My mom had a stroke two years ago she is in a care home and me and my family visit every day my mom has started to imagine that there is water all around her and will not sleep as she keeps saying that the river is up she isn't on any medication just paracetamol i was wondering if my mom needs and medication
This could be caused by a number of things, including a uti. Share her symptoms with her doctor.
How does the staff handle her restless nights? I think I would try something like, "Yes, the river is up. It is up quite high this year. But we have a very strong system to keep the river out, so you and all of the other residents are quite safe." Comfort her and help her feel safe. You aren't going to be able to convince her the river isn't up.
Has your mother shown any signs of dementia, perhaps from the stroke? Delusions are common in some forms of dementia.