During times of heavy rainfall, my basement toilet water level rises to to brim of the bowl. The water appears clean (although is may only appear that way). There is a shower right next to the toilet, but water does not come up through the shower drain. I can scoop the water out of the toilet and put it down the shower drain and it seems to drain away properly. Any thoughts on why the water rises? Thankfully it hasn't overflowed yet. We just don't use that toilet during these times.
Thanks

Do you have any stairwells or patios that have drainage openings? Are your gutter down spouts piped under ground. Is the basement level where the toilet is located the lowest level in your home?

Are you on septic or city sewer?