Drainage Pipe placement

It's not clear as to how the runoff from your driveway will get into the pipe you suggest. Is it your intention to pick up the runoff with the installation of a catch basin or other surface drain which will then be connected to this pipe? Or is it your intention that this pipe pick up the runoff along it's entire length? Is it to be installed parallel to the driveway, and right next to it?

I apologize for not explaining in a more detailed fashion. The runoff flows downhill from the driveway, then cuts across the backyard to a "wetlands" area in back. That flow of water is smack dab in the middle of where the arena needs to be enlarged. So, basically, there is no need for a pipe in or next to the driveway, but there is a need for a pipe on the grassy area of the backyard before the fill can be added. Water should take the least restrictive route and flow right into the pipe, so I've been told.

If you can, what you should do is to find the spot that will be the lowest in the remaining grassy area after the fill is placed. That is the place where the water running downhill will collect when the fill creates a dam in its way. Once you've determined where that will be, visit your local big box home improvement store and see what they have for "in-line" catch basins. These are usually plastic like structures (some are PVC, but more often HDPE - high density poly-ethylene) that come in a variety of sizes and shapes. The home improvement folks may only offer a couple, but that's fine. Get one of those along with sufficient PVC or HDPE pipe to extend from the "low point" to the place where you will have the new pipe "daylight" (ends, and water flows out). You'll then be faced with diggind a hole larger enough and deep enough to install the catch basin at that low spot, and a trench deep enough and long enough to install the pipe from the catch basin to the outlet point. These materials can be installed and bedded with gravel, so you may not have to purchase special "pebbles or stones".

Now, that's what you do if you're intending to take the water straight from point "A" to point "B". If it's you're intention to infiltrate the runoff into the native soils along the way, you'll need to first determine what kind of soil you have, and whether it will "perc" (allow the water to drain out of the pipe and into the soil). Gravels will do that. Clays will not. If you have clay, then infiltration isn't for your project. If you have gravels, replace the pipe you buy with a similar product that is perforated along its entire length, and purchase sufficient 3/4" washed crushed stone to back fill under, around, and over the pipe about 4-6 inches. Then fill the remainder of the trench with native earth removed from the trench.

Long winded...hope that's what you're looking for.

[This message has been edited by treebeard (edited April 23, 2003).]