I need to run my sump pump discharge to a drainage ditch along the
road. The discharge exits the house at 1.5' above ground, but the
grade is almost flat... it's 100' from the house to the drainage
ditch, and the ground itself only loses a few inches along the way
according to an excavator (measured to the bottom of the drainage
ditch).

I currently have a 4" black flex pipe just laying on the ground,
running from the house to the drainage ditch. It works OK (except in
the winter), but is not a permanent solution for many reasons.

Perhaps the obvious solution is to bury a drain pipe. The path of the
drain pipe will cross (and likely run parallel with) several
underground utilities including electric, phone, and cable - so
digging down several feet to avoid freezing is not an option.
Besides, I'd be leary of this approach anyways since the pump would
have to lift the water back up to ground level at the end of the run.

I've been told by an excavator to bury a 1.5" PVC pipe, just beneath
the surface, and try to maintain downhill or at least level for the
entire run. I would probably incorporate a vacuum breaker where the
pipe comes out of the house, to help gravity do its job, as well as
providing a secondary outlet connection for winter use or if the PVC
gets blocked.

Does this sound like a good approach, given the circumstances?

I'm concerned the PVC would freeze and break if it doesn't drain
completely. I'm also concerned about the pipe "heaving" up to the
surface as a result of freeze/thaw.

A neighbor says to bury 1.25" black flex hose a foot down, like he
did... but he has much more vertical drop than I do, and I'd think
flex hose would be more susceptible to having a lowspot than 10'
sections of PVC.

Any comments/suggestions are welcome. Note... this is in southern
ohio, with clay soil and a high water table if that makes any
difference.

thanks in advance!