CFS vs Gauge Height Debate

[Gavin]

The gauge is just a tool. Might give you a clue but they are not a substitute for scouting or experience.

[Al Agnew]

Hey Wrench, just for fun I did a little checking on the Little Niangua, which happens to be one of the very few streams in the Ozarks I've never floated.  

First I looked to see where the gauge is located.  It's at the Hwy. 54 bridge.  Then I looked to see where the highest generally considered put-in is by Googling it.  Looks like the highest is only a couple miles above Hwy. 54.  But on the map, it doesn't show a whole bunch of creeks coming into the Little Niangua between there and LOZ.  And I know there aren't any really big springs.  So I figure whatever it's flowing at Hwy. 54, it probably won't be flowing any more than twice that much on the lower end before it runs into the lake.

Having established that, I then went to the USGS gauge for it (forget about the apps, they don't tell you nearly as much as the real gauge does, so figure out how to get the real gauge to load...I never have any problems with it).  What I did was go to the gauge site, where there is a drop down menu for "available data for this site", and chose "daily statistics".  That brings me to a page where I checked the box for "Discharge, cubic feet per second", and went down the page to the drop down menu for "Table of ----- of daily mean value for each day, and chose "median".  That gives me a table of the median flow for each day of the year during the time that the gauge has been operating.  So now I can see what the "normal" flow is for each day of the year.  Doing a little eyeball averaging, I come out with this:

January--average normal flow is about 22 cfs.

February--47 cfs

March--63 cfs

April--110 cfs

May--100 cfs

June--44 cfs

July--12 cfs

August--12 cfs

September--5 cfs

October--7 cfs

November--10 cfs

December--20 cfs

So...now I know that the Little Niangua is NORMALLY too low to float without a LOT of work from July through January, marginally floatable normally in February and June, and usually floatable without much of problem in March through May.  That's on the upper end, so I gotta figure the lower portion might be a little easier to float in February, March, and June, but it still gets too low normally to be easy to float July through January.  That's entirely because of my rule of thumb...you need 75 cfs to float any stream of that general size without too much dragging and scraping.  

So...if you floated it on a certain date in the past, and remember the date and how easy it was to float at that time, if you gave me the date, I could go back to that date on the gauge site, find the cfs it was flowing that day, and tell you how easy it was to float.  Or if I am planning on finally floating it one day next June, and go the gauge and see what the cfs is, I can know beyond any real doubt how easy it will be to float that day.  All without ever looking at the height in feet, and on a stream that as far as I know, I've never laid eyes on before.

And by the way, I've floated a few streams at less than 10 cfs, if you could call it "floating".  The upper end of Big River comes to mind...I've gone down it quite a few times at less than 10 cfs.  It's walking the riffles and fishing the pools.  I've also floated streams like the upper Jacks Fork at 30 cfs...I might have floated 10% of the riffles without scraping rocks, 50% scraping bottom but not quite getting stopped and having to push with the paddle, and the rest getting stopped and having to push (which are the kind of places that really scar up your canoe bottom).  I bet the Little Niangua is pretty similar.

[fishinwrench]

53 minutes ago, Al Agnew said:

And by the way, you're wrong about 1.5 feet being enough water to float on every stream.

I never said that.  

I said....."I can tell you that any river with a guage height of 1.5 ft. is going to be low and barely floatable in spots.  "

[fishinwrench]

14 minutes ago, Al Agnew said:

First I looked to see where the gauge is located.  It's at the Hwy. 54 bridge.  Then I looked to see where the highest generally considered put-in is by Googling it.  Looks like the highest is only a couple miles above Hwy. 54.  But on the map, it doesn't show a whole bunch of creeks coming into the Little Niangua between there and LOZ.  And I know there aren't any really big springs.  So I figure whatever it's flowing at Hwy. 54, it probably won't be flowing any more than twice that much on the lower end before it runs into the lake.

Right.  But oddly enough if the guage reads less than 3' it's going to be skinny. It fishes and floats best at 4.5 - 5.

The big Niangua on the other hand is on the verge of being blown out at the same headwater guage height. And knowing CFS on the big Niangua above Bennett and the few other springs between Windyville and there is useless info.

