I was about to plant one of the above, but realised that the spot I
had chosen for it was most likely right over a drain, or at least not
too far from it. I had a look at out property details, and although
positions of drains etc are shown on a plan, the locations of surface
inspection covers and grilles do not exactly accord with reality so I
can't trust the plan completely. Nevertheless, it seems there may be
a drain not too far away.

So my question is: would the roots of the Cornus Kousa Chinensis
present a danger to drainpipes etc? I have no idea how far down your
average drainpipe is, nor how deep and strong the roots would grow.
Also, if I were to attempt to keep the size of the tree above ground
in check, by pruning, would that also prevent the root system from
expanding too much, or does it not work like that?

Any help gratefully received.

Mike