Wednesday, August 28, 2019

Understanding and Using River Gauges, Part 3

In many ways, the rivers of the Ozarks are all similar.  They have much the same characteristics, so much of what holds true for one stream is true for all of them.  That makes using the river gauges even more useful, because there are universal "rules of thumb" that you can rely upon in attempting to figure out the water conditions on a given stream.

The first thing you need to remember is that the "normal" flow for any of these streams is considerably higher at certain times of the year than at other times.  Typically, from late winter through late spring, these rivers are at their highest "normal" flows.  By June those normal flows are dropping, until August through October the streams are at their lowest normal flows.  So a flow that might seem quite high in August will be close to normal in April.  To get the most out of the river gauges, it helps to know what the normal flow is in April and in August.  In the case of the Jacks Fork near Mountain View gauge I referenced in Part 2, I went back to the beginning and end dates, and changed them to a week in mid-April of this year, to see what the median flows were during that time period:
Look at the little triangles that denote the median flow, not the blue line that shows what the river was actually doing that week.  They show a "normal" flow between about 140 cfs and 200 cfs.  Let's call it an average of 180 cfs.  So that's about what the normal flow for the upper Jacks Fork is in the spring.  Remember in Part 2, we saw that the Jacks Fork was flowing 184 cfs on the day in August when we were investigating it.  While that seemed high for August, we now know that in the spring it would be considered a normal flow.  What that tells me is that while the river is higher than normal, it wouldn't be so high that it was up in the willow bushes.  Indeed, that's almost the last piece of the puzzle we need to know to determine the floatability of the upper Jacks Fork on the given date.

The last piece of information is one you can't get from the gauges.  I call it "Al's rule of thumb on river flows".  Since the rivers of the Ozarks are similar, a given flow in cfs that is high enough to make one stream floatable is enough water to make any stream in the Ozarks that is reasonably close to that stream in size floatable.  By looking at the flow in cfs and following my rule of thumb, you can determine immediately whether a stream has adequate water for paddling--or jet boating, for that matter.  Here it is:

Streams with median flow less than 300 cfs:

Flow less than 50 cfs--not easily floatable; a canoe or kayak loaded with a day's gear will scrape bottom in most riffles and a good portion of the riffles will have to be walked, dragging the boat.

Flow 50-75 cfs--still not easily floatable; some narrower riffles without obstacles will be runnable without scraping bottom, and if you don't care much about your boat bottom you will be able to paddle most riffles.

Flow 75-100 cfs--floatable; canoe or kayak will still scrape bottom on some of the wider riffles and split channels around islands, but the majority of riffles will be runnable without touching bottom if the right lines are chosen.

Flow 100-150 cfs--quite floatable; if the right lines are chosen, a canoe or kayak will only scrape bottom in the widest riffles and some split channels.

Flow 150-350 cfs--optimal floating level; the river will be moving well, the riffles all deep enough to run without scraping.

Flow 350-600 cfs--floatable but high; riffles all runnable, but obstacles such as sweeper and strainer trees become more difficult to avoid and the consequences of mistakes are worse.  At this flow, streams that are ordinarily too small for jetboats may become navigable by jetboats if there aren't too many obstacles.

Flow 600-1000 cfs--upper limits of navigability for most paddlers;  only get on the stream if you are very confident in your paddling abilities in heavy, fast water with obstacles.  Anything over this is probably too high and dangerous.

For streams with median flow over 300 cfs:

Flow less than 100 cfs--real drought conditions with dead low water, these ordinarily floatable and jetboatable streams will be low enough that jetboats are out and paddlers will scrape bottom in many riffles.

Flow 100-200 cfs--floatable with few problems, but jet boating may require considerable experience and somewhat of a disregard for your motor, because it will be sucking up gravel.

Flow 200-400 cfs--easily floatable, experienced jet boaters should encounter few problems except for obstacles like downed trees, but riffles with larger rocks may be dangerous and difficult to run.

Flow 400-800 cfs--floatable and usually fairly easy jetboating.

Flow 800-1500 cfs--floatable but heavy, fast water; usually very easy to float but the consequences of mistakes begin to be dangerous.  jetboating optimal.

Flow 1500-2500 cfs--at the limits of floatability; you'd better be good and prudent.  Jetboating becomes easy but mistakes could be very costly.

Flow over 2500 cfs--stay off it. The only possible exceptions to this rule are the very largest Ozark streams like lower Current and Gasconade rivers.

