I wondered aloud whether the soil's retreat might be affecting the crack in my foundation (it's a slab foundation) that appears to be growing (the tile grout is opening up above the crack).
The other passenger in the van said, "Oh yes. The same thing happened to my house until I started soaking the ground around the foundation."
"Whatever you do, don't fill the gaps near your foundation," said the yard sage, our driver; "that'll only cause you more problems when the rains come. The clay can't take up much water when it's this dry, so the water will just sit there. There's nowhere for it to go when we get rain, so it'll just move your foundation more."
Huh, I thought. "Why doesn't anyone tell new homeowners these things?" I asked.
"You're not from Kansas, are you?" asked the driver.
To which he told stories about the natural fortitude of Kansans.
Anyhow, I sense a really useful book for new homeowners. It would include tips such as this:
Water your yard around the foundation during droughts. This helps prevent your house from settling and your foundation from cracking.
EDIT: Needless to say (yet I'm going to say it anyway; I mean, isn't that what always comes after "needless to say"?), I've been soaking the soil around my foundation since I wrote this, and will continue doing so until I've done so all the way around the perimeter. I'm almost half-way done now.