[Firsttimediyer1]

I'm installing a downspout drain pipe under a concrete walkway to the street and discovered sprinkler pipes running along the walkway one on top of another. There's 3 sprinklers pipes on the inlet side, and 2 on the outlet side. I already dug 3 feet, the bottom pipe is 10" from the ground (inlet side). After the pitch, the other end of the drain pipe is so deep, lower than the curb, will the water back up? Do I need a catch up basin at the end? Was thinking of using pcv pipe instead of corrugated. The length from the downspout is about 29 ft. Will post pics. if needed. Thanks.

 

[Yodaman]

Are you sure you are allowed to do this? Rules are getting strict about runoff into the storm drains.

The water needs someplace to go. A catch basin only collects debris. It is not the destination.

You might consider draining into the lawn somewhere. Preferably somewhere the low end of the pipe is above ground.