This is probably because all the gutter drains are connected to

drain pipes at 4 corners of the house and then these drain pipes converge under the concrete floor to a main drain. This is not a very smart design (many old houses have that) because the drain under the concrete can be blocked, and there may not be an easy way to snake it. 

To prevent future occurance, disconnect each gutter drain from the drain pipe into the house, fill the drain pipe with concrete, and extend the gutter drain to drain to the yard directly.