Boise Valley Fly Fishers
Since 1971


Lower Owyhee River High Water

17 Mar 2024 7:34 PM | Troy Pearse (Administrator)

The Owyhee drainage has had two great back-to-back snow years. Last year the reservoir was so low that it didn't fill, but this year is a different story. We had great carry-over in the reservoir and with all of the snow this season the reservoir is going to over-fill, which means the lower Owyhee river will get some much needed flushing flows.   Flushing flows are particularly important on the Owyhee because over time fine sediments have accumulated from dry side channel blowouts, which is hurting the bug habitat and trout spawning habitat. Figure-1 below shows the reservoir levels and you can see how much more water we have this year compared to last. 

The Owyhee Irrigation District has started ramping up flows and many are wondering how high they will go, and how long they will be too high to fish. To make an educated guess, let's take a look at the reservoir carryover, snowpack and flows from 2017 and 2019, which were the last 2 high water years.

Here is the snowpack graph for the upper Owyhee drainage.  (You can click on any graph to get a full-size version.)

  • The snowpack this year is one of the highest on record (black-line), and is well above the snowpacks from 2017 and 2019 (yellow and green lines).
  • The snowpack in 2023 (purple line) was impressive. We had a cool wet spring and the snow continued to accumulate in the mountains.
  • 2022 had a meger snowpack and is shown in dark green for comparison.

Although the reservoir didn't fill last year,  it did come up 31 feet between mid-March and the end of June.  Right now the reservoir is 13 feet from full, and the snowpack potential for this year is very similar to last year, which means there could be an 18 extra feet of water to spill!  (Note: Reservoir fill rates aren't linear, so this isn't exactly accurate...but you get the point. There is a lot of extra water up in dem der hills! ) 

Comparing the current Owyhee reservoir level to 2017 and 2019 (the last 2 times we had high flows), you can see that the reservoir elevation this year is similar to 2017, and our runoff this year hasn't even started.  

Given that the Upper Owyhee drainage has significantly more snow this year than it did back in 2017, I would expect we will see flows at or above what was released in 2017.  Here is a look at spring flows from 2017, 2019, 2023 and so far in 2024. Hold onto your hats, I think we have some high water coming soon!

Don't worry about the fish getting blown downriver.  Unlike the Boise River which stays in bank until 7,000cfs and gets high river velocities, the Owyhee jumps out of bank around 2,000cfs, spreads out and the river velocity don't increase as much so trout have plenty of places to get out of the flow in the willows.

When the river comes down, fishing will be even better than before. The bug hatches will improve, and I expect we will have some crappie in the river to chase as well. There is no way to tell, but I think the high water might also help clean out the Saprolegnia fungus that has been infecting brown trout after they spawn. Keep yer fingers crossed!

As the reservoir gets close to filling they divert some water through the Dam Ring Gate Spillway, which locals call the "Glory Hole". If you haven't seen it, it's worth taking a drive up to see. Here is a little more info about it.  

Copyright © BVFF 2013 ---. All Rights Reserved.
The Boise Valley Fly Fishermen, Inc is a non-profit corporation organized under section 501(c)(3) of the Internal Revenue Code, incorporated in the State of Idaho
Powered by Wild Apricot Membership Software