Dry Wells?

[Reverend Blair]

Anybody know anything about dry wells in heavy clay soil? I have a drainage problem out back and while the easy thing to do is just turn it into my neighbour's problem, I like my neighbour.

Where I grew up dry wells are a relatively common solution. It gives the water somewhere to go and keeps the ground above usable. It also gives you somewhere to dump all the rocks you pick off your fields.

Nobody around here has ever heard of them though, and I don't know why. I'm afraid that it has something to do with the heavy clay soil and I'm going to end up spending a bunch of money on what is essentially a hole in the ground.

 

[whistlepig]

Anybody know anything about dry wells in heavy clay soil? I have a drainage problem out back and while the easy thing to do is just turn it into my neighbour's problem, I like my neighbour.

Where I grew up dry wells are a relatively common solution. It gives the water somewhere to go and keeps the ground above usable. It also gives you somewhere to dump all the rocks you pick off your fields.

Nobody around here has ever heard of them though, and I don't know why. I'm afraid that it has something to do with the heavy clay soil and I'm going to end up spending a bunch of money on what is essentially a hole in the ground.

Correct me if I am wrong but I think you may be referring to a French well or French drain.

 

[Reverend Blair]

It might be different terminology due to place. In Saskatchewan we call them dry wells.

French drains are usually weeping tiles on the interior of a basement there.

Of course we also talk about eavestroughs (usually called gutters on US TV shows) and sloughs (most people outside of the Canadian prairies seem to call them ponds) etc.

In any case, what I'm talking about in this case is a hole full of rocks that gives excess water someplace to drain to in a yard or field. You dig a hole, put big rocks at the bottom and progressively smaller rocks all the way up, and cover it with topsoil.

Nobody seems to do that here in Manitoba, which seems ridiculous because there's a lot of standing water during wet years. I'm wondering if it could be due to the excessively heavy clay.

 

[whistlepig]

It might be different terminology due to place. In Saskatchewan we call them dry wells.

French drains are usually weeping tiles on the interior of a basement there.

Of course we also talk about eavestroughs (usually called gutters on US TV shows) and sloughs (most people outside of the Canadian prairies seem to call them ponds) etc.

In any case, what I'm talking about in this case is a hole full of rocks that gives excess water someplace to drain to in a yard or field. You dig a hole, put big rocks at the bottom and progressively smaller rocks all the way up, and cover it with topsoil.

Nobody seems to do that here in Manitoba, which seems ridiculous because there's a lot of standing water during wet years. I'm wondering if it could be due to the excessively heavy clay.

Yep. That's what we call a French well down here. I tried one once. A deep hole (4' dia. x 12' deep) filled with course stone and topped with dirt. It worked great until it filled up with water. I think a French well with drainage tiles attached leading away from it would work. Just digging a hole and filling it with gravel didn't work at all for me. It just postponed the inevitable.

 

[MikeD74T]

The term drywell is common in New England. That being a well (hole) into which one puts water rather than taking water from. Drywells don't work in clay for the same reason you need one, because the water won't absorb into the soil. About the only options in clay are to divert the water to somewhere else or create a diversion pond that will hold the water until it can evaporate. Often takes a really big area. For holes of equal volume shallower is better. MikeD74T

 

[tungularafishcamp]

Is it clay or do you have permafrost holding up the water?


Rick

 

[whistlepig]

The term drywell is common in New England. That being a well (hole) into which one puts water rather than taking water from. Drywells don't work in clay for the same reason you need one, because the water won't absorb into the soil. About the only options in clay are to divert the water to somewhere else or create a diversion pond that will hold the water until it can evaporate. Often takes a really big area. For holes of equal volume shallower is better. MikeD74T

That has been my experience with clay soils. Clay soils simply won't absorb the water. The water has to be tiled away. When we build ponds (sloughs) we line them with clay to prevent them from leaking water.

 

[Reverend Blair]

Darn, that's what I was afraid of, Whistlepig and Mike D74T. I've got no where to drain to either. I can fill the lowest spots with clean fill, which will help a bit, but if I go too far I'll flood out the neighbour and I definitely don't want to do that. He's a good neighbour and has some pretty nice cars in his garage back there.

Guess all I can really do is hope that we return to having regular dry years instead of this constant wet. Not much hope of that for next year though...we've already got far more snow than usual.

No, tungularafishcamp, there's no permafrost here. We're too far south to have to deal with that.

 

[CurlyDave]

No matter how much clay you have you do not have clay all the way to the center of the earth.

You need to get the bottom of the dry well below the clay layer and it will then drain water. Check with your county to see if they have any records of how deep the clay layer is. Someone will know this, you just have to find it.

Once you know how much clay to expect, you will be able to decide if it is worthwhile to dig a deep enough hole.

 

[Reverend Blair]

It goes down at least twenty feet, CurlyDave. I was in a major excavation downtown once, and they hadn't gotten below it. I would guess that it's far deeper than that too, given that the Red River flows on top of it. That puts it well beyond my capability to rent a backhoe to solve the problem.

 

[tungularafishcamp]

Is it pond building time?

Rick

 

[Gary Fowler]

Sounds like you need a retaining basin with drain that allows run off at a pre-determined rate that wont flood the neighbor but allows slow run off. YOU may be looking at a rather large basin if you have lots of water to contend with. It would be like a pond except the overflow line would be on the bottom of the dike rather than the top and it would need to be sized to allow the right amount of water to flow out so that it wouldnt flood the neighbor but still drain some of the water. You may even need more than one drain to release more water . If the level gets too high then an additional drain would kick in and release more

 

[Baby Grand]

Is it pond building time?

Rick

My thoughts, exactly. Although I think Gary has a better approach in mind. If the bottom drain allows you to retain some water (a la pond/slough) then you may have a very nice reservoir for the odd dry spell. Plus a good place for frogs and dragonflies.
-Jim
(Big fan of Sarah Harmer, formerly of Weeping Tile)

 

[The Dougster]

Curlydave is right. Somehow, you must get below the clay.. clay is impermeable and will not allow the water to drain away... might have to have a dry well drilled to below the clay layer, install a perforated pipe... just the reverse of a producing water well. Might have to check on permit requirements for an injection well....

 

[Reverend Blair]

I looked into the codes today. If I want a pond big enough to do any good, I have to enclose it in a 6 foot fence. Same rules as for a swimming pool.

I wonder if anybody would notice if I cut a trench through the empty field out to the highway?:laughing:

 

[JohninCT]

I wonder if anybody would notice if I cut a trench through the empty field out to the highway?:laughing:

Maybe not if you ended the trench at some distance away and let it flow through and disperse through a quantity of loose rock.

 

[Reverend Blair]

Hmmm...that just might work. The catch being that it's not actually my field.

 

[MikeD74T]

No matter how much clay you have you do not have clay all the way to the center of the earth.

You need to get the bottom of the dry well below the clay layer and it will then drain water. Check with your county to see if they have any records of how deep the clay layer is. Someone will know this, you just have to find it.

Once you know how much clay to expect, you will be able to decide if it is worthwhile to dig a deep enough hole.

I only have about 25' of clay on my property, however where it ends granite starts and granite does extend to the center of the earth. Granite don't drain well either. MikeD74t

 

[TripleR]

I have had the same experience as others and I am pretty sure where I live the clay does go all the way through the earth and somewhere a Chinese homeowner/farmer is complaining about the same problem.:laughing: