What do I do when the toilet is overflowing? That's a question I got when a tenant called this month. The tenant was panicked, asking me how long till I arrived. Keep in mind this was on the 3rd floor... I calmed the tenant down and stated that to stop the flow of water, the first thing to do is to turn the water supply line off, clockwise. Under panic, of course the tenant was still confused after detailed explanation. But upon arrival, I saw that the tenant calmed down and turned the toilet water supply valve off. To my amazement, there was no other water leaking as it went straight down to the basement, rather than the other units below. So next time the toilet floods, take a look at this hose coming from the wall and into the toilet. Simply turn the valve clockwise to stop the flooding! And of course, call a plumber or a handyman to rod the toilet :)