Again, it's whatever you choose, I was just saying that for ME it works best to know guage height.   I'm never in the mood for excessive math.  I am rather fond of my old school "stick in the mud" technique. 😊

[Al Agnew]

8 hours ago, fishinwrench said:

Craziest thing I've ever heard you say. 😊 

I can tell you that any river with a guage height of 1.5 ft. is going to be low and barely floatable in spots.   There's no "minus" when measuring guage height.  Zero means DRY.  

When camping on the river I drive a steak in at the waterline or make a little rock pile.  Way easier to tell the degree of rise/drop by looking at that than it is to glance at the nearest riffle and guess the CFS flow compared to my memory of yesterday.

Here's another fun nerdy thing I just did...I went back in history on several streams that are like the Little Niangua, they get too low to float part of the year.  I tried to find a time when each was flowing that magic 75 cfs that makes it floatable without much problems, and equated that to the level in feet it was at that same time.  So you think that 1.5 feet is going to always be the same, low and barely floatable?  Here is what the level in feet for each of these streams is at 75 cfs:

Little Piney River--2.0

Upper Niangua, Windyville gauge--1.8

Little Niangua--4.4

Upper Meramec, Cook Station gauge--2.2

Big River, Desloge gauge--3.7

Upper Jacks Fork, Mountain View gauge--1.8

So yeah, 1.5 feet is going to be too low to float on all of these--in fact, on several of them the gauge doesn't even go that low.  But if you're wanting to know whether it's going to be easily floatable or not, you can see that for each stream the level in feet is different.  2.0 on the Little Piney equals 4.4 on the Little Niangua.  But 75 cfs is 75 cfs on every one of them, and that's the only figure I need to know when I'm trying to figure out how easy any of them will be to float.  You don't even have to do any math.  Just look at the flow in cfs on any of them and it will tell you whether it's easily floatable or not.

 

[fishinwrench]

Interesting but......Niangua is definitely floatable at 1.5 @Windyville, matter of fact that's a GREAT time to fish it.  But yes you will have to drag a riffle or two until you get below Bennett.

At 1' even, the upper Niangua is 89cfs (not less than 75, so I'm not sure how you calculated 1.8 @ 75cfs) and your DEFINITELY gonna be dragging the boat at 89cfs, you aren't gonna be floating that SOB at 75.  No freakin'way.

So what's the magic CFS number for running the jet jon on any river? Am I to assume that whatever CFS the Niangua@leadmine is at 4.5ft. would be fine for jet jon traffic?

Therefore 250-273 cfs ?    Thats good for all rivers then?  It is on the Niangua from Tunnel dam all the way up to the 64 bridge. 

But wait a minute, Windyville at 2.8' is 470cfs.(it's 2.89 and 574 right now).

Now my head is spinning.   Y'all go ahead with your CFS thing, I just can't handle it.  😟 

<calmly plugs ears and drives a stick in the mud>

[drew03cmc]

On 1/22/2020 at 8:07 PM, Al Agnew said:

Hey Wrench, just for fun I did a little checking on the Little Niangua, which happens to be one of the very few streams in the Ozarks I've never floated.  

First I looked to see where the gauge is located.  It's at the Hwy. 54 bridge.  Then I looked to see where the highest generally considered put-in is by Googling it.  Looks like the highest is only a couple miles above Hwy. 54.  But on the map, it doesn't show a whole bunch of creeks coming into the Little Niangua between there and LOZ.  And I know there aren't any really big springs.  So I figure whatever it's flowing at Hwy. 54, it probably won't be flowing any more than twice that much on the lower end before it runs into the lake.

Having established that, I then went to the USGS gauge for it (forget about the apps, they don't tell you nearly as much as the real gauge does, so figure out how to get the real gauge to load...I never have any problems with it).  What I did was go to the gauge site, where there is a drop down menu for "available data for this site", and chose "daily statistics".  That brings me to a page where I checked the box for "Discharge, cubic feet per second", and went down the page to the drop down menu for "Table of ----- of daily mean value for each day, and chose "median".  That gives me a table of the median flow for each day of the year during the time that the gauge has been operating.  So now I can see what the "normal" flow is for each day of the year.  Doing a little eyeball averaging, I come out with this:

January--average normal flow is about 22 cfs.

