Drainage isn't rocket science. If you can't run the gutter water away from the downspout and foundation via the surface, then it has to run underground. You're talking about a subsurface drain pipe. I have a system that runs all around my house, pool, and spa, and terminates at the curb. I live in NJ, and the pipes are only a foot or so under the grass. Haven't had a problem, but if I was the homeowner that originally did it, I'd have gone down another foot or two. I've got 9 feet of elevation difference between the first drain head and the curb.
If you're really set on doing it underground, you need to collect the following info and post it here.
1. What is the height difference between the surface of the patio at the downspout, and the lowest point of your yard. Hopefully that low spot is the street. You can use the ancient Egyptian garden hose method of checking elevation difference. Post back if you need an explanation.
2. Walk out the shortest route from that downspout to the low point, and make sure there are no utilities crossing that line. In NJ we have New Jersey One Call, where you call them and they come out and mark out all of the utility runs (water, gas, electric, etc). You should have that in your state. Have them come out and do the markouts so you know where your utilities are. Septic is your baby, if you have it, and they won't mark that out. Be careful on that one.
A dry well is also an option, but there are a couple of tests and calculations that have to be looked at in order for that to work. Let's cross that bridge later.
If you're really set on doing it underground, you need to collect the following info and post it here.
1. What is the height difference between the surface of the patio at the downspout, and the lowest point of your yard. Hopefully that low spot is the street. You can use the ancient Egyptian garden hose method of checking elevation difference. Post back if you need an explanation.
2. Walk out the shortest route from that downspout to the low point, and make sure there are no utilities crossing that line. In NJ we have New Jersey One Call, where you call them and they come out and mark out all of the utility runs (water, gas, electric, etc). You should have that in your state. Have them come out and do the markouts so you know where your utilities are. Septic is your baby, if you have it, and they won't mark that out. Be careful on that one.
A dry well is also an option, but there are a couple of tests and calculations that have to be looked at in order for that to work. Let's cross that bridge later.