I understand not to dump my gutter runoff into the French drain pipes, but what I am curious about is can I utilize the same trench and "stack" the pipes?

So it would be, starting lowest to highest (excluding the fabrics)
1. Gravel
2. French pipe
3. Gravel
4. Gutter drainage (solid pipe)
5. Gravel
6. Topsoil

Or, is this a bad idea and will make the French drain less effective? In which case, I would need 2 parallel drain lines that I can "Y" together farther from the house.

I will be having a small backhoe doing the trenches, so it will not be much of an issue.

If they must be parallel, I would presume that the storm water drainage should be farther away from the foundation than the French drain? My plan was to have the French trench 4 feet from the foundation to drain a soggy yard as well as keep water from seeping into the basement.

Thanks for the help!

So...assuming I'm right in my assumption, that is what we do up here in one of the wettest climates around. Just be sure your top pipes (the rain leaders) are deep enough to allow someone to cultivate the beds. It passes code, just make sure you have the right pipe if you are going under a driveway.

Oh, and by "gravel" I hope you mean drain rock.
And by "French" pipe, I hope you aren't referring to that black corrugated stuff.

We use the same white (PVC, I think) pipe top and bottom, 4" for the foundation, 3" for the rain leaders.

Glue it all, slope it all and for goodness sakes wrap it all...I still see folks laying newspaper down

I wrote: "We use the same white (PVC, I think) pipe top and bottom, 4" for the foundation, 3" for the rain leaders."

Need to be certain you know this; you use perforated pipe for the perimeter drains and solid pipe for the rain leaders.

And remember, clean outs are your friend. Put them in and use them.

Yes, by gravel I mean drainage rock.

Now for the pipe, I'm using a combination. PVC for the north side of the house, which will contain cleanouts and the rain leaders in the same trench. So perforated PVC for the "french" line and solid for the rain leaders.

On the south side, I am using the slotted black corrugated because it will be buried entirely and empty into a gravel bed. I went back and forth on this one but figured since it will be entirely burried, socked, and have landscape fabric around it, I would be safe going with the cheap (and easy) alternative. Any thoughts on that approach?

The black, corrugated stuff works, it just collects debris. Rain washes granules off the roof, your gutters carry organic stuff down and all that catches in those ribs.

Drop a chunk of cement and some other construction rubble down a downspout, have your fabric allow a bit of fines to sift through and before you realize it it slows up enough to back up.

Then you have to power jet it or dig it all up and replace it.

I can see a production builder using it for cost reasons but we do a house every year and a half (new) and maybe reno one or two others in that time and if we have to do the drains we use PVC. Its done once and forget it.

I like the forget it part, especially if we retain the home and rent it out.