newbie gravel question

[flusher]

I use a 10-ft section of 4" PVC drain pipe (solid, not perforated) with two 4" elbows at each end. One elbow carries an adapter for the gutter downspout. The other has a pop-up drainage emitter (a pop-up valve, the green thing in the photo). Costs about $10 at Home Depot for the whole thing.

 

[flusher]

Oops, forgot the photo.
BTW, I use a self-tapping metal screw to hold the downspout adapter and the drainage emitter to the elbows.