My careful ground re-contouring, done in advance of the heavy rains here in the south, has failed to keep up with the repeated deluges arriving here in East Texas, and indeed, across much of the south.
My “spider-sense” was also at work again: I’d had a sense (or gut feeling) that we would want to be ready to flee at a moments notice due to the predicted high rainfall levels.
No, it’s not just that the Septic System gets cranky during this kind of event. It’s that there is no septic system in the world that can effectively cope with all the rain that has fall hereabouts.
I flat out gave up on emptying the calibrated 6” rain gauge. So I know for sure and certain that we’ve had at least 12” of rain in the past three days, but more likely on the order of 14-16” inches of rain.
Just to put that into perspective, that’s twice of much rain in 3-days as Phoenix has had in the past YEAR.
The spider-sense on this was interesting. Part of me was inclined to dig out some drainage ditches around the property. The contouring of the land was done mainly 25-years ago. But, as you might expect, the effects of this much rain in this short of time, is to round everything off. In other words, gobs of rain is a kind of leveling device. The high spots wash out, the low spots fill in.
Note to kids under 40: If you live long enough, and close enough to the land in one place, you’ll develop an eye for this process at work. It’s also why new mountains are ragged – like the Rockies, and why older mountains have that softer, rounded-off look to them – like the Appalachians.
When the brother-in-law came back from town Wednesday evening, there was a lively discussion about how the last quarter mile of road where we live and where that “seasonal creek” that runs through our place is now a raging river. And it has undercut the 48” culvert which is running nearly full.
The odds of us being stranded here are very high. But that’s why we keep plenty of diesel on hand. And, as part of the spidey-stuff, I took the brush forks off the tractor so it will work fine with thick mud, which is what we may be filling in around the culvert with, later today.
We could go off on a tangent and talk about the really good part of super-rains, like this one. I figure instead of moving a yard, or two of dirt to get our road functional again, it might be more like 5-yards of dirt. And this is because of what civil engineers call “slump.”
Not something most people worry about, but it goes something like this: When a road crew puts in a culvert, they often do so in a manner that is prone to failure. In other words, working when the weather is drier, they will drop in a piece of culvert, pile up around it, and that’s that.
From the roadway, down to the bottom of the ditch around the culvert, may be at a faily acute angle. Picture a 45-degree hillside.
Now, if you really want the culvert to stay in place during a 100-year or 500-year rain event, what you REALLY would do (if you were planning to do the job RIGHT) would be to put in the culvert pipe about twice as long as you otherwise would.
Then, when you back-fill around it, put in much, much more dirt and gravel or whatever is handy. You want to do this so that the slope is more on the order of 20-degrees, and 10 would be even better.
When you get the 500-year rains, and the culvert begins to get seriously full, what happens?
Hydrostatic pressure builds. Since there’s not enough dirt on a 45-degree build, the water begins to work its way by, and around the culvert. Pretty quick, the water will hollow out around the culvert. And then the washing-out process gets going in earnest.
On the other hand, if the alternative water path is long, the culvert, which is really more like an earthen dam when you think about it (albeit with a spillway), the hydrostatic pressure is always lowest through the pipe other than around it.
Wikipedia has a great article on this whole slump concept (over here) but if you ever get around to doing major construction and there’s roadwork involved, look up the 500-year rain levels and set the slump off your roadbed down to the lowlands around it, at a very conservative angle. I can tell you that if you set it to a dry earth slump, you’re just building a temporary roadway.
And that’s what people from Texas to the East Coast are finding out as some record rains continue to fall in the region.
Oh, also go look at the concrete slump test backgrounder on Wikipedia, as well, because that will give you a very good way to judge the moisture content of concrete next time you’re doing a pour. To a surprising degree (surprising in that most people don’t know it) when you are mixing a batch of concrete, generally the strength of the concrete is higher with a drier mix.