February--47 cfs

March--63 cfs

April--110 cfs

May--100 cfs

June--44 cfs

July--12 cfs

August--12 cfs

September--5 cfs

October--7 cfs

November--10 cfs

December--20 cfs

So...now I know that the Little Niangua is NORMALLY too low to float without a LOT of work from July through January, marginally floatable normally in February and June, and usually floatable without much of problem in March through May.  That's on the upper end, so I gotta figure the lower portion might be a little easier to float in February, March, and June, but it still gets too low normally to be easy to float July through January.  That's entirely because of my rule of thumb...you need 75 cfs to float any stream of that general size without too much dragging and scraping.  

So...if you floated it on a certain date in the past, and remember the date and how easy it was to float at that time, if you gave me the date, I could go back to that date on the gauge site, find the cfs it was flowing that day, and tell you how easy it was to float.  Or if I am planning on finally floating it one day next June, and go the gauge and see what the cfs is, I can know beyond any real doubt how easy it will be to float that day.  All without ever looking at the height in feet, and on a stream that as far as I know, I've never laid eyes on before.

And by the way, I've floated a few streams at less than 10 cfs, if you could call it "floating".  The upper end of Big River comes to mind...I've gone down it quite a few times at less than 10 cfs.  It's walking the riffles and fishing the pools.  I've also floated streams like the upper Jacks Fork at 30 cfs...I might have floated 10% of the riffles without scraping rocks, 50% scraping bottom but not quite getting stopped and having to push with the paddle, and the rest getting stopped and having to push (which are the kind of places that really scar up your canoe bottom).  I bet the Little Niangua is pretty similar.

June 9-10 2015 flow ranged from 40 cfs to 25 cfs and height from 4.77 to 4.60. Easy floating. Very good fishing on the Little Niangua. 

[fishinwrench]

5 hours ago, drew03cmc said:

June 9-10 2015 flow ranged from 40 cfs to 25 cfs and height from 4.77 to 4.60. Easy floating. Very good fishing on the Little Niangua. 

Yep, between 4 and 5' on the Mack's creek guage is perfect on the LN. 

The same level on the Niangua would be "blown out" (if going by level).

Or "dry" (if going by cfs).

It's 6ft at 240 currently.

I've been trying to make sense of Al's 75 CFS theory by going through my old journals (which I quit adding to 9 years ago), and while I'm sure he knows what he's talking about, my numbers don't jive on the entrys where I noted both the level and CFS at the time.    In fairness though yours on June 10 2015 don't either.     So I guess whichever you choose to follow and rely on.... you'd better stick with it, because relating the two together doesn't seem to work.

In my world of reasoning, going by CFS and saying that any river with that much water moving through it is going to be similar makes no sense, because the huge variable is always going to be how narrow/wide the stream is.    Going by the level and assuming that 1' is about the lowest it ever gets after a period of little or no rain.....that makes sense to me.  

[drew03cmc]

6 minutes ago, fishinwrench said:

Yep, between 4 and 5' on the Mack's creek guage is perfect on the LN. 

The same level on the Niangua would be "blown out" (if going by level).

Or "dry" (if going by cfs).

It's 6ft at 240 currently.

I've been trying to make sense of Al's 75 CFS theory by going through my old journals (which I quit adding to 9 years ago), and while I'm sure he knows what he's talking about, my numbers don't jive on the entrys where I noted both the level and CFS at the time.    In fairness though yours on June 10 2015 don't either.     So I guess whichever you choose to follow and rely on.... you'd better stick with it, because relating the two together doesn't seem to work.

I pulled the numbers off the USGS gauge site. That river fishes well when it is about 4.5 and the flow around 35 cfs or so.

[fishinwrench]

7 minutes ago, drew03cmc said:

I pulled the numbers off the USGS gauge site. That river fishes well when it is about 4.5 and the flow around 35 cfs or so.

That just doesn't compute for me.  4.5' is considerably more than 35cfs.  

It wouldn't add up using Al's method either.  

How could it possibly be 6' at 240, and 4.5 at 35 ?      Not even possible is it?