Buried downspout

[JimBinMI]

Hey all,

We're doing some landscaping at one end of the house where the downspouts from the eves comes down and angles then empties on the surface of the ground. I would like to bury perforated pipe and have the water drain that way, so that it dissappears into the ground. Any ideas on what type of pipe to use and how far to run it or how deep to bury it?

Could I use one of those 3 pt. implements to dig the spot for it, I can't remember the name of it but it looks like a narrow plow that appears to go fairly deep.

Any suggestions would be appreciated!

Thanks, JimBinMI

We boys and our toys!

 

[Von]

Jim,
I would have it come out at grade down aways if you have a slope. If you are going to bury the whole thing you will need to put in either a french drain or a leach line to hold all the water during a downpour.

 

[Bird]

JimBinMI, I think the implement you're talking about is the "subsoiler." And you can make a bit of a narrow trench with it all right, but I agree with Von; think you need to put in a French drain.

Bird

 

[Kevin_mc]

I agree with Bird it sounds like your looking for a sub-soiler. I had a hard time finding one in my area until I was explaning to someone what it looked like and learned that most of the folks around here call it a "ripper". Once I used the local term I found it much easier to locate one in my price range.

A single heavy duty ripper (really beefy one) requires min of 20hp. The economy ripper requires less hp.

Kevin

 

[JimBinMI]

Von,

OK, don't know what a "French Drain" is or a "leach line"!

I do know that about half of my front roof line empties into a downspout that goes into the ground and comes out (just can barely see it at the surface about 50 ft. away.

My plan was to not have the water pour into the area that we are going to landscape with plants, trees and mulch. It does come out on a slope. I suppose that I could just extent the downspout and cover it with mulch in the area to be landscaped, if that didn't look too goofy!

By the way, the implement that I was thinking about was a Middlebuster, TSC advertises it as a one row 15" plow, price is/was in the old ad I found $89.99

JimBinMI

We boys and our toys!

 

[Bird]

JimBinMI, I have one of the Tractor Supply middle busters ($99.99 in my 1995 catalog which is what I paid for it that year). I use it occasionally to make a trench and I use it to dig my potatoes. On the same page of the catalog, they have a subsoiler for $139; narrow shank, 36# heavier, about 7" taller (get deeper in the ground?), etc. I occasionally take the plow off my middle buster and bolt on a single heavy duty ripper tooth to dig deeper, narrow trenches.

Let's see if I can explain a French drain, or if someone can correct me. You dig a trench 1' to 2' wide and deep, put a little crushed rock in the bottom, lay in perforated pipe (with your downspout running into that perforated pipe), then cover it with crushed rock, put some kind of screen, net, roofing felt (I've known of various materials used), over that, then cover it with dirt. In other words, you're making a leach field very similar to the one a septic system uses. Size depends upon how much water you expect to run into it. They are not used much in my part of the country, so maybe someone else can tell you more, but they are occasionally installed parallel to the building, i.e., around the foundation of a slab foundation building to keep it watered so the ground doesn't dry out and let a foundation settle and crack.

Bird

 

[TomG]

Four inch flex drain (aka 'Big O') works well. It comes in perforated or unperforated. The perforated can be used for a leech line. A leech line is just a length of perforated pipe. The line usually is fairly large diameter to provide some storage capacity, which allows time for water to percolate into the soil.

A closed system has to have storage capacity to allow for wet years when percolation rates are low and for heavy rainfalls. A French drain is something that provides storage capacity. As far as I know, it's a pit in the ground that is surrounded by sand is filled with cobblestones, or can have a cavity made with cement block walls (the joints are not mortared and the holes face outward). What distinguishes a French Drain is that it has an impervious bottom.

A French drain usually is used for gray water or small flow septic uses. The idea is that the impervious bottom forces waste to percolate sideways through sand before it can enter the surface water table. You shouldn't have to worry about water table contamination from roof runoff, and an ordinary leeching pit (without an impervious bottom) would work.

