Gutter and Downspout question - horizontal runs

[Jeraden]

I recently purchased an older property that has the gutters/downspouts draining into the ground into clay/terracotta piping. That disappears somewhere below ground and are supposed to be tied into the sewer system (which I know isn't the way to do things nowadays, but this is like a 100 year old house and in a sort of urban area with a small yard/houses close together). The basement is getting obvious water damage in every single spot where the downspouts go into the ground.
So obviously either the underground terracotta is broken or the whole entire system is clogged. You aren't supposed to drain downspouts into the ground anymore, you are supposed to disperse the rainwater 10 feet from your foundation. 10 feet from the foundation isn't an option anywhere except the back yard.
10 feet from the front of the house is into the street, but there is a sidewalk, so I don't think I can dump water onto the sidewalk. And that's level with the street, so can't go under it.
On the left side of the house is the neighbors property. Like immediately, I think the house must sit on the left property line.
The right side of the house has a little yard, but not that big, and then the other neighbor is right on the other side of that yard.
The back yard is a bit bigger. Probably about 20 feet and then it goes into a back alley. There is a detached garage that dumps it's water on the ground which flows into the alley.
It's a fairly flat lot. It slopes slightly forward towards the front of the house.

Ok, there's all the background info. Now my question/idea. There is nowhere to really dump the front gutters or side gutters that wouldn't pose a problem. I want to take all that water and direct it to the back of the house and into the alley. There is a fence along the back left side of the house. My idea would be to cut every single downspout, and make horizontal runs (with sufficient drop) along the outside of the house, carrying them all to the back left corner of the house. And then use some kind of oversized downspout extension to dump the water into the alley.

HOWEVER, in looking up online, I couldn't find one single example of anyone doing such a thing. Everyone puts their water into a drain and then runs the drain underground to a lower spot. Is there a reason for that? Wouldn't it be easier/more cost efficient to just run the downspouts around the house and put all the water where it's easiest to get rid of it. I realize aesthetically it's probably not as pleasing - having horizontal downspouts running along the outside of the house. But it seems the most efficient and easiest to maintain method. Before I go purchase tons of gutter material (which looks like it's like $1 per foot, which is pretty cheap!), is there anything I'm about to royally screw up? Like I'd have thought I'd have at least found some discussions or examples of people doing it online.
This is the best image I could find of what I'm trying to do -- but for all sides of the house except the front (this house is longer than it is wide).
https://www.wisconsinenergymasters....17/02/horizontal-downspout-e1486720265189.jpg

Any advice or suggestions appreciated! Every rainstorm I'm getting tons of water in the basement currently.

 

[Greenman]

It won't look good, will be easy to plug with debris, will probably leak at the seams, is subject to damage, and will rust out faster because of water sitting in it. If it's your only option then that's the way to do it. Sometimes you just have to make a bad situation work.

 

[Jeraden]

Wouldn't the yard drains be more prone to clogging with debris and be harder to clean out though? Like if I add some cleanout T's in the longer sections, I should be able to just blast them free. And gutter/downspout material is cheap! Was also think I could put some shrubs against the side of the house to kind of hide the long run too.

 

[Greenman]

Yard drains are generally a larger diameter pipe and smoother on the inside. Downspout leader will work, just keep the runs straight and 1/4" per foot of slope. It should be a pretty easy job, though that stuff can be a pain to cut as the sidewalls tend to bend and bind on the hacksaw blade.

 

[Micrornd]

It should be a pretty easy job, though that stuff can be a pain to cut as the sidewalls tend to bend and bind on the hacksaw blade.

Grinder, cutoff disk, like butter

 

[Greenman]

Grinder, cutoff disk, like butter

Indeed. I've also used a portable band saw that does the job well, but a lot of people don't have access to those sorts of tools.

 

[Scarpozzi]

I'd probably call a few gutter outfits in your area that do seamless gutter installs and ask them for suggestions and quotes. Get an idea of how they would handle the situation based on your property and slope....then decide who has the best plan of attack and pay them. That way, if it fails, you can call them back out to fix it.

If you're more concerned with the drainage on the property, check some landscape companies. Many of them dig those kinds of lines. They can probably replace your clay with pvc.