[RickG]

I am asking a contractor to daylight three downspouts out the back of my yard, which conveniently slopes down to a water retention pond.

From what i am reading, this is what I expect:

Bury solid sched 40 or core foam pipes 10" - 12" below grade the entire way. I would like him then to run the final 10' as perforated to allow some of the rain back into the soil (clay) as it we have plantings. I am expecting the perforated to wrapped in some filtering fabric, and then a grated end cap to let water out but no critters back in.

Reasonable?

[Matt Kulp]

Everything sounds fine, but if your set on having the last 10' act as a trench drain make sure he does not use flex pipe. If he does it will eventually collapse. Also, since you have a clay soil you are not going to get very quick drainage into the soil unless you have 6-8" of clean stone under the pipe to hold the water. If you don't, once the clay soil gets saturated it will not allow any other water to penetrate fast enough.

Personally, I would just forget about the perforated pipe and just have it exit into the pond. The water will be flowing too fast to the daylight to get any real benefit from it. JMO

[RickG]

Matt,

Thanks. I suspected that might be the case as I went back and put in clay in the posting.

As always, appreciate the time from the pros on the board.

[AZTLANLC]

If you also want to collect water on the same trench you can install a separate perforated pipe in it, just make sure you follow Matt advice, also I'd suggest against wrapping the pipe with any fabric, and if you wrap the stone make sure it's geotextile and not regular landscape fabric.
I usually don't wrap the whole stone when working on clay only the top before spreading the soil.

[RickG]

Aztlanlc,

Appreciate it. As serendipity raises its ugly head again, wife has chimed in on a rain garden. So, I think i will avoid the extra work and have the pipe, solid now, daylight about 10' from the end of the property, where we will dig out and create a rain garden.

The yard drops about 6' over 60' so there is already a nice slope to 'encourage' the water to head to the water retention pond further back.

Thanks again.