As the winter storm thaws, the next hurdle for San Antonio is water supply.

Nevermind that the San Antonio area is under a boil notice until further notice. This is about bursting pipes.

Water inside the pipe freezes, which causes the pipe to burst. Once the water is no longer frozen, you get flooding. (Reddit has a scary-looking photo of a Dallas apartment building that's drenched.)

Pipes are supposed to be buried beneath the frost line, an invisible line that indicates how deep groundwater is expected to freeze. In Texas, pipes are generally buried anywhere from 1 to 2 feet, which under normal winter conditions would not pose a threat. Unfortunately, this was not a normal winter storm.

If you think you have a problem, go ahead and call a plumber (especially since they're backed up and you may wait a few days). But if you don't know, here's a checklist on what you can do to find out.

How to tell if your pipes are frozen

• Look around faucets and other plumbing (toilet, washing machine) for drips or areas that are wet such as damp drywall, rings on the ceiling, and pooled water.
• Look in unexpected areas of your home that are unheated such as crawl spaces, attics, and garages are particularly susceptible to freezing.
• Check if your plumbing is working normally. If the water isn't running or if it has an odor or discoloration, that's a sign a pipe may have burst.
• Check your water meter. If it shows movement and you're not running any water fixtures, that's also a sign a pipe may have burst.

If you find evidence that your pipes have burst, then you're advised to shut off the water at that location, or else shut it off at the main valve, to prevent further expensive damage.

How to access your water meter

Water meters in Austin are usually located near the curb in front of your house, with a direct line that connects to your outside faucet. So look in the vicinity of your outside faucet.

The meter is underground and can be spotted by its heavy, round manhole-style lid (usually marked "water").

You can use a screwdriver or other large metal rod, but there's a spring underneath the lid that you need to unlatch, just like a doorknob, and water meter keys have a little notch that works perfectly.

Hardware stores sell water meter keys specifically designed to remove the lid. There's one kind that looks like a giant, old-fashioned skeleton key; the other is a long bar shaped like a T.

How to shut off your water

If your leak is specific to one area such as your toilet, there are mini-valves where you can shut off the water supply just for that one area.

If your problem is bigger, you'll want to shut off the main valve. Here is a helpful video showing how to do it.

Then it's just wait for the plumber to arrive.