An open system is easier to design than a closed one. The idea is that water can run out on the surface if the storage capacity is exceeded. A simple system might be: Take a 55-gallon drum and cut a hole for the fill pipe in the side near the bottom. Dig a pit where the ground level is below the downspout. The pit should be deeper than the drum is tall. Dig a trench to the pit for the feed line, install the drum (bottom up and without the top) in the pit, and run perforated drain line to the drum. Install a sizable vent line from the drum to ground level and backfill. Any excess water will exit the system through the vent. It's a good idea to screen the vent to keep out bugs and small animals.

If you're in a snow area, keep in mind that these systems do freeze, and your spring roof runoff will happen before the system thaws out. The only way to keep such a system open is to run the feed line straight down from the downspout to below frost level, and insulate the upper section. I don't think that's a good idea, because a joint failure could put a lot of water right on the middle of a foundation wall. I'd just put up with the freezing and disconnect the downspout after freeze up.

Another version of a system might use a drum for storage, and then run a leech line from the top of the drum. Then, you've got gray water storage, and you could install a pump and use the stored water for landscape plants. Extra care should be taken using even roof runoff gray water for food crops.

Keep in mind that there may be local codes that govern the design and installation of gray water systems--even for roof runoff.

 

[Anonymous Poster]

Jim, I have installed many buried downspouts and I do it this way. First I only use schedule 40 pipe since it only cost pennies more. Anything less can get crushed with heavy equipment driving across it; since it is only buried a few inches below the ground surface. Extend you pipe at least 6'-8' beyond the house to properly drain the water away from the house. At the end of the pipe I install a small drain basin & grate that is attached to the 3" or 4" schedule 40 pipe and place the top of the drain grate at ground elevation. The force of the water will push the water up thru the drain grate. The best way to do this is with a narrow backhoe bucket or the old fashion maddox. You need to install the pipe just below the ground surface allowing the drain grate to be flush with the ground and allowing a slight pitch of the pipe. A french drain would never allow for all the volume of water. Good luck and don't let anyone talk you out of anything less than schedule 40 pipe(either 3" or 4"), since I have had many people use something different and have afterwards said "you were right" when the equipment crushed their pipes.

 

[Bird]

I believe that sounds like the best idea, yet, Jon S.

Bird

 

[TomG]

Just a quick comment: I agree with the suggestion. From the original question, I thought there was a problem with simply letting the runoff go on the ground but further away from the house. Some storage capacity (pit or lines) would eliminate runoff on the ground from moderate rainfalls.

Trying to be helpful, I'll note that there is an assumption that 6' - 8' from the house would be below the bottom of the downspout. If the drainage grate isn't below the downspout, water will come out the downspout unless the spout/drain pipe joint is watertight. Some rural houses weren't built with the best grading.

We went about 20' under a porch and across a drive and have maybe 3" - 4" of angle. The drainpipe under the porch actually is above ground level. Some runoff drains into low spots in the yard, but the angle isn't enough to give good drainage. Some of it runs back and down the drive. Some of it drains back into the trench under the drive, but at least it gets to leech on its way back toward the house. The above ground section keeps it from coming all the way back to the house. All told, it's still a lot better than having a pool at the foot of the porch and across the drive. And, it's easier than re-grading the house. It's certainly easier than installing lines or a large capacity pit.

To illustrate storage capacity requirements: I built a gray-water leeching pit at our camp. The soil is sandy, and requirements for a pit rated at 1000 liters a day still are 4 x 2 meters by 1 meter deep. Two foot of the depth had to be above ground since our high water table is about 4 1/2 foot. The pit has an internal chamber of about a cubic yard and is surrounded by 8 yards of septic stone. This is a pretty big thing, but at a 1000 liter rating, it isn't going to handle runoff, except maybe from a playhouse. We use the drum type
dry-well I described for laundry, dish water and sump discharge at our other place. It's appropriate for gray that you can't just run out on the ground. It still fills up on heavy laundry days.

I don't know how strong schedule 40 pipe is. I was looking for small diameter steel culvert to run under the drive, but couldn't find any. I ended up building a 3 sided box from 2"x 6" and running 4" flex drain through it as a temporary measure. That area of the drive doesn't get much traffic, but the tractor and 1/2 ton haven't crushed the flex drain yet. Sometimes temporary becomes permanent.