I've installed a new downspout to drain a section of gutter that was getting overloaded during heavy storms. The rest of the downspouts all terminate in corrugated black tubing that's buried in the ground, which prevents the water from simply being dumped onto the lawn where it might pool and work it's way back under the slab. For my new downspout:
- How much pipe should I bury (i.e. how many feet)?
- How much bigger than the pipe should be trench/hole be?
- How much slope should the pipe/trench have?
- Should I put gravel in the trench?
For background on my situation:
- I live in the South. During heavy rains several inches can fall over in only a few hours.
- Our soil has very high clay content so it drains poorly. During a heavy rain as described above the soil cannot absorb the water as fast as it falls so it just runs over top of the lawn.
- The amount of water this downspout has to handle would is approximately a hose at full blast, or close to it.