In the lower level(basement) of my raised ranch I have roughed in plumbing drains for a second toilet and shower. The problem is that the drain for the shower has holes drilled in it about a foot down. and when it rains heavy the outside water drains through these holes and down the drain. The top of the pipe is at floor level so no water enters my basement, but is this normal practice for backyard draining and what are my options for finishing this bathroom?
Wow I never heard anything like this in my life. NO IT IS NOT “NORMAL” to have holes drilled into a waste line. What I think you have here is some not to bright person may have drilled these holes for under ground seepage when the water table rises.
I would take this mess out completly and repipe the drain properly. If someone has a water condition that is a concern they could install perforated piping leading to either a sump pit or another means of LEGAL disposal.
You could for example install a storm water drain that enters a trap within 15 feet of a vented line and have it discharge to a soil or waste line IF local codes permit. What may happen in the future from the piping arrangement you now have is your shower waste can fill up with silt and render you in a whole big drain cleaning mess. Think about this for one minute, IF the ground water table is not entering this pipe then it is very possible the drainage from the shower is getting under your basement floor either under mining it OR worse making a breeding place for all kinds of bacteria and thus causing a great place for smells to start coming from. Good luck