Tailwater questions

[Kurt P]

Until about a year ago, my fishing was mostly limited to un-dammed mountain streams. The recent fluctuations in the lower Yuba flow (700cfs to >8,000cfs, back to 700 cfs within a few days) has raised a few questions.
Does this kind of fluctuation blow fish downstream and out of the system, or do they hunker down for a while, or doesn’t it effect the bite all that much? If they stay in the system, but the bite is off for a while, how long does it usually take until they exhibit their typical feeding patterns? Is it all just a matter of water clarity?
Finally, are there resources where one can find out if big changes in dam releases are planned (I know some releases have to be done emergently due to upstream runoff, but that couldn’t have been the case when I encountered high flow in the Feather’s low flow section last summer/fall).
Thanks,
Kurt

[RJSFLYTRIP]

With the large Yuba fluctuations the fish just hunker down. They find their favorite rock or seem and ride the extra water out. The extra water can put the bite off. Usually with decent flow changes of 1,000 cfs or more I usually give the fish about a day to get their bearings back. One thing I can tell you is that fish on the Yuba don't go into complete turn off like mode like the rainbows on the Lower Sac with a larger flow change. The water clarity issue is another great fishing mystery. Fishing in brown water with less than 2 feet of visibility usually results in really hard fishing. It would be like trying to eat in the dark for us. Pretty hard to eat when you can't see your food. If the water starts turning that dark olive or turquoise (steelhead) color then the fishing can be really good on the Yuba. Usually the less visibility in the river the more you are going to want to fish bigger and brighter fly patterns. Once the river is back to 3+ feet then the smaller flies can start being productive again. It seems like most flows on the valley rivers go up steadily rather than jumping huge amounts at one specific time.

Hope this helps to put all the pieces of the puzzle together!

Tight Lines!

[Bill Kiene semi-retired]

During very large floods I believe that both the Lower Yuba and Lower American Rivers exceeded 100,000 cfs for a short time.

That really screwed up the Lower Yuba for a few years.

[Paul B.]

Remember the pictures posted in early 06? Every time I visit the Parks Bar area I think about how high the flows were. A screwed up river it was. You have to wonder how the bugs made it too.

[bigtj]

Big bumps in flows usually hose the bite. I think what happens is the fish have to re-establish lies and are paying more attention to territoriality between each other than eating. Once they get back in a rhythm, they go back on the bite. I have seen it time and time again, for whatever reason when the flows go up, the bite goes off. There are probably temperature related effects, too. Whatever the reason, I prefer flows that have been stable for at least 2 days.

As far as "blowing fish out" I don't think that happens. Truly huge floods make it difficult for the fish to survive, because the food source is compromised, so there is mortality that way. However, I think there is always slower water for the fish to hang out in, they do no get "blown down" unless it's a catastrophic flood wave that develops in minutes, like when dam bursts or a flash flood, and that doesn't really happen very often.

[Kurt P]

Thanks for all your input everyone. That does clear things up for me, about as much as can be expected for something as mercurial (gosh I hope that's the right word) as fishing.
I can't wait to hit the Yuba again and stand on the river bank and try to imagine 100,000+ cfs hurling down the canyon. That must've been horrific! How could anything have survived that?
Good fishing,
Kurt

[Kevin Goding]

Big changes in flow shouldn't kill too many of our native fish, they are adapted to handle things like that because of spring runoff. Non-natives from non mediterranean climates won't handle big pulse events very well.

The exception to all this might be cases of extreme bedroll (where the majority of the substrate moves) it can cause big problems. For one, most of the inverts will not survive bedroll events, so food supply is decreased. Also, if all the instream habitat shifts, the micro habitats the fish are using to wait out the flow event could disappear and then I would imagine they do get blown downstream to some degree.