Monsoon season is the one time of year when Valley plumbing gets tested from the outside in. Months of dry, baked ground meet several inches of rain in an afternoon, and the ground itself moves. Most of the calls we take in July and August trace back to that swing rather than to anything that happened inside the house.
The National Weather Service office in Phoenix runs the season from mid June through the end of September, which gives you a clear window to prepare in. A short checklist before the storms start saves a great deal of trouble.
Why monsoon season is hard on plumbing here
Expansive clay soil sits under a large share of East Valley properties. Dry soil shrinks and pulls away from buried pipe. Then heavy rain saturates it within hours and it swells back. Buried sewer laterals, water lines and slab plumbing get dragged through that cycle twice a year, every year.
On top of that, storm runoff pushes silt, gravel and debris into yard drains and outdoor cleanouts that have sat dry and open for months.
Before the storms: five things worth doing
1. Clear yard drains and cleanouts
Lift the caps, clear the leaves and grit, and check the caps are intact and properly seated. A missing cleanout cap is an open invitation for debris to wash straight into your sewer lateral, and that is a blockage you pay to remove.
2. Test your main shutoff valve
Turn it fully off and back on again. Valves that have not moved in years seize, and discovering that during an emergency is the worst possible timing. While you are there, make sure everyone in the house knows where it is.
3. Check outdoor faucets and hose bibs
Arizona sun degrades the washers and seals in hose bibs faster than most people expect. A slow drip outside is easy to ignore for months, and it undermines the soil right next to the foundation, which is precisely where you least want saturated ground. If yours drips or the handle feels loose, our faucet repair service covers outdoor spigots and frost free bibs.
4. Have the sewer line inspected if it has a history
If your line has clogged before, or the home is older with mature trees nearby, a camera inspection before monsoon season is cheap insurance. Ground movement widens joints that roots have already found, which is exactly why older Mesa sewer lines fail in the first place.
5. Know where the water goes
Walk the property and look at the grading. Water should run away from the foundation, not pool against it. Saturated soil right at the slab edge is what turns ordinary seasonal movement into a slab leak. Check that downspouts and scuppers discharge well clear of the house.
During and after a storm: what to watch for
- Multiple drains slowing at once. Debris or root movement in the main line, not a local clog.
- Gurgling toilets. Air being displaced in a partially blocked line.
- Sewage odour outdoors. Usually a cracked lateral or a dislodged cleanout cap.
- A new damp patch that stays damp. Once the surrounding ground has dried, a spot that stays wet is far more likely a leak than leftover rain.
- Water pressure changes. A drop across the whole house after a storm can mean a shifted or cracked supply line.
- Discoloured water. Brief sediment after heavy rain is usually harmless, but water that stays cloudy for days is worth reporting to the City of Mesa water and wastewater department.
The one that hides the longest
Slab leaks caused by soil movement rarely announce themselves during the storm. They surface weeks later as a water bill that climbed for no reason, a warm patch on the tile, or carpet that will not dry out. It is worth knowing the six signs of a slab leak before that happens, and if any of them follow a heavy monsoon our leak detection service confirms the exact location before anything gets opened up. Where the copper has already failed, slab leak repair is usually a targeted spot repair rather than a full excavation.
Storm season is also drain season
Debris washed into a lateral does not clear itself. If several fixtures slow down in the week after a storm, that is a main line problem and drain cleaning and hydro jetting is normally the fastest route back to normal. Our comparison of snaking versus jetting explains which method suits which blockage.
If something does go wrong mid storm
Shut the water off at the main, cut power to any outlet near standing water, and stop using drains entirely if sewage is backing up. Our full emergency plumbing checklist covers the order to do it in.
Then call. Our emergency plumber team runs through monsoon season the same as any other night, and we cover Gilbert, Chandler, Tempe and Queen Creek alongside Mesa.
Hard water damage builds year round as well, quite separately from the weather. See what Mesa water does to fixtures, or browse our full range of plumbing services in Mesa AZ.