William Morris wrote:

Actually, where I live, it's required by city code to have a pipe running
from the tpr to within a few inches of the floor. Oddly, they don't care
much if you have a drain for that pipe to run to...

- Wm

The requirement is there so that discharge of scalding water/steam
from the T & P is less likely to strike someone standing nearby.

Codes usually require that a "suitable" drain be provided for
the discharge but the locals may be convenientally overlooking that.
Jim