need info on piping a ditch??

[BWS]

we have a 100' section of a ditch across the back of our property that we want to fill in.the grass in this area is pretty wet in the winter/dry in summer.we are thinking of putting n-12 perf plastic pipe in and dont know about the gravel/rock needed or the fabric we need to do this project.can anyone help??do we even need the perf type pipe??bws

 

[lamarbur]

Use to do a lot of new ditches for our highway dep't. We used landscape fabric, stone, and some times glass. You need a much larger pipe than you think. 100 feet can flow a lot of water. Go to yur local hwy and see where they are buying their plastic pipe from. Get 5 lengths of 12" pipe. A foot of stone or glass at bottom, lay pipe, surround remainder w/ stone/glass a foot over pipe, then fill in. Budweiser has a glass palnt in Spfld, MA that rolls busted glass. You can drive over this glass and not worry about a flat tire.. They keep rolling glass until it is almost like sand and no edges. Kind of like miniature marbles.. This stuff packs instantly and can flow water like you can't believe..

 

[BWS]

do i need a foot below the bottom of the pipe or do i just lay the pipe in and fill over it.we will be using rock of some sort i guess.not quite clear on what it should look like??

 

[lamarbur]

I would put a minimum of 6" of stone, then lay your pipe, then fill up around and over pipe another 6",, then fill with dirt. On the hywy dep't we cannot refill the same hole with the spoil taken out, We have to cart in fresh dirt. It has to do with compacting the dirt correctly. For some reason ( and I never was told a decent explanation),, spoil r3eturned to the same hole just doesn't work right. However, I would do it in my own driveway.

 

[Currmudgeon]

</font><font color="blue" class="small">( do i need a foot below the bottom of the pipe or do i just lay the pipe in and fill over it.)</font>

The greatest value of a granular base below the pipe is that you can grade it out and avoid dips in the pipe. Six inches is probably enough. It's hard to place less than six inches of any kind of dirt. Depending on the load over top of the pipe, you'll want to be very careful with backfill and compaction under the haunches of the pipe and alongside the pipe. N-12 is flexible pipe, and it gets all its strength from the backfill.

If there will never be any significant load on the pipe, then the backfill isn't critical.

Make provisions for where the water will go when the storm comes that will overload the pipe. A shallow swale may be enough, but if you don't force the water to go somewhere, it will go where you don't want it - guaranteed.

Open graded gravel, like the crushed glass or pea stone, will carry water. Make provisions to get rid of that water, maybe by putting in some perforations, or the water may appear where you don't want it.

 

[rambler]

If you are affecting anyone else with this project (does the ditch come from other property, & continue on to other property?) then I would be _real_ careful to get the proper permits to do this. You could have one heck of a lawsuit if you create a dam & flood out your neighbors. Some ditches look like they never carry more than a couple inches of water, but are needed every few years to carry massive flows, and if you abort that, you are in trouble.

I'm sure you are doing the right thing, only mentioning this. Here in Minnesota, you can't change a man-made ditch because they are all community owned & maintained, and you can't change a natural creek because they are natural wetlands that can't be touched.

So your project would just be impossible without doing a lot of red tape first, & you would be told exactly how big a tile to use.

In any event, I'd be real scared to just 'guess' at how big a tile to use, unless you have lived there a quarter century & know just how much water flows there in bad times.

Just my experience.

--->Paul