I Talked To A Native Of Yellville Today

[gotmuddy]

Did the flood gates opening change the White and North Fork much below the dams a few years ago. Would think it opened up some holes and really cleaned out the rivers.

It is weird how it works. The strawberry river starts near my house and every year when we get high water in the spring the holes change. Year before last we had a hole that was deeper than our heads, now its only waste deep.

[eric1978]

now its only waste deep.

I'd probably stay out of that hole then. That's nasty.

[gotmuddy]

I'd probably stay out of that hole then. That's nasty.

waist deep even

[Al Agnew]

About the holes in the White filling in when the flood gates were opened...correct me if I'm wrong, but even with the flood gates open, the river didn't really get out of its banks and up into the bottom fields, did it? I suspect that event was closer to what I called before "a little flood", that gets the stream up to about bank full. Little floods move gravel, but they don't pile it up into high gravel bars or blow it out into the bottom fields like a big flood does. Instead, they mostly move it into the pools and onto low gravel bars. So while a little flood like that could scour out some deep pockets around obstructions, they wouldn't be enough to scour out the big pools, instead filling them in.

The lower Buffalo has quite a bit of gravel in the channel, a lot of which has probably worked its way down from higher up in the river and farther away in the watershed. The lower river is surrounded by well-wooded land in all directions, with only creek, Big Creek, that drains substantial cleared land. Still, a real gully washer can dump a lot of gravel (and rocks) into the river...that's the reason Clabber Creek Shoal is where it is, because all those rocks and rocky bars there came out of Clabber Creek.

But one thing about the lower Buffalo...it has an exceptionally narrow, steep-sided valley with very little bottomland, just bluff on one side and hill on the other. That river can rise to unbelievable heights in major floods...measurements of 70 foot rises have been recorded at the Hwy. 14 bridge, and the valley narrows a little more yet downstream, so in some places those floods could have been even higher.

So the lower Buffalo is a classic river for having big floods that scour out pools and pile up gravel. Some of the gravel bars on the Buffalo are 20 feet or more higher than normal river level. And some of the pools are definitely impressively deep. In fact, what limits depth on the lower river is often that the river has been scoured down to bedrock.

I'm fascinated by the mechanisms of flooding, scouring, and deposition. Scouring occurs because of three things...the cross section differential in current speed that you see on a bend, the turbulence created by obstructions, and the narrowing and acceleration of the current in constricted areas. Deep pools are mostly seen in bends of the river because the fastest, most powerful current is on the outside of the bend scouring, while the slower current on the inside is perfect for deposition. So the gravel bar will be on the inside of the bend and the deep water on the outside. Deep pockets on gravelly streams are found around rocks and rootwads, where the turbulence blows out gravel. And narrow spots with stable banks will usually be deep just because the current cleans them out. But long, straight stretches will usually be shallow, and if those stretches don't have any obstructions and are wide bank to bank, they will be even shallower.

Another thing I've seen...sometimes the reason for a pool shallowing in isn't that it's getting filled with gravel. Riffles often act like little dams. If a flood event blows out a riffle, it can no longer pile up water above it when the river goes back to normal, and the water level of the pool above will be lower once the high water goes back down. There was a pool on upper Big River, long, deep, beautiful water. At the bottom of it was a big gravel bar and a riffle next to it, with willow trees lining the edge of the riffle. After one big flood, the next time I floated through there the pool seemed to be a good two feet shallower. Indeed, I could actually see a "bathtub ring" of dried moss on the rocks at the edge of the pool. I got down to the riffle and it was considerably deeper, with the roots of those willow trees exposed to about the same extent as the bathtub ring in the pool above. Instead of the riffle dropping off into the next pool, it just imperceptibly slowed down into it. That riffle had been a gravel dam keeping the pool above backed up, and blowing it out had lowered the level of the pool.

Just stop reading if I'm being boring, but another thing that's always interesting is what happens when a landowner clears the trees lining the river and the river begins to eat away the resulting mud bank. When you've been on the rivers as long as I have, you will know of places where this has been going on for a long time. What happens is that the section of bank, which might be on the outside of a bend to begin with, soon forms an outside bend even if it wasn't before, because that section gets eaten away in floods a lot more than the sections just upstream and downstream where the trees or a rocky bluff protect the bank. And once an outside bend starts, the faster current on the outside just makes the erosive force of the river more powerful and the bank gets eaten away faster.

So now you have an outside bend where the bank is very vulnerable, and an inside where gravel gets deposited. The river keeps eating at the mud bank on the outside, thus it's wanting widen the channel, but on the inside the gravel keeps getting piled up, and as the outside bank keeps moving farther away from the original channel, the inside keeps growing a wider and wider gravel bar. The river's width remains the same. After a few years, willows and young maples and sycamores start growing at the back edge of the gravel bar. They collect sand and silt in floods, being on the inside of the ever-growing bend and slowing the current further. After many years, you'll see a succession of plant growth. Starting at water's edge on the inside of the bend, as you walk directly away from the water you have clean gravel, then weeds and tiny saplings, then young willows and maples, then taller, older trees, and finally "full grown" maples and willows back where the original bank was, and that may be a LONG way from where the present gravel bar is. I've seen some of the outside bends be eaten back 100 yards or more in 20 or 30 years. Just above Mammoth Bridge on Big River, the high mud bank that you see on the left just above the bluff as you go upstream started out a good 100 yards away from that bluff back in the 1970s...the river used to come into the bluff at almost a 90 degree angle way back then. It has been eaten away now to where it's about to come up against the bluff, and then the erosion of that bank will finally stop.

[gotmuddy]

About the holes in the White filling in when the flood gates were opened...correct me if I'm wrong, but even with the flood gates open, the river didn't really get out of its banks and up into the bottom fields, did it? I suspect that event was closer to what I called before "a little flood", that gets the stream up to about bank full.

The flood was pretty bad.

[gotmuddy]

So the lower Buffalo is a classic river for having big floods that scour out pools and pile up gravel. Some of the gravel bars on the Buffalo are 20 feet or more higher than normal river level. And some of the pools are definitely impressively deep. In fact, what limits depth on the lower river is often that the river has been scoured down to bedrock.

The lower Buffalo is mostly bedrock. Thats what I like about it.

[snagged in outlet 3]

Thanks for the pics Gmuddy. Yeah Al, the flood waters went all the way into the campground on the Norfork which has to be a good 25 feet high up that bank. At Taney the pavillion was under water. The flood waters were in the golf course at The White.

I see what you mean though. In a specific area below Norfork there used to be a narrow chute that drooped into a good pool. Not the chute is wider and shallower and you can walk right across what was the pool.

I better get down there and do some research. Maybe this weekend.

SIO3

[Wayne SW/MO]

Crooked Creek is as close to a true riparian watershed as we have in the area and when we get regular rains you find the flows go from reasonable to insane in just a few hours.

More than the lower Buffalo??????

[gotmuddy]

More than the lower Buffalo??????

Once clear creek comes in CC halfway between pyatt and snow there are no more springs until just above the lower access. Thats probably 25 miles with nothing coming in. So after clear creek CC is the same as the lower buffalo.

That pic was the calico rock bridge. The river is usually 40+ foot below that bridge.

The water touched the bridge at allison.

[Wayne SW/MO]

Lost a post.:rolleyes:

I would have never thought the White could have reached the edges of Riley's Station, impossible. I've seen pictures where it was lapping at the edges of it. The river at normal must be 40 or 50 feet lower that the Station. I've often wondered how far it backed up the Buffalo there, which is across the river.