Water leaks are one of the most damaging—and most commonly overlooked—plumbing problems homeowners face. A small drip under a sink or a pinhole leak behind a wall might seem minor, but over days, weeks, and months, even the smallest water leak can lead to structural damage, mold growth, and hundreds of dollars in wasted water.
In Upland, where homes range from decades-old builds near downtown to newer construction in the foothills, water leaks can take many forms. Knowing how to spot the warning signs early can save you thousands and protect your home’s value.
The Most Common Types of Water Leaks in Upland Homes
Sink Leaks: The most visible type of leak often occurs under kitchen or bathroom sinks. Loose connections, worn-out washers, or cracked supply lines can cause water to pool inside your cabinet. Left unaddressed, sink leaks lead to warped cabinetry, mold growth, and water damage to floors.
Slab Leaks: Upland’s soil composition and occasional ground shifting can put pressure on the water lines running beneath your home’s foundation. Slab leaks are especially dangerous because they’re hidden—you may not notice them until you see unexplained wet spots on your floor or a spike in your water bill.

Pipe Leaks Behind Walls: Aging galvanized pipes, joint corrosion, and high water pressure can cause leaks inside your walls. Warning signs include discolored paint, bubbling wallpaper, musty odors, or the sound of running water when no fixtures are in use.
Toilet Leaks: A running toilet or a leak at the base can waste hundreds of gallons of water each month. If you hear your toilet refilling when nobody has flushed, or if you see water around the base, you likely have a toilet leak that needs professional attention.
7 Warning Signs of a Water Leak
- Unexplained Increase in Your Water Bill: If your usage habits haven’t changed but your bill has climbed steadily, a hidden water leak is a likely cause.
- Musty or Moldy Odors: Persistent dampness from leaks creates the perfect environment for mold. If you smell mildew in certain rooms, investigate further.
- Discoloration on Walls or Ceilings: Yellow or brown water stains on ceilings and walls are a telltale sign of a leak in the pipes above or behind them.
- Warped or Buckling Flooring: Water seeping under hardwood, laminate, or tile can cause floors to warp, buckle, or feel soft underfoot.
- Sound of Running Water: If you hear water flowing when all fixtures and appliances are off, there may be a leak somewhere in your supply lines.
- Low Water Pressure: A sudden drop in water pressure across your home can indicate a significant pipe leak diverting water before it reaches your fixtures.
- Wet Spots in the Yard: Unexplained puddles or unusually green patches of grass in your yard may indicate an underground leak in your main water line.
What to Do When You Find a Water Leak
If you discover a water leak in your Upland home, act quickly to minimize the damage. First, turn off the water supply to the affected fixture or, if the leak is severe, shut off the main water valve to your entire home. Next, move furniture and belongings away from the affected area to prevent further damage. Then, call a licensed plumber immediately.
Plumber Upland’s team uses advanced electronic leak detection equipment to locate hidden leaks without tearing apart your walls or floors. Once we pinpoint the source, we’ll explain your repair options, provide an upfront price, and get the job done right—often the same day you call.
Preventing Water Leaks in Your Upland Home
The best way to deal with water leaks is to prevent them from happening in the first place. Schedule an annual plumbing inspection to check for wear and corrosion in your pipes, fixtures, and supply lines. Monitor your water bill for unexplained increases. Install water leak detectors near water heaters, washing machines, and under sinks for early warning. And if your home has older galvanized or polybutylene pipes, consider a proactive repipe before a failure occurs.