Whitewater Forum: Tumwater gauge correlations and thoughts on levels
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Tumwater gauge correlations and thoughts on levels

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Category: General
Forum Name: Whitewater Forum
Forum Discription: Open Discussion Forum. Whitewater related subjects only
URL: http://www.professorpaddle.com/forum/forum_posts.asp?TID=15913
Printed Date: 20 Jan 2019 at 6:19am

Topic: Tumwater gauge correlations and thoughts on levels
Posted By: NateW
Subject: Tumwater gauge correlations and thoughts on levels
Date Posted: 12 Dec 2017 at 10:36am
Was debating with a buddy about Peshastin vs. Plain gauge for Tumwater last night. Ended up writing a long email to him based upon what I found looking at the levels from this year. Decided to CC a friend who is just getting into running Tumwater. Keep in mind that I'm a IV+/V- boater based on risk tolerance (job / 2 year old son / 39 years old). Thought some folks might like to read it as well:

Plain this summer:

Peshastin this summer:

Plain today:

Peshastin today:

On the way down - by the time it reaches the <3000CFS level on the peshastin gauge the contribution of the icicle/peshastin is pretty consistent. I know for a fact that ~900CFS Peshastin / 600CFS Plain is about my lower limit. The wall / chaos still go fine at those levels. It's mainly the dam rapid that gets really boney. When **** got out for the first time this summer the peshastin gauge was right around 1000CFS.

With that in mind I went and looked at the date span in March where the river came up for the first time:


There is a much larger differential there, which makes sense because there was a bunch of low lying snow. That seems like the time when you could think there is more water in the Tumwater than there really is.

1800CFS this Sunday would have been quite a bit more water than what **** has seen before. 1800 - 2500 CFS is a pretty fun level, for the dam -> red bridge level. It's definitely more of a bit water feel and you're going over the top of a lot of stuff at that point.

My experience with the levels goes like this reference Peshasin gauge:
30000 CFS - highest I've ever run Chaos. You can sneak superboof way on the right. I thought it was actually pretty easy at this level, but the off line consequences / holes start to look really gnarly. I know **** swam around these levels with **** once, and he swam a *long* ways. Keep in mind that **** didn't do much to swim to shore so that was his own damn fault.

2500 CFS - This is when I'm pretty comfortable running chaos - superboof goes really well at that level, but if you fu*k up you better roll up quickly before go over the next drop.

2200 CFS - Highest I've ever run the Wall. Pretty tricky at those levels - the move into the airplane turn is really pushy and maybe that's not the best line at those levels.

2000 CFS - The Wall - Airplane turn move seems pretty manageable at those levels.

POW - Only ran it a few times starting last year. ****'s level tolerance on POW is 1500 CFS - which seems about right if you're going to run the left to right line. The run on out POW is pretty boney at 1000CFS. I'd say that 1500 CFS - 900 CFS is a good range unless you want to do a lot of boat dragging on the runout.

For the relatively conservative boater I think that these levels can be an OK guide for when to run stuff:
2500 cfs chaos
2000 cfs wall
1500 cfs POW (not sure I'd ever consider running POW conservative)

Posted By: jP
Date Posted: 13 Dec 2017 at 11:50pm
well my take on the whole tumwater guage thing basicaly boils down to this:

Yeah, going by the Peshastin Guage gives you the Broad Brush One Stop Shop idea of what the whole Tumwater/Icicle/Playrun system is basically doing.
However, my experience is people go by that guage pretty much trying to make it sound like they ran Tumwater higher than they actually did to spice up them braggin rights. Haha I'm only partially serious.

Seriously though- and yeah its seasonal of course but during The Melt Icicle is pumping in A LOT of water between the two guages. So if you go by the Peshastin guage you are getting your info distorted by Ici. Its basically...yup. You guessed it. FAKE NEWS. Since the whole point is to MEASURE what you're boating on, to hopefully enhance your understanding of what's going on out there, most of the time it makes most sense to me to go by the Plain guage. Pretty sure its below the Chiwawa confluence I guess I could be wrong but if it was above that would throw it off. Chiwakum creek is the only trib I'm aware of between the Plain guage and the Tummy but it doesn't pump in a whole lot compared to say, Icicle.

So I've always advocated the Plain Guage for Tum.
Of course, I'm pretty sure Marco disagrees. Naturally, that would make him wrong.

Haha I'm just kiddin- jeeeez. lighten up PPeeps. Besides- if someone is capable of running that sh!t at 15,000 cfs or whatever he's into, does he really need to know which gauge is more accurate? Honestly its the discerning (cautious, timid, whatever) boater who needs to console himself with data who is going to have the incentive to dial in said data. Plain Guage all the way with a loose eye on the other ones.


Posted By: jP
Date Posted: 13 Dec 2017 at 11:58pm
Before there was any online or text delivered data from the Icicle guage, James the Brilliant and Talented Author of Professor Paddle devised a formula for loosely determining the flow of Icicle.

Subtract the Plain value from the Peshastin value. Take 75% of that difference value and there is a ballpark Ici flow. Now, Fuqua, who for many years was the "Mayor" of Icicle Creek may have called bullsh*t on that simple formula but I found it was roughly useful. He would get into lots of detail about Mountaineer Creek and the phase of the melt season arguing that the variablitiy found there made the whole 75% thing invalid but I still think its a useful way to conceptualize what's happening. For years now though we been hittin the Ici guage on the 41411 though and its been sweet.


Posted By: jP
Date Posted: 14 Dec 2017 at 12:00am
I do think its cool that you've taken a little time to think about flows and correlations to your experience. Some don't like to 'geek out' on that sh*t but I think Knowledge is power.


Posted By: NateW
Date Posted: 15 Dec 2017 at 7:16am
Just checking back into this thread - and realizing there is a far simpler way to look at this. During the summer boating season when most people are running Tumwater and using the Peshastin gauge, the icicle and peshastin creek are contributing somewhere in the range of 300-400CFS. If you're looking to get onto the Tumwater during another time of year and want to correlate it - just look at the plain gauge and add 400CFS.

I've been running Tumwater more this late fall because there is practically no skiing. When taking out boaters that are just getting into the Tumwater game I wanted to make sure I was taking them out at friendly levels.

Posted By: Sam_Graftton
Date Posted: 17 Dec 2017 at 2:42pm
I think the most accurate way to gauge Tumwater is to look at the Peshastin gauge and subtract the Icicle reading. I've been in Tumwater plenty of times in the spring when there's loads of snow and small tribs feeding the canyon, the same can happen in the autumn with big rain storms.

Also Chiwaukum Creek and Hatchery Creek come in at start of the Canyon below the Plain gauge, these tribs can be feed well over 1,000 CFS during peak season.

Icicle has an accurate CFS gauge that works on 41411.

Posted By: tiziak
Date Posted: 18 Dec 2017 at 8:34pm
A day on Tumwater is a day well spent, regardless of the gauge used.

Go get sick!

If you don't know where you are going, any road will get you there.

Daniel Patrinellis

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