How do I read a river's water flow chart

I’m planning to take the kayaks out to the Brazos river just below Possum Kingdom lake. I was told to “check the river’s flow rate” and a quick Google search took me to the Brazos River Authority website. There I found an “Interactive Map” which made very little sense to me. I then found a link to and was further confused.

Is there a simple way to figure out if the dang river is going to have any water in it?

Call someone nearby
It’s merely a tool, best info is scouting it personally

so confused
What I mean is I see this chart:

09/06/2012 00:00 CDT 65.97P 186P

09/06/2012 00:15 CDT 65.98P 189P

09/06/2012 00:30 CDT 65.97P 186P

09/06/2012 00:45 CDT 65.97P 186P

09/06/2012 01:00 CDT 65.97P 186P

The last column’s title says it is:


This website says the optimal flow is 500cfs-3000cfs.

So, is 186 the cfs? And, if so, how do you see what the flow is “going to be”…all this looks like it is in the past.

Inside is a link to a trip report that
started where you want to. There are people on Old Sparkey’s Forum who run the Brazos all-the-time.

I’m trying to get to the relevant USGS gauge, but the Brazos has a million gauges and I don’t know which is for below Possums Kingdom.

In spite of recent rains that took the edge off the drought, I doubt that you’re going to have good water in September.

The location maps on the USGS aren’t
working for Texas. My guess is that the Grafford gauge is close enough. It shows a jump in water flow to a little under 200 cfs. That would be plenty on a low gradient Louisiana swamp river, but not enough for comfort on a gravel bar river like the Brazos. I’d guess 300 cfs might be enough to get by.,00060

The gauges…
don’t predict the flow, they just tell you what the flow is as of now. For what it’s worth, in the gravel bar rivers of the Ozarks, 200 cfs would be plenty of water to float. Unless the Brazos is a considerably wider river than those in the Ozarks, I’d think you’d be able to float it at anything over about 100 cfs, though 200 or more cfs would be better.

A matter of taste. I don’t know of any

– Last Updated: Sep-08-12 12:01 AM EST –

rivers with gradient-created gravel bars where 200 cfs will be "plenty." I will go back and check flow for dates for when we ran the middle Buffalo.

OK, we were running tandem in April, just us and no gear, and we had a bit over 500 cfs on both days. If you ask me if I would have run those gravel bars with just 200 cfs, I say NO, but maybe you would. Even 500 wasn't what I would call "plenty." Adequate, yes.

I also ran the Eleven Point in a dry August when the main source of water was Greer Spring. I think it contributes about 260 cfs. The water level I would describe, not as "plenty," but "just enough" to get down the river and see the scenery.

Low gradient piedmont rivers in GA and can sometimes be run at 250 cfs, but lower than that and you'll stick on the shallow ledges.

Been Running the Current All Summer…

– Last Updated: Sep-08-12 5:54 AM EST – 150-160 cfs. Plenty, just enough, it's enough to float loaded boats. I'd rather have more, but it's doable and you take what mother nature gives you! Thankfully we've received rain the last two days so no 160 cfs NEXT week!!

To answer the more general question
The gauge will tell you how much water is in the river – in terms of CFS or feet or both – at a given time, but the gauge can’t tell you whether that level is boatable or what the level will be tomorrow.

To find out what levels are boatable, you have to have some other source of experience that informs you. Guidebooks are one such source. They will say the river is high, medium, low, or barely get-down-able at thus and so level ranges.

Other sources of how gauge levels correspond to boatabilty are other paddlers who know the river, trip reports on the web, outfitter websites, or your own personal experience. Go out yourself and look at a river when the gauge reading is X, Y and Z. Then you can make your own judgment as to how boatable the X, Y and Z levels are.

Before the computer age, we had to know someone near the river or personally drive to the river to scout its level. I spent many a day driving hundreds of miles to scout river levels all over the northeast for trips I was running. On dam controlled rivers, we had phone numbers of dam keepers to find out release times and levels.

