Front yard, stop 5 of 5

Low water pressure: one tap or the whole house?

Low water pressure at one sink or shower often starts with an aerator you can remove and rinse; a drop across the whole house could be a leak or a main break, so contact your water utility.¹

Go to the kitchen sink first, then each bathroom, then an outdoor tap, opening each one as you pass.

Updated November 4, 2026, Midlands House Walk

Brass ball valve with a red lever on copper pipe entering a red brick foundation above mulch — Check your own valve early. A house shutoff left partly closed after a repair can choke every tap. AI-generated picture.

Brass tap on red brick with a green garden hose coiled on pine straw below it — An outdoor tap makes a good second opinion. Take the hose off and compare its flow with the kitchen’s. AI-generated picture.

Is it one tap or every tap?

Look for: Run the kitchen cold, then a bath, then an outdoor tap with the hose off. Note which are weak, and whether it’s hot, cold or both.
What it tells you: One weak tap points at that tap, and Columbia’s advice is to remove and rinse the aerator.¹ Weak hot with strong cold is worth telling a plumber. Every tap weak sends you to the next checks.

Round-dialed brass meter in an open in-ground box with damp soil around it — With every tap closed, this dial should hold still. If it’s moving during a pressure drop, suspect a leak. AI-generated picture.

Could a leak be taking the pressure?

Look for: Close every tap and look at the dial, or run the two-hour meter test.²
What it tells you: Movement with everything off points to your side of the meter. A still dial and weak taps all over may point to the utility, so ask it about a main break, or to old narrowed pipe.¹

Hand holding a cut length of old galvanized pipe with rust caked inside the open end — Rust caked inside a cut length of old galvanized pipe. Scale like that can narrow the flow over years.

Did it fade slowly over the years?

Look for: Check any pipe you can see, at the water heater or from the hatch, for dull gray threaded metal. Galvanized pipe is iron or steel dipped in zinc.³
What it tells you: A slow fade in an older house can mean narrowing pipe. That calls for a plumber’s eye, and the galvanized stop lists what to ask.

Water service line with several brass valves running down a white plastic-covered wall — Brass valves on a service line. If one on your line has a bell-shaped body, ask whether it’s a pressure regulator.

Does your house have a pressure-reducing valve?

Look for: Some houses have a bell-shaped brass valve near where the line comes in. Plenty of houses have none.
What it tells you: If there is one and it’s worn, pressure can sag or swing. A plumber can put a gauge on the line and say. Leave its adjusting screw for them.

Lexington water tower with the utility's name on the tank, seen across an intersection with signals — The Joint Municipal Water and Sewer Commission tower in Lexington. The name on your bill says who holds the answer on pressure.

What pressure should the utility deliver?

Look for: Columbia gives a range of 40 to 120 psi.¹ Read your bill to see whose water you have.
What it tells you: West Columbia, Cayce, the Town of Lexington and the Joint Commission are separate providers,⁴ so ask yours for its own figure rather than borrowing Columbia’s.

Did the neighbors lose pressure too?

If they did, the trouble is likelier in the street than in your walls. Loss of pressure in a significant part of the system is one of the reasons Columbia issues a boil water advisory,⁵ so check the utility’s alert page before you drink or cook.

Yours to do

Remove and rinse the aerator on the weak tap.¹
Check your house shutoff is fully open.
Write down which taps are weak and when it happens.

For a licensed pro

A whole-house drop goes to the utility first.¹
Gauge readings, regulators and narrowed old pipe go to a licensed plumber.

Where this comes from

Keep walking to side of the house (AI picture)Outdoor tap dripping or leaking at the wall