Rain runoff from upper neighbour

[Sinan M.]

Hi everyone,

I need your help to try and understand my options. I have a tenant who is complaining about water coming from his upper neighbour (mainly when it rains). As you can see in the pictures, it comes under the red fence and also through the wall. 

I brought in my handyman who does not think he can help, as the slope on my property is not steep enough to redirect the water to the back, so it stagnates. 

Is this an issue I need to bring up with the neighbour? I'm curious if some other landlords here have faced similar issues.