I purchased "pop-up" drain emitters from Lowes for the drain ends. They were about $12 each and consist of a 90 deg 4" fitting and a cover approximately 8" in diameter that sits flush to your lawn. The center of the cover simply pops up when the water level gets to it. They handle the heavy rains here in S. Louisiana with no problem. They have worked great. The top can be lifted off to remove debris if necessary and you can cut right over them with a mower! The rest of my installation consist of the 4" solid flex pipe and fittings connected to aluminum downspouts via round to square adapters. Average cover of the buried pipe is only 3 - 6 inches and has not experienced any problem even with my tractor frequently passing over it. I am really pleased with the low cost, ease of installation and quality of this combination.