Caliche is the reason
If you are new to the Hill Country, this is the thing nobody warns you about. Caliche roads and drives are firm, pale, and reassuring in the dry. Add rain and the top layer turns to grease over a hard base, which means you get all of the sliding and none of the digging in. Vehicles do not sink so much as slide, and they slide toward whichever side drops away.
Wimberley Towing pulls vehicles out of this every week, on the ranch roads around Wimberley, the caliche drives out to the acreage properties near Dripping Springs, and the county roads through Blanco.
Low water crossings
These deserve their own warning. A crossing that is ankle deep can be moving water within minutes of a storm upstream, and the water does not have to be deep to move a car. If you are already in one and the vehicle is not moving, get out on the upstream side if you safely can, get to high ground, and call from there. Do not sit in the car waiting to see what happens.
Once the water is down, the recovery is a winch job, and the car is going to a shop rather than home. Water in the engine or the electrics is not something a tow fixes.
What we do about it
Line, an anchor, and an angle that pulls the vehicle back the way it came rather than dragging it sideways into the thing it slid off. What we do not do is put a strap between two pickups and hope, which is how people get hurt.
Call (512) 375-1215 and tell dispatch what the ground is like. Part of our off-road recovery service, alongside winch-out service.