Not all Ozark float stream stretches are covered well by gauges.  Our Jacks Fork example is one of the few streams that are very well covered.  The Mountain View gauge, at Buck Hollow, is an excellent indicator for the river above Alley Spring.  Then there is the Alley Spring gauge, which actually is located at the bridge above Alley Spring, so it is most useful for the stretch above Alley--it's pretty exact for Bay Creek to Alley; and the Eminence gauge, which is perfect for Alley Spring to the mouth of the Jacks Fork.  But on many streams, you must understand that tributaries (or large springs) coming into the river downstream of the gauge location can render the gauge useless for the river below them.  Current River, for instance, has a gauge at the headwaters at Montauk, one above Akers, at Van Buren, and at Doniphan.  You would think the Van Buren gauge would serve well for the river down to Doniphan, but Big Spring comes in not far below Van Buren and adds an average of something like another 350 cfs.  So actually the Doniphan gauge is better for the river below Big Spring.  Since the Jacks Fork comes in well below the Akers gauge but well above the Van Buren gauge, the Akers gauge is most useful for the river between Akers and Two Rivers, the Van Buren gauge is better for the river between Two Rivers and Big Spring.

And then there are the rivers that are not served well at all by gauges.  The Gasconade in a 250 plus mile long river with two major tributaries and many smaller but significant streams feeding it, yet it only has three gauges; at Hazelgreen, at Jerome, and at Rich Fountain.  The Jerome gauge is good for much of the river downstream, and the Rich Fountain gauge gets more useful the farther downstream you go.  But Jerome is only useful upstream to the mouth of the Big Piney, just 8 or so miles above.  The Hazelgreen gauge is below the mouth of the Osage Fork, and good from the Osage Fork to the Big Piney.  But there is no gauge at all that will tell you anything about the 75 miles of floatable water above the Osage Fork.  And there isn't a gauge at all on the Osage Fork, either, and the only two Big Piney gauges are both on the lower section of the river, and aren't too accurate when considering the upper half of the floatable length of the Piney.

So if you regularly float a stream that isn't well covered by gauges, you can still make some assumptions by looking at the gauge closest to where you want to float, but they won't be perfect.  If you're floating an upper portion of a stream and the only gauge is far downstream, if that gauge is close to normal you can make a good guess that the upper river will be close to normal as well.  But what if it rained hard on the upper watershed and the upper river had a big rise that just hasn't gotten down to the gauge on the lower river?  In other words, reading gauges is often not an exact science, and you must use other sources of information.  In the case above, a weather report from somewhere in the upper watershed might tell you that there was that big rain that probably affected the upper river.

Another bit of useful info that you can't get directly from the gauges--if there has been rain in the area in the last few days, you can assume that the river may have had a significant rise.  But what constitutes "significant"?  Al's rule of thumb on rises is that if the rise is less than 6 inches and the river was near normal before the rise, the river may have gotten a little murkier than it was but probably not muddy, and fishing should still be okay.  If the rise was around a foot, there's a better chance the river got a slug of muddy water, and it might take a couple days for it to get back to normal clarity, but the chances are still fairly good that it will only be murky and fishable.  If the rise is between a foot and two feet, there's a real good chance the river got muddy, and fishing prospects aren't good.  If it's more than two feet, forget it.

If you read the gauges as I have outlined, paying close attention to the flow in cfs and using the height in feet only for determining how significant a rise was, and you remember the rules of thumb on floatability, you should be able to have a good idea of river conditions on most of the rivers of the Ozarks.

Following is a listing of gauges in the Missouri Ozarks and the stream sections for which each is most useful. An (*) in front of the gauge means the median flow of that gauge is under 300 cfs.  See above for the differences between streams with median flows under and over 300 cfs when considering "Al's rules of thumb for river flows".

Meramec River

*At Cook Station--upper river above Maramec Spring only.
Near Steelville--Maramec Spring to Onondaga.
Near Sullivan--Onondaga to Moselle Access at the mouth of the Bourbeuse.
At Pacific--mouth of Bourbeuse to Hwy. 66 State Park.
Near Eureka--below Hwy. 66 State Park.

Big River

*At Irondale--Irondale to Leadwood Access.
*Below Desloge--Leadwood Access to St. Francois State Park.
*Below Bonne Terre--St. Francois State Park to Washington State Park.
Near Richwoods--Washington State Park to Brown's Ford Access.
At Byrnesville--Brown's Ford to the Meramec.

