Here is a smart sensor that helps you catch leaks at home and avoid costly accidents. The Fibaro Flood Sensor is a HomeKit enabled device with a water and temperature sensor. It responds to Siri to let you know the status of your home via voice. It combines with smart lights to get your attention. The acoustic alarm also helps.
The Flood Sensor helps protect your home from potential water damage. It also lets you avoid frozen pipes. You can get one of these for under $70 at this time.