Iknow you're gonna do it with pipes, but some carefully use
a tiller and a string level, making a gentle and manageable
drainage swale. With plastic from the house, out about 8 feet,
and the dirt used to make a positive slope from the house,
covering the plastic far enough so it gets away from the house.

But anyway, you can convert to 3" pipe after the downspout
transition. Easier to bury. Use good leaf guards up above.

On Mar 13, 4:59*pm, Eric Keller wrote:
My first post to this group so please forgive me if this has been
asked and answered.

I plan on burying my downspouts and having them merge into one 4"
drain pipe. The discharge will be at a nice point far from my house.
The length will be about 200 ft from the first downspout to the
discharge. There will be a total of 4 downspouts merging into the same
line.

My question is: How many downspouts can I run into a single 4" PVC
pipe within the 200 ft length? I live near Chicago and we get plenty
of rain.

Thanks.