Low water pressure is one of the most frustrating plumbing problems a homeowner can deal with — and one of the most commonly misdiagnosed. Many people assume it's a city water supply issue and live with it for years, not realizing the cause is inside their own home and entirely fixable. In Lubbock, where our notoriously hard water accelerates mineral buildup inside pipes and fixtures, low water pressure is especially common. Here's how to figure out what's causing yours.
Step 1: Determine If It's One Fixture or the Whole House
The first question to answer is whether the low pressure affects every faucet and fixture in your home, or just one or two. This single piece of information narrows the diagnosis significantly.
Low pressure at one fixture only — The problem is almost certainly localized to that fixture. The most common cause is a clogged aerator (the small screen at the tip of the faucet) or a clogged showerhead. Both are easy DIY fixes: unscrew the aerator or showerhead, soak it in white vinegar for a few hours to dissolve mineral deposits, and reinstall. In Lubbock's hard water, this is needed every 1–2 years.
Low pressure throughout the house — This points to a problem with your main supply line, your pressure regulator, a partially closed shutoff valve, or a leak somewhere in the system. These require a plumber to diagnose properly.
Cause #1: Mineral Buildup Inside Pipes (Very Common in Lubbock)
Lubbock's water supply is among the hardest in Texas, with high concentrations of calcium and magnesium. Over years and decades, these minerals deposit on the interior walls of your pipes — a process called scaling — gradually narrowing the diameter of the pipe and restricting flow. This is especially common in galvanized steel pipes found in homes built before 1970.
Mineral scaling doesn't happen overnight — it builds up slowly over 10–20 years. By the time you notice a significant pressure drop, the pipes may be severely restricted. In extreme cases, a galvanized pipe that was originally 3/4 inch in diameter can be reduced to a pinhole opening by mineral deposits.
The fix: If scaling is widespread throughout the home, repiping with modern PEX or copper pipe is often the most cost-effective long-term solution. A whole-house water softener will prevent future scaling and protect your new pipes.
Cause #2: A Failing Pressure Regulator
Most homes in Lubbock have a pressure reducing valve (PRV) — a bell-shaped device typically located where the main water line enters the home, near the main shutoff valve. Its job is to reduce the city's supply pressure (which can be 80–150 PSI) down to a safe household level of 50–80 PSI.
When a PRV fails, it can cause one of two problems: it can fail open (causing dangerously high pressure that stresses your pipes and appliances) or fail closed (causing very low pressure throughout the house). PRVs typically last 10–15 years. If your home has low pressure throughout and the PRV hasn't been replaced in over a decade, it's a strong suspect.
The fix: PRV replacement is a job for a licensed plumber. The repair is straightforward and typically takes 1–2 hours. A new PRV will restore proper pressure immediately.
Cause #3: A Partially Closed Shutoff Valve
This is a surprisingly common cause of whole-house low pressure, and it's the easiest to fix. After any plumbing repair — or after a home purchase — the main shutoff valve or the meter valve may not have been fully reopened. Even a valve that's 80% open can cause a noticeable pressure drop.
Check both the main shutoff valve inside your home and the valve at the water meter. Both should be fully open. For a ball valve (lever handle), the handle should be parallel to the pipe. For a gate valve (round wheel handle), turn it counterclockwise until it stops. If you're not sure where these valves are, a plumber can locate and check them during a service call.
Cause #4: A Hidden Leak
A significant leak anywhere in your supply system — behind a wall, under the slab, or in the yard between the meter and your home — will reduce pressure throughout the house. The water that should be reaching your fixtures is instead escaping through the leak.
To check for a hidden leak, turn off all water in the house (including the ice maker and any appliances) and watch your water meter. If the meter is still moving, water is flowing somewhere it shouldn't be. This is a strong indicator of a leak that requires professional leak detection.
In Lubbock specifically: Slab leaks are a significant concern due to our clay-heavy soil, which shifts with moisture changes and puts stress on pipes beneath the foundation. If you have low pressure combined with warm spots on the floor, unusually high water bills, or the sound of running water when everything is off, call Cotton City Plumbing immediately for a slab leak inspection.
Cause #5: City Supply Issues
If your neighbors are also experiencing low pressure at the same time, the issue may be with the city's water main rather than your home's plumbing. This is most common during high-demand periods (summer mornings when everyone is watering their lawns) or when the city is doing maintenance work in your area.
Check the City of Lubbock's water utility website or call their customer service line to see if there are any reported outages or maintenance in your area. If the pressure issue is consistent and not related to city work, the cause is almost certainly within your home's plumbing.