Long term which drains better soil or gravel?

Please notice I said long term - like a few years down the road. A contractor dug some trenches for me to drop some new underground wiring into for some grain bins a couple days ago. When he was about done it came to my attention that I was having increasing problems with waterlogged pits under the horizontal unloading augers. The pits are not that big - just an earthen hole about the size of a bushel basket to get the loading auger in. While he was there I decided to have him dig a trench out in front of the holes to drop a 4" tile into to see if I could keep them dry. Outlet was near by. Contractor said to back fill under the discharge augers with washed 1" limestone gravel. Now initially I could see the water getting to the tile faster while the gravel is clean. But, of all places under a bin discharge aren't all of the voids in the gravel just going to get filled in eventually????? Once the voids get filled in could the water actually move slower into the tile???? Water isn't going to move through a piece of rock. Just trying to figure out whether to go get some rock or just use the native soil. Any ideas or experiences in regards to water movement through clean 1" limestone rock over the long term?? Thanks

All the rock filled drains they are putting the developments around me are done with a kind of fabric to minimize the rock getting silted up. They dig the trench. Line it with drain fabric. Backfill partway with rock. Install the perforated pipe. More rock. then lap the fabric edges over the rock and finish filling with dirt.

French drains work for decades and they are just gravel filled trenches. Remember that the crap is not going to fill the voids all the way down to the pipe. Just the surface will get much foreign matter. Soil will not flow water as well as the gravel.

I put a French drain in around my grain bin and a new shed I put up a few year ago, the new shed was back set about 10 feet to the front of the grain bin and I ran it between the two. I had a problem with water wanting to stand around my bin with heavy rains. however I did dig mine with a 72 inch skid steer bucket so that was the width and ran the taper down to the edge of a hill. I end up with about 18 inches of drop on 30 feet. and filled and leveled off with number 2 stone. now in a heavy rain with in a hour or so all the water gone, works great.

We put in under drains all the time. We wrap the rock and pipe in fabric. You can get pipe that is already wrapped with a fabric sock and foam peanuts. Old timers used to put spread newspaper on top of the rock to keep the dirt out.

You need some sort of drain with filter fabric to protect the washed stone. Voids will fill up under those conditions for sure.

Gravel is always going to drain better than soil, especially clay soils. Even if it silts in the movement of the earth insures it will drain better.

Well.....

There is soil.

And gravel.

And rock

Gravel would work well. Around here anyhow gravel is sand through 1 inch rock, or so, all mixed together.

Rock will work better, but you would want a filter, and perhaps a couple inches of finer material on top of that. Otherwise with just 1/2 inch rock to the surface, I understand your concern.

Paul

I replaced an old leeching bed. When I dug it up the rock was completely packed with dirt between the rock. No wonder it wasn't working rite. I cover the leeching bed rock with old asfalt shingles. Gets rid of the old shingles and keeps the dirt out of the rock.

The standard is red rosin paper over the laterals not "asfalt" shingles. Obviously no inspector was involved.

Those shingles will be there long after that paper is gone!

I've had as good a result with hay over the gravel than anything else. An old guy told me that by the time the hay rots (2 or 3 years), the soil above it will have stabilized and won't leach into the gravel through the composted hay.

Filter fabric is mighty cheap insurance.

Filter fabric is mighty cheap insurance.

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That would be my thoughts. I'm sure that soil type plays a big role in whether or not your rock will get silted in. If you have a chance to see what others are doing nearby on [u:e8318f0fa3]engineered[/u:e8318f0fa3] drainage work you will have a better idea of what needs to be done to work best.