Middle Deschutes should be pretty good habitat for native redband trout, but right now, because of the flow situation and the temperature situation, it’s a pretty depressed situation,” he said.
But the Upper Deschutes Watershed Council has done a study that shows high flows from Tumalo Creek can cool down the Middle Deschutes. For example, on one day in June 2006, 170 cubic feet per second, or cfs, of 52-degree water from Tumalo Creek flowed into Deschutes River, which was at 102 cfs and 67 degrees. The water downstream of the convergence was 59 degrees.
The state Department of Environmental Quality is working on a computer model to see how much of a difference 32 cfs of that cold, Tumalo water would make, McCaulou said.
That’s the number that ODFW has said is needed to bring the conditions up to speed for fish in Tumalo Creek in summer, and the target for the current set of water conservation projects.
But to get there takes multiple steps and is projected to cost $26 million.
A winter start
This winter, if the Oregon Watershed Enhancement Board helps fund the first stage of the project, the Tumalo Irrigation District will start on work to pipe about eight miles of the Tumalo Feed Canal as it flows northwest from the creek to Tumalo Reservoir, said Elmer McDaniels, secretary and manager of the irrigation district. Because water seeps out of the canals into the fractured basalt rocks below it, piping will allow the district to divert less water from the creek.
“The emphasis is on trying to improve the reliability of water to our water users and improve Tumalo Creek,” McDaniels said.
The project will conserve about 20 cfs of water that otherwise would have filtered through the ground, 12 cfs of which will be permanently returned to Tumalo Creek, McCaulou said. The remaining 8 cfs of conserved water from the piping project will be permanently protected in the Deschutes River, from which the Tumalo Irrigation District also diverts water.
That piping project will be done in stages and will hopefully be completed in 2010, he said.
The second piping project involves the Central Oregon Irrigation District, a separate irrigation district that serves customers north of Bend.
Starting in October 2009, the Central Oregon Irrigation District is planning to pipe more than two miles of the Pilot Butte Canal as it goes through Juniper Ridge, a project that will also generate power from a small hydro facility.
That project is expected to conserve about 19 cfs of water, but instead of simply returning the water to the Deschutes River, the river conservancy is proposing to do something a little more complicated.
The organization will buy the water rights from the Central Oregon Irrigation District and then give 15 cfs of the Deschutes water to Tumalo irrigators. In exchange, the Tumalo irrigators would leave an equal amount of the cold Tumalo water in the creek.
“We’ve traded up, in essence, in the ecological value of the water we’re putting instream,” McCaulou said.
The plan isn’t finalized yet — the parties must make sure that the canal that pipes water from the Deschutes to the Tumalo system can handle the increase, and McDaniels said the irrigation district has concerns about the effects of warmer water on the infrastructure.
But the district has agreed to investigate the feasibility of the idea, and if things look good, move forward with the switch, Heisler said.
If it all works out, he said, it would complete a significant amount of effort that has gone into restoring Tumalo Creek, adding to the habitat restoration work done by the watershed council and fish screens that the irrigation district has put in at their diversions.
“This would really be a crowning achievement,” Heisler said.