The COWS is built using a Particle Photon as its brains and communication. It uses a HC-SR04 module as the water level sensor.

You might wonder how it uses the sonar sensor as it cannot be submerged. The concept is the sonar will be positioned 3.5 to 4 meters from the ground pointed straight down in the housing, attached to light poles, buildings, etc. During initial setup the device will sense the ground distance and set a baseline. Measurements from this point will be subtracted from the baseline to give the Height of the surface of the water to the ground.

These measurements will be sent to a central server to collect data.