September 16, 2011 - Bend Bulletin - Where's all the water?
Sep 21, 2011
Where's all the water?
‘Precarious state': Construction consequences raise concern for stream below Shevlin ParkBy Nick Grube / The Bulletin
Published: September 16. 2011 4:00AM PST
Last weekend, Bend residents Mike Tripp and his wife went on a hike along Tumalo Creek downstream of Shevlin Park. What they found startled them.
Below the Tumalo Irrigation District diversion that sends water to Central Oregon farmers every growing season, the creek had been dammed and a backhoe was parked in the dry stream bed.
There were dead fish on the rocks and the only water flowing below the dam came as a trickle from a large pipe.
“I was angry that the water wasn't there,” said Tripp, who's the conservation chairman of the local branch of Trout Unlimited. “It was yet another example of people just not valuing the creek.”
He later learned that the dam and other equipment were part of a state-sanctioned construction project being performed by the district, and that the fish kill was a consequence of this temporary disruption of the stream flows. But that knowledge didn't alleviate his concern about the lack of water in Tumalo Creek. If anything, it heightened that concern.
“It's just a reminder that the whole creek below the diversion is in a precarious state with this minimal flow that's there,” Tripp said.
Tumalo Creek, which flows into the Deschutes River, provides a cold-water habitat for fish.
That cold water also helps cool the Deschutes, which sometimes exceeds state water quality standards for temperatures during the summer. Higher water temperatures can be lethal for fish and other aquatic life.
Because of Tumalo Creek's importance to the health of the Deschutes River, a lot of attention — and money — has gone toward restoring habitat and improving stream flows in the cold water tributary.
The city of Bend's controversial $68.2 million Bridge Creek water project has also put Tumalo Creek in the spotlight. Bridge Creek pours into Tumalo Creek, and the city's project will invariably affect flows in the stream.
The only view many people have of Tumalo Creek is above the irrigation district's diversion point. It's something they see while jogging through Shevlin Park or hiking to Tumalo Falls, places where the water flows with relative abundance.
Tumalo Irrigation District takes most of Tumalo Creek's water during the summer. The city of Bend is the next largest user, though it's a fraction of what the district takes.
Some water is required to stay in the stream after it passes Tumalo Irrigation District's diversion point, and the Oregon Water Resources Department monitors this flow with a gauge. In August, the amount of water upstream of the diversion — what most people see — can be around 10 times what it is downstream. The district is replacing that gauge with one that will more accurately monitor flows in the creek. It also will be designed to improve fish passage because the current gauge does not meet current Oregon Department of Fish & Wildlife standards.
“It's not a requirement for Tumalo Irrigation District to have this gauge there,” OWRD Regional Manager Kyle Gorman said. “But for the state of Oregon to properly measure and manage the water in Tumalo Creek it's needed.”
Tumalo Irrigation District has had problems over the years making sure the proper amount of water has been left instream. Gorman said part of the reason for this was “crude” technology at its diversion point that has since been improved. Another reason is related to the creek's flows. The water comes down the stream in what Gorman describes as a diurnal fluctuation. That means the flow can be heavy at certain times of the day — such as if there's a lot of snowmelt — and light at other times.
To account for this, the Tumalo Irrigation District would need to adjust equipment and settings at the diversion to make sure the proper amount of water remains instream.
“On occasion we'll see the flow drop down below what it should be but in a matter of hours we'll see that come back,” Gorman said. “It's on a very rare, very infrequent case. The district puts every effort that it can into making sure that instream water right is there ... And the majority of the time there is excess water there than what is required.”
As a part of the gauge construction, the district installed a bypass pipe to make sure water still flows down the creek while work is under way. This pipe is supposed to dump about five cubic feet of water per second into the stream, but so far this hasn't been the case.
In fact, when Tripp first saw the creek, he was able to measure the flow with a five gallon bucket, something that would be nearly impossible if the district were meeting the five-cubic-feet-per-second target.
Tod Heisler is the executive director of the nonprofit Deschutes River Conservancy, which works with irrigation districts — including Tumalo Irrigation District — to help restore flows to creeks and streams.
Like Tripp, Heisler noticed the low flows in Tumalo Creek over the weekend and said it was much different than what it would be under normal circumstances. Heisler said his group contacted the district to inform it of the dry creek bed and low flows in its bypass pipe. He said the Conservancy encouraged Tumalo Irrigation District to fix the problem, both in the interim and the long-term.
“They need to serve the river the same way they serve their patrons,” Heisler said of the irrigation district. “It is kind of tricky, but that's the bottom line. The creek needs to be served the way their patrons are.”
Tumalo Irrigation District admits it's had difficulties with the recent gauge construction and allowing enough water to pass through its bypass pipe.
Jon Burgi, who is the lead engineer on the project, said the district is making up for the lack of flow by dumping more water in the creek about a quarter mile downstream. That amount of water, he said, is about twice what is supposed to be coming from the pipe.
Burgi also noted that the district has been involved in a number of projects that have improved water flows in Tumalo Creek below its diversion, including piping its canals so more water is left in stream. He said the new gauge — which costs around $40,000 and will take about three weeks to build — will simply improve the district's ability to make sure water is making its way downstream.
“The project is for a total benefit to the system,” Burgi said. “When we construct something, things don't work as well (at the beginning) when we know they'll work better later. It's kind of like when you close one lane on a highway for construction. Things will work better in the future.”
Nick Grube can be reached at 541-633-2160 or at firstname.lastname@example.org.
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