Following a prolonged heavy downpour last week I came home to find my cellar full of water. This water was full of dirt and grit (and smelt unpleasant). I immediately unblocked the drain outside the cellar door (where this water must have come from) and the water immediately drained away. Further to this I know my neighbours also experienced this problem. To my knowledge this has not happened before, can anyone tell me why the water came back up the drain and how I may stop this happening in the future?