Your simulated presence sensor for " water" would need to show up in the list of presence sensors to make this work. So that would be the first thing to look at.
I think you have to start with the device type of virtual presence sensor and then add the capability.switch to it.
@tgauchat or one of the other coding grandmasters would know. I think @luna might have done something similar for a different use case. I know @joshua_lyon has written about using them before.
Virtual Presence Device - Control from SmartPhone
Sorry I can’t help more, I’m not able to actually read the groovy code because I depend on text to speech.