Many people do not realize that you can prevent a toilet from overflowing simply by kneeling next to the toiling and closing the water inlet valve by hand. Often they believe their only option is to plunge the toilet before it overflows. Even after learning this it is often forgotten during the next flood.
To resolve this problem I devised a method of using a simple foot actuated valve to close off the incoming water pressure in an emergancy flood situation. The valve is piped in between the water inlet and the toilet. If the toilet begins to flood then you simply step on the plunger and the flooding will stop. This will give the person time to find the source of the flooding without feeling rushed. To restore proper water flow you simply pull out the lockout pin and the plunger returns to the original position.
There are other flood prevention devices on the market today, but they are complicated and expensive and most of them are found in specialty catalogs only. This product could be sold in any hardware store for a minimal price.