Here are a few notes on connecting the project:

1. Do not put the sensor to near to the irrigation nozzle.

2. Be careful around the highvoltage AC and isolate the relays from the rest of the project.

3. Becouse Raspberry has no analog inputs you can use digital output pin (DO) on sensors controller. The controller has a neat treshold regulator and labeled on the image.

Other options include analog/digital converters and arduino/avr microcontrollers, but i won't use them this time.