Gauge reading 101...
Posted by:
pwsisk0 (IP Logged)
Date: November 13, 2009 07:53PM
I like the lost art of figuring out the logistics. Where to put in. Where to take out. What to do if a rock slide keeps you from your favorite run. Most importantly, will it be at a good level after it rains.
We're spoiled with online gauges. USGS gauges especially with all the historical data that they store. And its just a click away.
With that, here's a basic case study in how I'm 100% certain that the Little and the Tellico will both be running on Sunday. And I've known that since Wed. without a doubt.
First, you have to know what season you're in. This year the water tables are steadily building up with all this rain. Things are consistently holding a little longer. There was a big rain event the beginning of Nov. This last rain event was even bigger.
So I like to go to a gauge and pull up the table view of data. Then, I dig back and look at when the river was at a given point...say 3' on the Little gauge. Then I look at how long it took for it to get below 2.5' on its way down. Last time, that was 3 days. Since its still over 3'...then I know it will be running good for at least 3 more days.
For the Tellico, its a usgs gauge and has history, you can do the same thing. Comparing how long it took 12 days ago for it to drop from 2.25' to 1.5'....it will absolutely be there on Sunday.
Make sense? If not, I can explain.
Knock on wood, this has been an incredible fall for water. I remember several years ago (2004?) when the Tellico was basically runnable all of January and February. The slope of the graph basically leveled off at the minimum. Same for Little. I hope that happens again this year.