In many places in Texas, the soil can ruin foundations of single-storey buildings if allowed to cycle between wet and dry. To overcome this, watering the foundation is a requirement to maintain a baseline soil humidity level. Snails thrive in damp conditions.
This is mostly a myth. It's impossible to actually keep only the soil underneath one's home a consistent degree of wet. If you water the soil under your house, the water eventually gets sucked out by capillary action to all of the dry parts of your lawn (and your neighbors lawn).
It would only work if everyone watered EVERYWHERE, by a uniform amount.
