Rain and groundwater drainage piping and what to do with the water

[medic0648]

Have you looked on craigslist for the tanks? Also see new septic tanks for pretty cheap at times in my area(ne tx.) If you talk to a geologist in the area they'll probably be able to tell you if and how deep a permiable layer is to try and drain the water. A couple of 12-18in pipes about 10ft deep shouldn't be too hard to sink if you had to go that deep to sand.

 

[dave1949]

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But since water will find its own level, maybe you can find a way to use that. Perhaps a dry well part way down the slope, with the input lower than the output "overflow", which then slopes to daylight at your retaining wall? You'd have standing water in the input pipe to the level of the output pipe until the soil dried out enough to where the drywell itself would drain into the soil again, but it might be good enough to get you past the worst of it.

Just a thought...

I think that would work pretty well without needing a pump, except for heavy spring rains that occur when everything is still frozen. I don't think that would happen often, but it is a possibility.

 

[PAGUY]

What about a pond or water runoff pit like you see at housing developments at the lowest part of your property? If you dug down below the clay layer you would get absorption and evaporation to solve your problem.

 

[jim_wilson]

I think that would work pretty well without needing a pump, except for heavy spring rains that occur when everything is still frozen. I don't think that would happen often, but it is a possibility.

That's the exact type of situation I had been attempting to design around. That's when the water problems are the worst.

 

[dave1949]

That's the exact type of situation I had been attempting to design around. That's when the water problems are the worst.

You might be able to over come the freezing. If the inlet pipe is below the frost depth and the sump pit is insulated, which you can help tremendously by covering the line and pit with Styrofoam, it should not freeze up. The outlet pipe should only receive water when the sump pit fills, so it might not freeze as running water and it could be insulated also.

 

[dave1949]

Slabs for Colder Climates, Part 3: Installing Frost-Protected Shallow Foundations for Unheated Buildings - Buildipedia

If you use the techniques shown above, or Google "shallow frost protected foundations" for more info, you can prevent frost penetration.

My house has a horizontal/flat styrofoam apron around it. It stops the ground from freezing below it.

 

[Egon]

Check your elevations again. If the drain line exit can be placed higher compare cost of new drain line to other solutions.

When the drain line was installed how did you check/maintain the grade.

 

[quicksandfarmer]

I originally used a laser level to site everything out and figure out whether or not the piping would actually come out above grade in that location so they could naturally drain. I'm close to completing just one of the footer drainage pipes - and I've found that my calculations may have been a little off - since it's ending up about a foot and a half or so below grade in that location - and I can't really extend it out any further to make it come out above grade.

Here's what's unclear from your description: Is the spot you want the drain to come out above where the footer drain is? Or is it lower, but not enough lower to get the slope you want? If it's lower, the water will find a way, just as long as you don't have dips where it can pool and freeze solid. You're really best off redoing the pipe with less slope to have it come out to daylight.

If the spot where you want the water to come out is above the footer drain, you can use a pump, pick a new spot, or try to disperse it underground. Reliably dispersing it underground is not a trivial task. Think of a septic system, that's basically what it does, it's designed so that on the wettest day of the year it can absorb water without leaking or flooding. A moderate-sized septic system might be designed to absorb 500 gallons per day. An inch and a half of rain over 1000 square feet is a thousand gallons. A pit full of sand and gravel isn't going to work for that.

 

[jim_wilson]

Here's what's unclear from your description: Is the spot you want the drain to come out above where the footer drain is? Or is it lower, but not enough lower to get the slope you want? If it's lower, the water will find a way, just as long as you don't have dips where it can pool and freeze solid. You're really best off redoing the pipe with less slope to have it come out to daylight.

If the spot where you want the water to come out is above the footer drain, you can use a pump, pick a new spot, or try to disperse it underground. Reliably dispersing it underground is not a trivial task. Think of a septic system, that's basically what it does, it's designed so that on the wettest day of the year it can absorb water without leaking or flooding. A moderate-sized septic system might be designed to absorb 500 gallons per day. An inch and a half of rain over 1000 square feet is a thousand gallons. A pit full of sand and gravel isn't going to work for that.

I guess I can't give the exact answer to that question - because the majority of the piping has been in the ground for about 4 years now - and I'm just getting to finishing it off now. The simple answer is - I put as shallow a grade on the pipe as I thought I could get away with - and now that I've extended the pipe close enough to the spot where I intended on having it drain - I've found that the end of the pipe will end up about 18 inches below grade.

I REALLY don't want to dig the whole pipe up again as just an exercise to see if I can lessen the pitch and get the output end to come out above grade - that would involve enough work at this point - that I'd probably just learn to live with the water problems rather than do it.


What I'm thinking is that I might be able to put in a drywell - which has a "vent" roughly at an equal level to the tooter drain output. The land going away from the corner of my land - continues to slope away - so what I'm thinking is that in most cases the water could dump into the drywell - and percolate into the soil. During the very wettest parts of spring (that's when I see the real water problems) - the "vent" would give the water an avenue of escape - and even though it might back up into the pipe - because the pitch on the other side of that vent slopes away - it might tend to give the water a path of escape.

I'm pretty confident the underground dispersal isn't going to work at those times of the year when I'm most trying to deal with the water issue. I think the ground here gets pretty well saturated - which is why I'm trying to drain it and direct it away.

The underground dispersal would work during the rest of the year - it's dry going down at least 6 feet from what I have seen. But even now if I go down 3 or 4 feet and we get a good rainstorm - I'll end up with a nice pool of water at the bottom of that hole that can persist for a week or more. During the summer - you might get a puddle - but it's gone in an hour or two tops - as soon as the water can sink into the soil.

 

[quicksandfarmer]

One thing to consider is continuing the pipe until it breaks grade, but switching to perforated pipe. That way the pipe won't pool water when the ground can absorb it, but also provides a way out when there is far more water than the ground can absorb.