How to divert rainwater underground towards road

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Posted by: from Ayr
11/15/2012 at 4:15:44 PM

How do I build an underground pipe run to take roof rain water from downspout to the road?

I have seen them around but will it not freeze in the winter and be ineffective?

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Date/Time11/15/2012 at 5:27:19 PM

Before you go through the work first consider the following:

1) Does the municipality where you live allow water to drain onto the streets? Many municipalities are now requiring all water be self contained on the lot by using rock pits, etc. You may see people running their drainage on to the street but this does not mean it is allowed. If it is allowed then...

2) Is there an advantage to running it on to the street over using a rock pit? Rock pits are very effective and not that expensive, depending on the rainfall in your area it is as simple as running a 4" PVC pipe from your downspout to a rock pit placed at least 16'-6" away from your building foundation. The PVC pipe should be installed with an adequate slope to prevent water sitting in the pipe. Again the rainfall in your area will determne the size of the pit, in general a 36"x36"x36" or 60"x60"x60" hole below your foundation level filled with 1"-2" aggregate and covered and wrapped with landscape fabric is usually enough. Also check the frost depth for your area, most places in North America have a frost depth of 24", you should place your pit below your frost level to prevent freezing.

A Rock Pit or Dry Well typically contains the following components:

1. Stone shall be 2-inch to 1-inch uniformly graded coarse aggregate (Size No. 3).

2. Landscape fabirc or Nonwoven Geotextile shall consist of needled nonwoven polypropylene fibers.

3. Topsoil to cover pit.

4. Pipe shall be continuously perforated, smooth interior, with a minimum inside diameter of 4 inches. 12 gauge aluminum or corrugated steel pipe may also be used in Seepage Pits.

5. Gutters and splashboards shall follow manufacturer's specifications.

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Date/Time11/15/2012 at 6:12:02 PM

I would recommend installing a French Drain. This is simply a hole dug beside your house below the frost line. You fill the hole with stone up to near grade level and then just use soil. You direct your downspout into hole which will then disperse the water into the water table.

The only consideration you have to be concerned with is making sure your downspout does not freeze.

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Date/Time11/15/2012 at 6:32:36 PM

Trench needs too be dug too the frost line, usually around 3 ft deep with a weeper pipe installed at bottom, sometimes refered too as a french drain pipe is covered with gravel and then backfilled too grade.

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