Detached garage

I want to build a detached single brick garage , the garage will replace a prefab garage that I have already demolished, a drain runs along the boundary , and according to Yorkshire water records it goes under where the garage will be positioned , a manhole is positioned in the drive approx 8 mtr from where the front of the garage will be this has an invert level of approx 2.060, I understand that this will affect the foundations of the garage and would like some professional advice as to what I can and can’t do.