[Lugan]

I think I know the Yakima basin well. But I just noticed what appears to be a clear discrepancy between the flows at the Keechelus, Kachess, and Easton dams.

Right now Kachess outflow is 193 cfs: http://www.nwd-wc.usace.army.mil/nws/hh/basins/data.html?yak+kac

Keechelus is 653 cfs: http://www.nwd-wc.usace.army.mil/nws/hh/basins/data.html?yak+kee

If I'm not mistaken, Kachess + Keechelus flow into Lake Easton. So the outflow of the Easton Dam should register about 850 cfs since Lake Easton is very small and can't absorb a ton of inflow while restricting outflow (or vice-versa).

Yet Easton outflow registers about 235 cfs: http://www.usbr.gov/pn-bin/graphrt.pl?easw_q

Question: Where is the missing 615 cfs?

I've been tracking this dicrepancy for a few weeks since first noticing it. Granted, the first two flow measures are from a different source than the third, but that seems irrelevant as a cause. Maybe one of the guages is mis-calibrated or broken? Other explanations?

 

[Greg Smith]

The water goes into a large irrigation canal called the main canal. It feeds the upper Kittitas Valley.

Greg

 

[Split Bamboo]

Local subterranean Hotspot causing massive evaporation!

Seriously, some guesses....

Is there any irrigation/diversion up there? 615 cfs would be a big diversion, but that's my guess.

Another thought, is there a timing difference on the measurements...or are you allowing for the time needed for the flow to move downstream? If you have observed this irregularity over a long period of time, I doubt that could be it.

Gauges can get blocked and clogged, but I would think on such an important, accessible river this would get fixed fairly quickly.

 

[Lugan]

Greg, are you sure that main irrigation canal starts that far upstream (above Easton)?

Split Bamboo - All good guesses, but I've noticed this for far too long, including before irrication season (which may render Greg's explanation moot).

 

[riseform]

This is a great link for the Yakima (KRD) irrigation. http://www.fairpoint.net/~krd/index.htm
After reading the fact page, check out the maps if interested (also fascinating to look at this project via Google earth).

 

[Trout Master]

A quick look on google earth will show you the canal Greg is taking about. If you have ever floated the river between south clelum and thorp, it will dump onto you if it is flowing fast. Another thing I have noticed lately is when someone gives an answer to a question the person asking the question blows it off. WTF.

 

[InEaston]

The canal starts right in the same vacinity as the Easton dam. Also, I live on the river below the dam and the river is up, but clarity is good, the hatches are sporadic and inconsistant. Lots of big black ants(flying and land rovers).

 

[Mumbles]

Is that upper river irrigation what comes down the huge concrete "water slide" on the right right at the Bristol ramp? I was told that when the water is shooting down that sucker it comes about 3/4 across the river making passage far left the only option. I can't wait to see that in action.

 

[Lugan]

A quick look on google earth will show you the canal Greg is taking about. If you have ever floated the river between south clelum and thorp, it will dump onto you if it is flowing fast. Another thing I have noticed lately is when someone gives an answer to a question the person asking the question blows it off. WTF.

Thanks everyone for your answers, that explains it. Riseform, that's a great link. Amazing that after a few hundred days on the Yak I haven't crossed paths with that canal, though from the maps it seems to be well away from the river most of the time.

Hey Trout Master, I wasn't blowing Greg's answer off. Greg's answer was short and lacked specificity, so I asked a follow-up question to help figure out exactly where this canal is. WTF back at'cha.

 

[Trout Master]

Lugan, no you didnt blow it off, but it's the way you replied to it . Mumbles your are correct the water shoots about 3/4 of the way across, Lugan may doubt this though as he has a few hundred days floating it and has never seen it.

 

[Mumbles]

I've only been through there with a slight trickle, but if it is roaring in summertime I hope to see it soon. Do any of the rubber hatchers helmet up and take that slide ride?

 

[riseform]

For Mumbles...

 

[Mumbles]

That is a hell of a waterslide. Makes the Great Wolf Lodge look puny. Thanks Riseform. I'll be following the directions on that sign for sure.

 

[Alex MacDonald]

Man oh man--cowabunga, guys!!!

 

[Tyler Sadowski]

That flume is nasty. Years ago I saw it kill a guy in a tube. Sad day that was, having to fish and be on the look out for a body.