Explanation
A water sensor is a type of environmental sensor that detects the presence of water or moisture in an area. A water sensor is most needed in a network main distribution frame (MDF) that is located in a basement near underground fiber-optic cables. A network MDF is a central point where all the network connections converge and where network equipment such as switches and routers are located. If water leaks into the basement and damages the fiber-optic cables or the network equipment, it can cause network outages, performance degradation, or data loss. A water sensor can alert the network administrator of any water intrusion and help prevent or minimize the damage. References:
https://www.comptia.org/training/books/network-n10-008-study-guide (page 446)