As you can see from my penciled in lines, super wet dirt wants to naturally collapse. And while I am no expert on civil engineering and road-building, you can see how the slump angle becomes critical. It becomes less acute as the water is added. When the ground gets to be saturated, the mud will flow and the angle at absolute saturation will flow to level with any kind of agitation. Which is why leveling floors is usually done with either screed boards down on your hands and knees, or you rent a finisher (power rotary troweling works to level things), or you get a concrete vibrator which yes, ladies, runs on something bigger than double A batteries.
As long as we’re on concrete, next time you do a pour for something like a patio, make sure you pay the upcharge and buy 3,000 or better 3,500 or 4,000 concrete and slump it when delivered. Make sure that you don’t get watered down 2,000 pound concrete because while it might work for a while, it is very likely to crack and be ugly, and not hold together for a few hundred centuries like dry slumped, 4,000 pound concrete would, if you’re generous on the rebar and such.
Tomorrow, I will get a few pictures of all this crap going on here and you can get your junior soils engineer in training certificate.
That’s because this is not one of those every-day prepping topics, but when you think about it, how many prepping sites will keep 20-foot sections of culvert laying around waiting for 500-year rains and a couple of barrels of preserved diesel and a well-oiled tractor so you can go easy on your back?
One other thing this does? Builds huge admiration for the Chinese because these are the kind of problems they had when they built the “Great Wall” – all 13,000 miles of it, or so.
In the meantime, we called our casinos over in Shreveport (might as well have some fun while the run-off runs off, so to speak. They are open, but the problem is getting there. Parts of Instate 20 are closed – which turns getting there into an impossible problem.
This means this will be an ideal time to wave good-bye to the ranch for a couple of days and head out for more statistical research at the tables. I’d rather gamble on 17 on a roulette wheel than one what happens when I flush.
Me? The spidey-sense still was/is worried about the large earthen dams upstream on the Red River because when I was out tractoring last week, the ground here was still close to saturation and that was before the mass rainfall event…
And looking ahead – the macro picture?
This is very bad news, and I’ll explain why:
Let’s imagine for a moment that there was a major increase in worldwide ocean evaporative rates during the exceptionally high solar cycles peak from 1998 to 2003.
That would (at least to the simple George) drive a lot more water into the atmosphere.
Now, spin up to the present times. We have had an unusually warm winter and that means that the air over the US can hold a LOT more moisture.
As the cold comes through, the moisture wrings out and down comes the rain. This cold wrings out moisture is also while you have to pee more often when you get cold while fishing…kidneys are cold-sensitive, too. (If you’ve never gone early-morning fishing on a cold day after drinking two cups to wake up…)
In the yellow highlighted area is the end of this mess, but that looks like it won’t be over until a day, or three, from now, depending on how far east you are. And that gets us to the advisory area between those two lines our shaky-handed staff artist (me) drew in…
If you have to go flying today, that ugly patch which covers part of New Mexico, Texas, Colorado, Kansas, and the like is warning of moderate to severe turbulence.
Repeat after me the old pilot saying:
It’s better to be on the ground wishing you were UP THERE
than to be up in the air wishing you were DOWN HERE.;
It’s one of those days in that area which is why I am a long-living flat-out cowardly private pilot and haven’t gone for my commercial or ATP. So you might as well stay home and work on your junior road engineer badge.
Besides, I might hit a big winner…in which case, 1099 me please! Which are the two most important words to “send upstairs” for Noah if we can get there. Otherwise something more practical is in order. Like…
Yes Sir, Mam, or Other Dept.: Customer Service
T’other day, someone said in the comments section, that they would like to have a way to forward a link to a column to a friend now and then. Probably on days when our odd sense of humor is really on the fritz and the meds aren’t working.
So at the top of this page, right-hand column, you will see a shiny new option. Called send link to a friend, we don’t harvest emails, or anything. I just thought it was a damn fine idea.
So if you find a column that is really exceptionally good, now you can send it to a friend easily.
For the other 99% of columns? Send them to enemies.
Well, now: With the blood pressure at 120/71, this doesn’t shape up as too stressful a day – so far…
Write when you break-even,