
Lots of rain in Iowa lately. Lots of flooding also. In Council Bluffs, it’s not rare to see people emptying crap out of their basements after a good rain. Here is a shot from my backyard security camera from just last week.
So while I avoid a flooded basement for the most part, I have leaks of the wazoo. I have had the unfortunate pleasure of having either my sump pump floater getting stuck or simply failing which results in more than a few puddles of water. I am sick of having to worry if something is going to go wrong when I am sleeping or when I forget to check the basement so I built a simple water level detector with a water level sensor.

Using an Arduino Nano microcontroller and some other parts I created something that would set off an alarm if the water got too close to the top of my sump.
Parts List
- BC547 Transistor
- 100 ohm resistor
- Arduino Nano
- Funduino Water Level Sensor
- Salvaged 3 ohm speaker
After wiring up the water sensor and checking on a serial monitor what the analog value would be when water first touches the sensor and what value when water is dripping off of it I programmed the Nano to set off a nice loud alarm.
Arduino’s only put out 5 v at their output and that results in a ridiculously quiet alarm which is why I put a cheap transistor into the circuit. The result is something I can hear from upstairs and would probably wake me up at night.




Chris Bond is the owner of this website, the father of three children, the husband of a wonderful woman, and the tinkerer of gadgets. He enjoys gaming, flying drones, and solving problems. His favorite TV shows are Game of Thrones, The Rookie, and The Expanse. He is super smart.