@TD22057 thanks for reply.
I worked out that I need to connect red to +5V and black to GPIO Analogue input. High value 1024 means there is water < 800 means its dry.

@TD22057
Hi, I've sourced same water detector and electronic value.
I can't seem to work out how the water sensor functions - i notice you wired it to 5V on red and black to D4, but is there a trick in terms of how it works ?

I assume you are reading the D4 pin in your code ? Could you pls help out/share your code ?
How you finding the reliability of the sensor and value ?

kinds regards
mars000