This article was published on: 09/17/15 12:00 AM
By Gail Snyder
A recent Bulletin article referenced “natural low flows” in the Deschutes River. That description might be misleading. Under natural conditions, flows in the Deschutes River do not rise and fall dramatically. In fact, the river was called “the Peculiar River” because its flows were remarkably stable all year long. (The Metolius River is another example of a river with stable year-round flows.)
That changed when dams were put in to control the flows — flooding the river during the irrigation season and starving it of water in the winter months.
The artificially high flows imposed on the Upper Deschutes since the construction of Wickiup and Crane Prairie dams are equivalent to having a 25-year flood event every year during the irrigation season.
As for low flows during the winter “storage season,” the minimum requirement below Wickiup is a meager 4 percent of the natural low-flow levels. Again, under natural conditions, flows were near constant all year round.
One of the consequences of these altered flows was the fish kill that caught our attention in 2013. That event was not an anomaly. Fish kills due to dewatering of the river were documented in 1947 by the Oregon State Game Commission. The report also noted that waterfowl and mammals suffered, and sports fishery and river productivity declined when the river was repeatedly dried then flooded.
The artificial high and low flows in the Deschutes River have exacted an economic, aesthetic and environmental toll. Author and fly-fisherman Bruce Bischof described the river as being a “mere shadow of itself.”
He wrote: “In the 1970s and ’80s, the Upper Deschutes was still considered one of the finest blue ribbon trout streams in the Western U.S.” That is no longer true. In Bischof’s words, “Although during peak summer flows, the river is beautiful by visual standards, it is virtually sterile by healthy stream standards.”
The Upper Deschutes is not the only reach of the river in trouble. Nearly 90 percent of the streamflow of the Upper Deschutes is diverted through canals during the irrigation season. That leaves the Middle Deschutes, between north Bend and Lake Billy Chinook, with a dramatically reduced amount of water and impaired water quality.
If all of this sounds hopeless, it’s not. We can support agriculture and have a healthy river — but not without reducing the waste in our current irrigation system.
A 2001 U.S. Geological Survey report noted that sprinkler irrigation is the most efficient and flood irrigation the least efficient irrigation method. The difference is stark.
In areas where flooding is the primary method of irrigation, the efficiency is as low as 43 percent. That is, 57 percent of the water is wasted. One-third of irrigation in Central Oregon Irrigation District (in Deschutes County) is flood irrigation.
There is a good example of sprinkler use just to the north of us in Jefferson County. There, sprinklers are the primary irrigation method; the efficiency is as high as 94 percent.
These farmers irrigate more land with substantially less water. And while agriculture makes up about 1 percent of Deschutes County’s income, in Jefferson County, agriculture constitutes 10 percent of the economy.
We are wasting precious water in Deschutes County with less overall economic benefit. It doesn’t have to be this way. Farmers in Jefferson County have demonstrated that wise water use can support a healthy agricultural economy.
The Deschutes River is the lifeblood of Central Oregon; our current and future economy and quality of life depend on it.
Wasteful irrigation and damaging reservoir management practices are harming the health of the river and all who depend on it. We can have both agriculture and a healthy river, but to ensure the long-term health of the river for all, we must reduce the amount of water taken out for irrigation. We have to leave the water in the river.
It’s time to restore the river to its true natural flows.
— Gail Snyder is program director for Central Oregon LandWatch. She lives in Bend.