Bourbeuse River

*Near High Gate--upper river to Noser Mill (Hwy. 185).  Note that this gauge is very far upstream and isn't really very accurate over most of the floatable portions of the upper river.
*At Union--Noser Mill to the Meramec.  This gauge is most accurate for the stretch beginning at the mouth of Spring Creek, which is about 8 miles below Noser Mill.

Huzzah Creek

*Near Steelville--only gauge on either Huzzah or Courtois, and most accurate from Highway 8 on down on the Huzzah.  It can be used to make a decent guess as to conditions on Courtois Creek, since it is very close to the Huzzah and is about the same size, so usually has much the same water conditions.

Gasconade River

Near Hazelgreen--accurate from the mouth of the Osage Fork, a few miles above the Interstate 44 bridge and Hazelgreen Access, to the mouth of the Big Piney, though keep in mind that enough springs and tributaries come into the river in that stretch that it will be flowing significantly more water by the time you reach the Piney.  It is of marginal use for the 75 miles of river above the Osage Fork, and there are no gauges covering that long reach.
At Jerome--mouth of the Big Piney to about Paydown Access.
Near Rich Fountain--Paydown to the Missouri River.

Big Piney River

Near Big Piney--accurate from about Mason Bridge Access to Fort Leonard Wood.  No gauges serve the river upstream from that stretch.
Below Fort Leonard Wood--Fort Wood to the Gasconade.

Little Piney River

*At Newburg--fairly accurate for the floatable portion of the stream.

Niangua River

*At Windyville--use this gauge for the Niangua above Bennett Spring.
Above Lake Niangua near Macks Creek--Bennett Spring to Lake Niangua.
At Tunnel Dam near Macks Creek--Tunnel Dam (Lake Niangua) to Lake of the Ozarks.

James River

*Near Springfield--above Lake Springfield.
*Near Boaz--Lake Springfield to the mouth of Finley Creek.
At Galena--Finley Creek to Table Rock Lake.

Bryant Creek

*Near Tecumseh--most accurate for the lower portion of the stream, only gauge on Bryant.

North Fork

Near Tecumseh--good for the stretch from Rainbow and Double Springs to Norfork Lake, of marginal usefulness upstream from there.  Only gauge on the North Fork.

Eleven Point River

Near Bardley--Greer Spring to the Missouri state line.  Of marginal usefulness above Greer.  Only gauge on the Missouri portion of the river.

Current River

*At Montauk--Tan Vat to Akers.
Above Akers--Akers to Two Rivers.
Above Powdermill--this is a new gauge and so far is not showing the flow in cfs.  Right now it is of marginal usefulness, but eventually it will be useful for the river between Two Rivers and Van Buren.
At Van Buren--Two Rivers to Big Spring.  It is less accurate than the Powdermill gauge will be above Logyard.
At Doniphan--Big Spring to the state line.

Jacks Fork

*Near Mountain View--Prongs to Bay Creek.
*At Alley Spring--Bay Creek to Alley.
At Eminence--Alley to Current River.

Black River

Near Annapolis--Lesterville (mouth of Middle Fork) to Clearwater Lake.
Below Annapolis--oddly enough, this gauge is only a couple miles below the one above; the only difference is that it is within the flood control pool reach of the upper river.  It often registers significantly different from the Near Annapolis gauge, but there is little reason for it.  I prefer using the Near Annapolis gauge for the upper river.  Note that many floats start on the West Fork above the mouth of the Middle Fork, and neither of these gauges is particularly accurate for that stretch.
At Leeper--Clearwater Dam to Leeper.
Above Williamsville--Leeper to Hwy. 67.
At Poplar Bluff--Hwy. 67 to Poplar Bluff.

St. Francis River

*Near Mill Creek--most accurate from the mouth of the Little St. Francis to the mouth of Marble Creek, not a very long stretch.  This gauge is used for the whitewater sections of the river at Silvermines and above, but those stretches are above the mouth of the Little St. Francis and it often adds considerable water to the river.  You can get a slightly better idea of the river through the whitewater sections by checking this gauge and the Little St. Francis gauge, and subtracting the flow of the Little St. Francis from this gauge, but there is no good gauge reading for the whitewater stretches.
*Near Saco--mouth of Marble Creek to Sam A. Baker State Park.
Near Patterson--Sam A. Baker Park to Wappapello Lake.

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