Find the main valve where water enters your house, usually near the street, in your meter box, or along the front foundation. Turn it clockwise until it stops turning. This cuts water to the entire house. If the valve is stuck or you can't find it, call a plumber immediately.
After closing the main, switch off your water heater at the breaker or pilot light. This prevents the heater from running dry and cracking once the supply is shut.
Go inside and open a hot and cold faucet in your lowest-level bathroom or kitchen. Let water run out. This relieves pressure in the lines and stops water from spraying out once you've shut the main off.
Copper and PVC pipes under Soquel homes fail for several reasons: corrosive soil, ground settling, or pressure spikes from the local water system. Sometimes a pipe just gets old and splits. The first sign is often wet spots on your floor, a musty smell in the crawl space, or a sudden spike in your water bill even though you haven't changed your usage. By the time you notice pooling water, the leak has already soaked the foundation and floor joists.
A burst pipe doesn't repair itself. Water keeps flowing until you shut it off. A plumber will come in with moisture meters and a camera to locate the exact break point under your house. They'll expose the damaged section, cut out the bad pipe, and install new copper or PVC. If the break is major or in a hard-to-reach spot, they may need to open the floor or crawl space. The job takes a few hours for a simple repair or longer if damage is extensive. They'll also let the area dry and check for mold before covering it back up.
Don't wait to get this inspected. Every hour that water sits under your house is an hour closer to rotted framing, collapsed insulation, and mold growth. Mold remediation costs far more than fixing the pipe. A plumber can arrive in about 45 minutes and get you a price for repair before any work starts.
Describe what you're seeing to a real Soquel plumber: call (831) 555-0135 or send the form. Free, no obligation.