Side Lean /Drains Flooding

Hi All,

I own a property with a side lean within the side lean there is a manhole cover and 2 drains, each time there is heavy rain one of the drains floods into my side lean. The drain is not blocked and I have asked Severn Trent to see if they can redirect the pipes and told no. I've tired to use sand bags and they are useless due to the amount of water coming up from the drain. The drain is pretty deep so I'm surprised the water is rising so high.

Does anyone have any suggestions on what I can to stop the flooding? Even if it means bringing in a private contractor.

Just to add the property was like this when I brought it and there of course was no mention of flooding ect in any documents.