I sold property for years and know Koca Calis pretty well, but I couldn't tell you where the risk area is. Two identical houses facing each other might not both have the problem, and I also suspect that as development takes place, the area of flood risk alters. Builders often like to build above road level for example, thus ensuring that a proportion of their rainfall ends up as someone else's problem.
The best advice is to view in a storm, or to return and knock on neighbour's doors. They tend to tell you exactly what the situation is in that specific part of town - not least because they know if they don't, you might be their (angry) neighbour soon.