It sounds to me like the gutters are full of leaves and debris and need to be cleaned out.
Where do the downspouts lead? If they go into the ground are they piped into the the sewer or are they just buried under ground for 10 or so feet where they bubble up to ground surface. The latter is crap. If you move into this house plan on buying new downspouts if it's in a cold climate. They will freeze all winter long.
They could have also piped the rainwater into a (french basin?) That is fancy for a tank buried in the ground which collects the rain and lets it soak into the ground. I don't know much about those. In Michigan the seller's disclosure lists any buried tanks. Check that.