It means they all boogee up the clearwater to avoid the temps of the reservoir. A good portion of the Salmon, Snake and GR fish spend time in the lower Clearwater. The fish then hightail it to the other tribs when the snake stops spewing molten lava water.
The warmer the snake is, the more A's that will move into the Clearwater to seek refuge. The sooner they go in there, the more likely they are to move around the system more than just in the very lower reaches. Its been a cool spring and early summer.
OK, I thought they stopped moving when the Snake gets warm. Yeah, that would be nice if they move upstream of the Stink Hole. I talked with someone last Sept. when I was there who ran a boat up from near the mouth, and they said the river bottom down in the slack water - lower than I can fly fish - was carpeted with steelhead cooling off.
There is a fine line between the snake being too warm for them to leave the confines of the resevoir. The key is the Snake being just cool enough for them to enter the snake then the fish escaping to enter the CW for better conditions.
Dworshak reservoir flows play into these temps too... I know the feds are obliged to try and cool the LSR reservoirs with some water from Dworshak. Not sure if they have drafting down the reservoir yet. Probably not... I think this starts on August when LSR reservoirs get really hostile for steelhead and fall chinook.
What's this 1300 ahead of last year!! hey, I thought this was the washingtonflyfishing.com website. Here's something to wet your lines. I've been charting passage over Bonneville since 1997, full year counts (Jan 1 - Dec 31) are only available back to 2001. 2010 to date passage (as of 7/18) over Bonneville is 117,958 (all steelhead and the recent wild % are nearly 50%). Passage as of 7/18 in 2009 was 47,042, that means that so far this year we have 70,916 more steelhead over Bonneville to same date last year (71% more than 2009). The best year recorded, prior to 2010, was 2001 when passage to date was 98,568. So, here we sit with 19,390 more steelhead in the Columbia above Bonneville dam, than previously recorded. H'm, to me that means "get out your spey rod and fish everything!!", we may never see this again. Movement up the Columbia is clearly temp related. The Columbia is way cool and the fish are cruisin' up in big numbers...ther're not catching squat in Drano. If the Columbia warms most tribs will be full of fish. Enjoy yourselves boys, I'm gonna!!!
Here is some current news on temps and the relation of Dworshak reservoir in keeping Lower Granite reservoir from turing into a large caldron of steelhead stew. Not an exact answer to your question but it may help.
RIVER MANAGERS RELEASE DWORSHAK WATER TO HOLD DOWN SNAKE TEMPS AT LOWER GRANITE
Posted on Friday, August 06, 2010 (PST)
Salmon and hydro managers decided Wednesday to increase the flow of cooling water from
Dworshak Dam's reservoir for three days in anticipation of what could well be the last heat
wave of the season in the southeast Washington/west-central Idaho region.
The goal of the operation is to manipulate summer flows from the reservoir's depths in such
a way as to hold temperatures downstream at the lower Snake River's Lower Granite Dam
below 68 degrees F. Dworshak is located on the North Fork of the Clearwater River, which
flows into the Clearwater and shortly thereafter into the lower Snake near the upper end of
Lower Granite's reservoir.
Temperatures above 68 degrees can be unhealthy for coldwater fish such as salmon and
steelhead who are swimming to and from the Pacific Ocean.
So far so good. The dam's tailwater temperature for the three days ending Thursday hovered
67 degrees, plus or minus a tenth or a degree or two, and at no time this summer has the
temperature risen above 68.
As of this morning (Friday), 46.1 degree water from the North Fork was crashing into 76.6
degree water in the Clearwater, as monitored at Orofino, Idaho just above the confluence.
That water then joins the Snake, which was at 73.1 degrees, as measured at Anatone just
upstream of that confluence and downstream of the Hells Canyon Complex of dams on the
During a Wednesday meeting of the Technical Management Team, NOAA Fisheries' Paul
Wagner said that the Fish Passage Advisory Committee recommended that outflows from
Dworshak be increased from about 12,000 cubic feet per second to 13.5 kcfs.
FPAC is a technical advisory group made up of federal, state and tribal members. TMT is
made up of federal, state and tribal fish and hydro managers and is charged with adjusting
hydro operations with the aim of improving survival of salmon and steelhead stocks that are
listed under the Endangered Species Act. There are 13 such stocks in the Columbia-Snake
river basin, including four in the Snake drainage.
The forecast is for air temperatures at Lewiston in the 95 to 98 degree range through the
weekend and then some cooling is expected, Wagner said. More hot weather is possible,
but becomes less likely with each passing day.
The TMT discussed when to turn down the Dworshak spigot -- today, Saturday or possibly
Monday. All parties eventually agreed to drop the outflows from about 13.5 kcfs to "full
powerhouse" flows at the end of the day Friday to conserve as much water as possible for
the rest of the season. The powerhouse capability now is about 9.7 kcfs but increases as the
reservoir level drops to as high as 10.5 kcfs.
The 2008 Federal Columbia River Power System biological opinion calls for a drawdown of
the reservoir from full pool, 1,600 feet elevation, during the summer to 1,535 by Sept. 1, and
then to 1,520 by the end of September. The BiOp offers prescriptions for improving the
survival of listed salmon and steelhead.
The reservoir elevation dropped from 1,592 feet on July 15 when outflows were first
increased to above full powerhouse to 1,566 by Friday morning, Aug. 6. The elevation has
dropped by nearly three feet since outflows were increased Wednesday.
The keys now are the weather -- air temperatures and precipitation. If the weather heats up
again and stronger Dworshak outflows are required, the cache of available water would be
greatly reduced and would likely require later reductions to below full powerhouse, the Corps'
Steve Hall said. Increased inflows would be helpful, but August is a month that typically
yields little precipitation.
Jerry, that's exactly what happens on the upper Rogue. Right now the out flow from Wm Jess dam is about twice what it would be normally. And as noted above the C or E's are taking water from the bottom of Lost Lake as there's at least a 20 degree difference 'down deep' to surface temperature.