Sacramento has been in a drought the past few years, but this year the flood gates have opened up. Yes, WAY above average, finally. I always point out the possible drainage issues a home may face that are apparent when I show a home. A few years ago, a Buyer's daughter asked me to stop because "It will obviously never rain again". That so??? But I admit it is hard to think about the effects of rain when you are shopping n shorts and 110 degrees!
Here is why you don't want drainage issues. Dry rot is a fungus that grows on wet wood, and it spreads. Try sticking a screw driver into solid wood - it's hard, right? But try sticking it into dry rot, and it sinks like a knife in a bundt cake. Dry rot will eventually compromise your structure. What about wood destroying beetles and other bugs and critters? They love damp conditions. They will flock to your damp substructure. How do get them out??? Tenting - which is costly. Here's my Monday Minute on drainage.