Why Underground Water Lines Leak (and the Warning Signs)

Soil movement is a major culprit. As the ground settles or expands with moisture, it puts stress on buried pipes, especially at joints. Over time, this stress can crack or separate the line.

Corrosion also plays a role, particularly in older metal pipes. Tree roots seek out moisture and can invade small cracks, widening them. Temperature swings cause the ground to freeze and thaw, which shifts the soil further and can rupture the pipe. A combination of these factors often leads to a leak.

Inside your house, a leak in an underground line can show up as a drop in water pressure at your faucets or a sputtering flow. You might also hear a hissing or running water sound in the walls or floors even when nothing is on.

Check your water meter for constant movement when all water is turned off. That often points to a leak somewhere in the supply line. If you notice damp spots on floors or a musty smell, the leak may have already reached your foundation. The sooner you locate it, the less damage it can cause.

Prevention starts with knowing what's underground. Have a professional map your water line locations before you do any digging or landscaping. This reduces the risk of accidentally damaging a pipe.

Consider replacing old metal pipes with modern materials like PEX or copper, which are more resistant to corrosion and root intrusion. Also, maintain a consistent watering schedule for your lawn to minimize soil shifting. If you live in Kirkland, keep a written record of your shutoff valve location and check it regularly for easy access.

Remember that the mild marine climate with wet winters and dry summers can cause the ground to expand and contract, so be mindful of how that affects your lines.

• Know your pipe locations before digging
• Replace corroded pipes with durable materials
• Water your lawn evenly to reduce soil movement
• Monitor your water bill for sudden changes
• Keep your shutoff valve accessible and tested