Entropy

Relax in southern comfort on the east bank of the Mississippi. You're just around the corner from Beale Street and Sun Records. Watch the ducks, throw back a few and tell us what's on your mind.
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JR.
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Re: Entropy

Post by JR. » Wed Dec 26, 2018 3:18 pm

Today's experiment is a small DIY silt trap at the high side of my trench (where drain goes).
DSCF0085.JPG
I made this from an empty one gallon apple cider jug. Two slots on the dirty side, one slot on the clean side. I obviously need a bigger bucket.
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Looked at the high side pipe where silt is coming in the side ditch, the bottom of that culvert/pipe has a couple inches of silt build up already...

I'll dig that silt well this weekend, after I get some plastic buckets.

Water still running down the trench slowly... not really sure where all the water is still coming from, uphill of me. Not that it matters, I can't fix my neighbors poorly cleared ditches.

JR

billshurv
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Re: Entropy

Post by billshurv » Wed Dec 26, 2018 7:51 pm

well that seems to be cleaning things quite a lot, so basic principle is good. Having more fun than me at them moment!

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JR.
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Re: Entropy

Post by JR. » Wed Dec 26, 2018 9:13 pm

billshurv wrote:
Wed Dec 26, 2018 7:51 pm
well that seems to be cleaning things quite a lot, so basic principle is good. Having more fun than me at them moment!
I meant to mention that the picture exaggerates the before/after... I stirred up mud trying to seal off the silt filter in place...

I did notice some silt deposit already on the bottom of the jug, so the concept is valid, but I need a bigger bucket...

JR

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JR.
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Re: Entropy

Post by JR. » Thu Dec 27, 2018 2:13 pm

Flash flood watch today so not much ditch work...

The buckets were bigger than I planned for, but I improvised.
DSCF0086.JPG
I set it at enough of an angle that the silt should go in, but like a roach motel, never leave again.
DSCF0087.JPG
You can't see it well with the light reflection, but I can already see clear water coming out on top of dark silt staying inside the bucket...

When we get the heavy rain forecast for today, I'll see where the bucket ends up. It may wash away if enough water flows.Over time I can get the bucket set better in the ditch, but it isn't in good yet.

[edit- no big surprise I just got back from rescuing my new bucket from my far back yard... it made it 70' down the mid ditch, made a left turn where the drain was, and another 50' toward the back ditch... I have some high water boots that were high enough. Despite getting flushed there was still mud in the bottom of the bucket so the concept is valid.

The front culvert pipe was roughly half full so 18"... the drain trench over a foot deep in places was full of water and still overflowing across the yard. So even 2 pipes will not carry this much flow, but that is ok, they don't have to. At least all the leaves are now gone. :lol: [/edit]
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50' more of new pipe showed up today so already enough pipe (150') for first course and about half of second...

today I had to dredge a couple hundred leaves out of my trench. The wind from the rain storm moving in, blew the leaves in from a neighbors tree (cottonwood,,, big ass leaves).

This is getting closer to finish but I may need to buy some better sized buckets for silt traps. I want to stabilize the silt flow in the ditch above the pipe, before buttoning up the new drain pipe.

JR

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JR.
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Re: Entropy

Post by JR. » Fri Dec 28, 2018 10:45 am

My ditch and open trench got a good test last night. My rain gauge only holds 5" and it was full but doesn't look like it overflowed. That is a big storm for here and lots of water still flowing in the ditches.

This was good fortune to gauge the trench dynamics with near worst case water load. Even with deep open trench peak water overflowed the trench and ran across the grass yard (the plan).

My DIY silt filters are still a work in process but my small one made from a one gallon apple cider jug did not get washed away and has about an inch of silt in it.

I have a bunch of 2 gallon plastic pails on order (<$2 each)

Weather report calls for more rain in the coming week so I won't button this up until after that... I expect my silt abatement to continue even longer, but I was constantly dredging silt out of my side ditch so this could end up being a long term labor saving. My fresh pipes won't clog up for another decade if I do nothing about silt.

Water flow direction seems to shift a little depending upon how much water is flowing. Yesterday at the height of the runoff water from the mid side ditch overflowed my almost 1' deep trench and flowed toward the back ditch/culvert. Recall I found my traveling DIY silt bucket 40-50' toward the back ditch. This morning with more moderate but still strong run off, water direction is from back to mid and ultimately front, the expected direction of flow (I know my back system does not drain low enough...due to poor municipal storm drain planning. My pipe and swale connecting my back storm ditch system to front reduced flooding and standing water in the neighborhoods east of my property ).

Today, several hours after rain stopped, still more than 4" flowing in my trench so double 4" pipes will earn their keep.

JR

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JR.
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Re: Entropy

Post by JR. » Fri Dec 28, 2018 7:47 pm

I'm having too much fun playing in the mud.... :lol:

Interesting new observation, I hadn't been running my crawl space sump pump, in case I needed the water later for ditch leveling (I've got too much water now so no need). Today I decided to route the sump output water into the 25' top section of old pipe... After flushing out much mud I started to hear an odd rattling sound... I ultimately flushed several pounds of gravel out of that old pipe... I now remember a strategy years ago where I dumped 50# or more gravel into the basin near the drain pipe inlet to stabilize the ditch bottom. In hind sight when the big water is flowing strong it can pick up and move gravel too. :lol:

I have another new idea... (no surprises). I think I will attach floats (like toilet bowl valve floats) to the intake end of my drain pipes. When the water flow is strong the water level will be higher so floats can lift the drain pipe inlet to up near the (cleaner?) top of the water stream. After the water slows down the pipe can drop down to get it all.

