I've been seeing water infiltration problems in my crawl space/open basement. The house is built on a cut & fill lot, with what I suspect is a sloped sandstone formation underneath the house.
I'm in California, where it doesn't rain often, but we've been having some massive storms recently, and this has been causing the basement to start filling up with water. As it's an open basement, this water infiltrates into my garage, and messes up drywall/finishings.
One of my options is to install a sump pump in the basement, but that doesn't seem like the best solution as that means water still gets under the house and potentially getting some of the wooden framing wet. In addition, I'm worried about the flow of water causing erosion of the soil under the house. I considered a surface french drain in the yard as well, but wasn't sure that would be at all effective.
I was wondering if anyone had any solutions that I could look into for controlling the flow of water into the house.
I've attached a diagram of the landscape.