Meet the mydlink Wi-Fi Siren: a smart device that pairs with your water sensor, motion sensor, and other smart devices to alert you when there is a leak or movement around your home. It connects to your existing WiFi network and has an adjustable volume (up to 110 decibels).
You can control the WiFi Siren from the mydlink Home mobile app. It lets you use Rules to automate your home. Sets you back under $64.