I live in Michigan. We have been slammed with snow, that is just now beginning to melt.
Yesterday I noticed, when I wash my basement toliet overflows and lets in a sewer smell

. Then today when I gave my infant a bath and drained the water out the basement toliet overflowed again with the same stinky smell.
That half-bath is not in use and the water valves are shut off because of previous overflowing issues.
Help!!!