Is It SAWS or Your House? Who Fixes Low Water Pressure in San Antonio
Published November 7, 2026 · San Antonio Water Pressure Pros
When the shower runs weak, the first question is not what is broken — it is whose job it is to fix it. In San Antonio, SAWS owns the water mains up to your meter. Everything past the meter is yours. Here is how to tell which side of that line your problem sits on, and what to do in each case.
Where SAWS Responsibility Ends
The line is the water meter. It usually sits in a green box in the lawn near the curb or sidewalk, where the main line from the street meets your property. SAWS — the San Antonio Water System — delivers water to that meter and maintains the mains in the street. Everything past the meter is on the homeowner's side: the customer shutoff valve, the pressure regulator (PRV), and all the pipe inside your property. SAWS's own guidance puts the PRV and the customer valve on the property owner's side of the meter.
That is why the same weak shower can be two different jobs. If the problem is in the main, SAWS fixes it. If it is past the meter, a plumber does. Knowing which side you are on saves you a wasted call in either direction — and it is the first thing we ask about when you call us.
One more thing the meter line explains: pressure varies a lot by street. SAWS says water pressure in its service area can range from 35 to 175 PSI, because pressure depends on elevation and distance from the mains. A house on high ground far from a main will read lower than a house downhill near one, and both can be normal for their street. SAWS recommends a maximum of 80 PSI, especially if you have a water softener or a sprinkler system.
Three Checks Before You Call Anyone
Run these three checks before you call SAWS or a plumber. They take a few minutes, and they usually settle the question.
- Ask your neighbours. If the houses around you have the same weak pressure, the cause is probably on the street side — SAWS work, a burst main, or high demand on the main. If yours is the only weak house on the street, the cause is inside your property.
- Whole house or one fixture? Check every faucet. If the whole house is weak, the cause is at the main line, the PRV, or the supply — the kind of problem that sits on one side of the meter or the other. If one fixture is weak and the rest are fine, the problem is at that fixture: a clogged aerator, a scaled showerhead, or a worn cartridge. See fixture low pressure repair.
- Look for work in the street — and at your own main valve. SAWS crews, a dug-up road, or a water main repair nearby are all street-side causes. Closer to home, check whether the pressure changed right after any work at your own main valve or meter. A valve left half open after a repair throttles the whole house, and it is a free fix once you find it.
How to Report a Main-Line Problem to SAWS
If your checks point to the street side, report it to SAWS at 210-704-SAWS (7297). Customer service takes calls from 8 a.m. to 5 p.m., Monday to Friday. Water and sewer emergencies use the same number, 24 hours a day, 7 days a week.
When you call, tell them four things: your address, when the pressure dropped, whether your neighbours have the same problem, and anything you can see — water pooling in the street, a leak near the curb, or work on the main. The more specific you are, the faster they can tell whether it is a main problem. If the problem turns out to be on your side of the meter, SAWS will tell you that too — and then it is a plumber's job, not theirs.
A practical note: after main work in your street, pressure sometimes stays low for a while even once the work is done, because sediment stirred up in the main can clog aerators and showerheads. If your pressure does not come back after the work ends, check and clean the aerators first — it is a five-minute job and it often fixes the last bit of the problem.
Signs the Problem Is Inside Your Home
These patterns point to your side of the meter:
- Only your house is affected. Your neighbours have normal pressure and yours does not. The cause is inside your property.
- Pressure has been falling slowly for months. A slow decline points to scale or old pipe narrowing from the inside. San Antonio water runs about 280 to 300 parts per million — very hard — and that hardness leaves scale in pipes year after year. SAWS itself puts typical hardness at 15 to 20 grains per gallon — about 257 to 342 parts per million. That is the unit SAWS publishes in, and it is why the water here counts as very hard: anything above about 180 parts per million is very hard on the USGS scale. See pipe descaling, or whole-house repiping when the pipe is too far gone to clean.
- Hot water only is weak. Cold water runs fine and hot water does not. The cause is usually sediment in the water heater or scale in the hot-water lines, not the supply.
- Pressure drops when two fixtures run at once. One fixture can run, but two cannot. That is a restriction in your pipes, not in the main.
- Banging pipes, or pressure that swings high and low. That points to the pressure regulator. See pressure regulator repair and replacement.
- Your water bill has risen along with the pressure drop. A higher bill can mean a hidden leak on your property, bleeding pressure away before it reaches your fixtures.
What a Plumber Checks First
If the checks above point to your side of the meter, a testing visit settles the rest. We put a gauge on the main where water enters the home and at fixtures around the house, and we compare the readings. A healthy main reading with weak fixtures means the restriction is inside. A low reading at the main with the street supply healthy points to the PRV or the main valve. We also check the regulator's behaviour — whether it holds a steady pressure or drifts — and we run a meter check for leaks: turn off all the water in the house and watch the meter dial. If the dial still moves, water is escaping somewhere on your property.
That is what water pressure testing and diagnosis is for. You get a plain explanation of what we found and a price before any work starts, and you decide whether to go ahead. If you want to check the numbers yourself first, our guide to testing your water pressure at home in 5 minutes walks through the gauge test step by step.
Call San Antonio Water Pressure Pros
Tell us what your water pressure is doing, and we will talk through what happens next and set a time to come to your home.
14570 Calaveras Creek, San Antonio, TX 78223
Frequently Asked Questions
Who fixes low water pressure on my street?
SAWS handles the water mains up to the meter. If the problem is on the street side — a burst main, maintenance, or low main pressure — report it to SAWS at 210-704-SAWS. If it is past the meter, it is the homeowner's job, and a plumber handles it.
My neighbours are fine. Is it my house?
Almost certainly. When the houses around you have normal pressure and yours does not, the cause is inside your property — the pressure regulator, the main valve, the pipes, or a leak.
SAWS is doing work on my street. Should I wait?
If the work is on the main and your pressure dropped when it started, wait until the work is finished. If pressure stays low after the work ends, clean the aerators first — sediment stirred up by main work can clog them.
What should I tell SAWS when I call?
Your address, when the pressure dropped, whether your neighbours have the same problem, and anything you can see — water pooling in the street, a leak near the curb, or work on the main. The more specific you are, the faster they can tell whether it is a main problem.