Take a look at Coastal Risk ...

Take a look at Coastal Risk Consulting (who, despite the name also cover fluvial and pluvial flooding).  They produce Lidar-based flood risk assessments for individual properties which take into account the variations in freeboard around each property, local drainage patterns and so on that can mean that two adjacent houses actually have different flood risks.  

I would also argue that there is a time as well as a spatial dimension here.  There is a concept to be had of "virtual elevation".  If you have a house 10 feet above flood level and a 6 ft levee, you may be said to have 16 ft of virtual elevation.  If you have the same house with flood pumps instead of a levee, that can move 3 feet of water, you have 13 ft of virtual elevation.  The point being that virtual elevation can change day by day - the pumps might fail or gophers might undermine the levee - in which case your elevation is back to 10ft.  If, as well, you have a blocked storm drain or a building site pushing water onto your property, you may be below 10 feet.  This is not an abstract risk - virtual elevation changes on a given day or month could easily mean that the access to say a hospital emergency rom is under 18 inches of water that no-one had predicted ahead of time.