This article was published on: 04/11/20 12:00 AM
By Yancy Lind
“Frog, fish populations under threat in the Upper Deschutes,” reported on the dire shape of the Upper Deschutes river (The Bulletin, March 30). For decades, the Upper Deschutes has had unnaturally high flows in the summer when water is released from reservoirs to meet irrigation demands. Summer flows are three times the natural levels and have scoured the banks, widened the channel, and filled spawning beds with silt (as well as Mirror Pond). In the winter, the reservoirs are refilled, and the river is reduced to unnaturally low flows, exposing the riverbed to freezing temperatures, and killing fish, aquatic plants, insects, and amphibians.
The endangered Oregon spotted frog resides in the Upper Deschutes, requiring irrigation districts to come up with a “habitat conservation plan” (HCP) that will limit further “take” (killing) of the frog. There is fierce debate around the plan’s adequacy and timing, but at least there is discussion.
The Middle Deschutes suffers greatly from unnatural flows but is not part of the discussion. This section of the river extends from the last major irrigation withdrawal at the North Canal Dam near the Riverhouse in Bend down to Lake Billy Chinook.
As stated in the article, the Upper Deschutes below Wickiup Reservoir historically had very stable flows, rarely dropping below 600 cubic feet per second (CFS). Farther down river, the Deschutes is met by the Little Deschutes as well as by the Fall River and Spring River. With these inputs, the Middle Deschutes in Bend was historically at least 1,000 CFS year-round.
It grew even more when joined by Tumalo Creek, which is now also reduced by irrigation withdrawals.
Today, the Deschutes below North Canal Dam fluctuates from levels as low as 65 CFS in the summer to an average of 600 to 800 CFS in the winter. There are more frequent and drastic changes in water levels in the middle river than in the upper. You can see this by going to www.usbr.gov/pn/
hydromet/destea.html, clicking on “DEBO”, and then “Water Year Graph”.
While the habitat for fish and wildlife in the Middle Deschutes has been severely damaged from extreme water fluctuations, there are no endangered species in this section of the river. (Bull trout went extinct in the Deschutes above Big Falls decades ago.) As a result, irrigators are not required to address damaging environmental problems in the Middle Deschutes and have no plans to do so.
To be fair, the irrigators have recently agreed keep flows at a minimum of 250 CFS in the winter. In past years the river would get well under this level. Regardless, extreme low flows during summer irrigation season eliminate any benefit of more stable flows in the winter. Like us, aquatic species need to be able to breathe all year, not just in the winter.
There is heated debate on the irrigation district’s draft HCP. That debate is about what sections of canal to pipe first, how to prioritize main canal piping versus on-farm efficiencies and inter-district transfers, as well as the speed at which this must occur. All of these will slowly restore some amount of water into the Upper Deschutes. No one, however, is talking about how to help the Middle Deschutes.
We taxpayers are already paying to modernize irrigation district infrastructure for the benefit of private landowners. The final bill is projected to be close to one billion dollars and we will pay most of it. The public owns the water, we are paying for it, why can’t we demand that the Middle Deschutes be restored, as well?
Yancy Lind lives in Tumalo and blogs
at www.coinformedangler.org