Hi there everyone!

I’ve got two structures, 2000 SF and 1000 SF that I need to drain about 100 yards to the back of the yard, where it will dump into the woods. The way the structures are oriented, I will probably be initially grouping two downspouts(I have a total of 8) for four initial lines that I need to do something with.  I’ll also be adding a couple ground drains as well.

I’ve done a ton of Googling on what pipe to use and everyone just seems to keep adding 4″ flex pipe from the box stores until they’ve got enough drain line for their needs but is that the best way to handle this?  Should I run a total of four 4″ flex lines to the back or should these be dumping into a single or pair of larger lines?  To add to my concern, I’ve also looked at a lot of video where the flex pipe has both been eaten by rodents and crushed flat inground, causing the system to fail. ( https://www.youtube.com/watch?v=5j9bWGt_Vwk )

I really don’t want to do this job twice.  What’s my best bet for a usable solution to drain this much water?

Thanks for your time!