How do you know what the level will be tomorrow or next weekend? In the old days you would just learn by experience how well and how long a river “held water”. Today, you can study past graph trends from the gauges to make these predictions.

It’s all part of the sport.

Hope this helps…
What I do is go to the state-wide Daily Streamflow Conditions map at the USGS site. In the upper right corner is a box labeled “Pre-defined displays.” From the pull-down menu select “Daily Stage and Streamflows”. Then click the on the dot on the map representing the station closest to where you want to paddle.

You’ll get a page with graphs of both the flow rate (in cubic feet per second, or ft3/s)and the gage height in feet above a theoretical datum point for the date. The flow rate graph will have triangles representing average flows for the date. The gage height graph will usually roughly parallel that flow rate graph, but gage height graphs will smooth out, for example, as one gets farther from a dam or if there is a wide marsh or flood plain.

All you then need to know is whether the river in question is normally, on average, navigable on that date. Your River Authority could probably answer that for you. And you’ll know how much above or below average it now is.

Hope that helps…

It is a matter of…
what you want out of the float. 100 cfs is generally enough to float a loaded boat through most of the riffles, and that’s all I meant by saying it’s enough, and 200 cfs is plenty. That doesn’t mean it’ll be fun for you if you’re looking for fast water or if you want to run everything without having to worry about picking the right line.

I’ve run the lower end of the Buffalo at 70 cfs, in a heavily loaded solo canoe. I scraped bottom in most of the wide, gravelly riffles, and had to walk Clabber Creek Shoal because there just wasn’t a clear line between the rocks, but other than that I seldom had to get out and walk. The interesting thing is that we did the float from Gilbert to the White River in five days, and the floating was actually better between Gilbert and Buffalo Point than it was below Buffalo Point. There just isn’t much water coming into the river below Gilbert in low water conditions, so the flow above Buffalo Point is pretty much the same as the flow below, but the riffles are narrower, and thus a little deeper, above Buffalo Point than below it.

So…while you can run just about any Ozark stream at 100 cfs, if it’s a wide river like the lower Buffalo, you’ll have more trouble running it at 100 cfs than you will a narrow stream like the Jacks Fork.

ran the Brazos
We ended up going to run the Brazos on Saturday-Sunday. The flow was fine and we only had to get out a couple of times and walk maybe 25 feet before we could start paddling again. The trip from Possum Kingdom to Hwy 4 is 20 miles. The good people at Rochelle’s Canoe Rental shuttled us up ( in my truck ) for $30 and then locked my keys in it at the bottom so it was waiting for me when we were done. Seemed like a reasonable price. We paddled 13 miles the first day and 7 miles the second day. It took us about 10 hours total of paddling but mostly because we were taking our time, fishing, screwing around, etc. All and all it was an awesome trip and can’t wait to go back.

Good To Hear!
Sounds like you had a good trip. Reasonable shuttle price, for sure. I actually had an outfitter I’ve recommended and used myself for decades hang up on me when I tried to ask him if he would give me a break from the $40 he normally charges. And that was for a 6-7 mile paddle.


Glad to hear all went well
Now’s a good time to check those river levels and maybe start a notebook. You now know exactly what to expect on that section of that river at whatever the flow and gage height was reading on the day you went.

Our local livery charges $2 per river mile for shuttle. That strikes me as maybe reasonable for a short weekend trip, but I have 97 miles of uninterrupted river I could do. I can almost drive the 600 mi to the Ozarks and back for about the cost of being shuttled solo for the length of my home river. That’s not such a good deal, IMHO.

Better to work out a plan and do a trip with fellow paddlers if you can. Do your own shuttles. Or, if that can’t be worked out for some reason, hire a group shuttle and split the fee. It’ll save some bucks. Paddling should be a cheap sport once you’re equipped.

Exactly! I keep notes on levels, etc in a river guide I have.