I had a nasty water leak in my kitchen about two years ago. My cute little point-of-use kitchen water heater sprung a leak, and it did some major water damage to the room directly below.

To help ensure this would never happen again, I installed a pan for my next water heater below the sink, along with a water sensor. If the water sensor gets wet, it sends a signal to a control valve at my water main, which then shuts off all of the water to my house. This system is made by Guardian, and can be found here: https://amzn.to/46QTRfB