I am rethinking my thesis that slow water makes the most silt... logical that "more" water flow moves "more" silt. Lots of new silt in my side ditch from recent fast water.

I have a new 12" drain on order so I will use that for the bottom pipe, and my old 9" drain for the top pipe... Not perfect but 1 1/2" offset in the correct direction.

More rain coming this next week but getting closer to laying some new clean pipe. No hurry I feel a lot better about drain pipe version 2, without several previous mistakes.

I will use that 25' of (recently cleaned) old top pipe to make up the rest of the length I am lacking.

JR

billshurv
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Re: Entropy

Post by billshurv » Fri Dec 28, 2018 8:43 pm

Fast flow will pick up silt, slow will drop it. Which in theory means the best solution is to try and get the water to go through the pipe as fast as possible. The gravel that got in the pipe will not have helped as the silt will have collected round that, but anywhere the fall was reduced is likely to have clogged first.

Of course if you like digging holes you could put an inspection cover every 30' with a silt trap in it :D. Silly question but is there room for a pond at the top to catch the silt?

I'm still trying to get my head around quite how much rain you have there. Reminds me of the first time I visited Houston and saw the size of the drains at the side of the road and expected to see pennywise looking out at me!

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JR.
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Re: Entropy

Post by JR. » Fri Dec 28, 2018 9:59 pm

billshurv wrote:
Fri Dec 28, 2018 8:43 pm
Fast flow will pick up silt, slow will drop it. Which in theory means the best solution is to try and get the water to go through the pipe as fast as possible.
That is my current plan... 2 pipes will move the water out 2x as fast....

During ditch overflow the silt is harmlessly moving across the yard.
The gravel that got in the pipe will not have helped as the silt will have collected round that, but anywhere the fall was reduced is likely to have clogged first.
Top section with flattest grade had most sediment, gravel was mixed in with the sand filled pipe.
Of course if you like digging holes you could put an inspection cover every 30' with a silt trap in it :D.
I considered adding more spaced drains but pipe is too far below grade for a standard (12") drain box.
Silly question but is there room for a pond at the top to catch the silt?
There will be room for more than is there now... The classic trade off is that standing water provides a friendly habitat for breeding mosquitos. For years we have been dealing with "west nile virus" and the like (encephalitis variant spread by mosquitos). Over the last couple years the town spraying program appears pretty effective at keeping the mosquitos in check, but I am uncomfortable creating pools of standing water on purpose. I will expand the settling pond I added a few years back by the top drain, and add multiple DIY silt traps.
I'm still trying to get my head around quite how much rain you have there. Reminds me of the first time I visited Houston and saw the size of the drains at the side of the road and expected to see pennywise looking out at me!
Something over 50" a year... but it can be fun when you get 10% in a few hours. It has been wetter than normal this week. Those are once a year or once every other year storms. My brother lived in Houston for several years, they are flat and low ground (like me) so can't handle heavy rain runoff (like the recent hurricane there demonstrated).

An ideal solution does not exist for my property so I can only do what I can do... I am having fun inventing tricks like my inlet pipe floats. Another decade + seems easy, after learning what not to do.

JR

billshurv
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Re: Entropy

Post by billshurv » Sat Dec 29, 2018 12:02 pm

Usual trick in UK to stop mosquitoes is fish. I never got as far as putting them in the rain water tanks when I had them, but was tempted. there are various things you can put on the surface to stop them as well, but ours don't carry any nasties.

Almost goes back to the burying a barrel :)

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JR.
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Re: Entropy

Post by JR. » Sat Dec 29, 2018 1:14 pm

I see a bunch of tadpoles and crawfish in my front ditch, but not since that 5" downpour flush... :lol: (water still flowing a day later).

I have even seen snakes under water in my filled mid side rain ditch, no doubt eating craw fish and other tasty life forms.

In years past I have seen mosquito larvae and pupa swimming in my mid side rain ditch...in still water (my goal these days is to never have still water).

If I dig two silt ponds (one by culvert bringing silt in ) and one by my main drain(s), I can spray with something if water has not moved long enough to breed mosquitos. I may ask the town what they are spraying because it seems to work really well and they just drive by in the street with their pick-up truck misting an aerosol.

JR
[edit raining again but before that I trenched out my old silt pool, I need to make it bigger but almost immediately I saw lighter milky water aggregate in bottom of basin. BTW I did not find much (any?) of my 50# of gravel. :lol:
DSCF0088.JPG
Photo shows silt-mud accumulation from only a few days of DIY silt trapping. While silt flow may be a little heavier than usual, that is a lot of silt for such a short time.

I also raked up and burned the pile of leaves I dredged up out of my trench, because if I left them where they were, they would end up back down in the trench.

Weather report predicts sunlight next friday... :lol: [/edit

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