For additional protection against possible backflow into your basement, you could also add a floor drain backflow preventer.  Usually these are check valves which are inexpensive and easy to install.  What they are, basically, is a compressed rubber gasket with a floating ball mounted on a spring.  It is installed into the vertical pipe

A reduced pressure backflow preventer, also known as a reduced pressure zone device or a rpz device, is a backfow preventer which, as its name suggests, protects you from your water supply being contaminated by backflow.  There are several types of reduced pressure backflow preventers including a reduced pressure back flow valve, a double check

The ¾ Backflow Preventer is a backflow prevention device used to protect water supplies from dangerous contamination due to back flow.  Most major backflow device manufacturers make these backflow preventers in varying sizes, from the ¾ backflow preventer to the 2 inch backflow preventer, depending on the system currently being used on your water system.