That weak trickle in the shower isn't your imagination
If you're standing in a shower in an older part of Nixa wondering why the water pressure has dropped to a dribble, especially on the second floor, you're probably not dealing with a well pump issue or a city water problem. You're dealing with pipe. Specifically, galvanized steel pipe that has been quietly narrowing itself from the inside for forty or fifty years.
This shows up gradually, which is why people miss it. A few years ago the shower was fine. Now you can't run the dishwasher and take a shower at the same time without one of them losing pressure entirely. That's not coincidence. That's the pipe finally catching up to itself.
Why Nixa's housing stock runs into this so often
A lot of homes in and around Nixa, especially in the older parts of town and out toward Christian County's original county roads, were built in the 1950s through the 1970s, before copper and PEX became standard. Galvanized steel was the normal choice back then. It was cheap, it was strong, and nobody was thinking about what the inside of that pipe would look like decades later.
Galvanized pipe is steel with a zinc coating on the inside meant to prevent rust. That coating doesn't last forever. Once it breaks down, usually somewhere around the 40 to 50 year mark, the bare steel underneath starts corroding and building up mineral scale. The pipe's outer diameter stays the same, but the usable inside shrinks, sometimes down to a fraction of what it was. It's the plumbing equivalent of a clogged artery.
More on this from Reading List Old Galvanized Line And The Pressure It Costs.
What the Ozarks water and seasons do to it
This part of Missouri has fairly hard water, and hard water accelerates the mineral buildup inside galvanized pipe. It's not the only cause of corrosion, but it speeds up a process that was already going to happen.
Then there's the freeze-thaw cycle. Nixa doesn't get brutal winters like farther north, but it gets enough hard freezes, followed by warm spells, followed by more freezes, that pipes expand and contract more than people realize. In a newer copper or PEX system that flexibility is built in. In old galvanized pipe that's already thinned and brittle from corrosion, that seasonal movement is what turns a slow leak into a pinhole, usually right at a joint or an elbow where the pipe was already weakest.
What you can actually check yourself
Start by looking at exposed pipe in the basement, crawlspace, or utility area. Galvanized pipe looks dull gray and has visible threaded joints. If you see rust colored water stains anywhere along it, or a white or orange crust building up around a joint, that's corrosion working from the inside out and showing itself on the outside.
Run a simple pressure comparison. Turn on a full bathtub tap by itself and time how long it takes to fill. Then try it again while running the kitchen sink at the same time. A big drop tells you the supply line feeding that part of the house is restricted. Also check water color first thing in the morning, before anyone else has run water. Rusty or brownish water after the pipes have sat overnight is a strong sign of internal corrosion, especially if it clears up after running for a minute.
None of this requires tools beyond a phone timer and your own eyes. It just requires actually looking, which most people don't do until the pressure problem gets bad enough to complain about.
Where this stops being a DIY project
Galvanized pipe repair is not a patch job in the way a PVC leak might be. Once corrosion has narrowed the inside of the pipe, cutting out one bad section and threading in a new fitting doesn't fix the pressure problem, because the rest of the line is still narrowed the same way. It buys a little time at best.
If you're finding rust stains, seeing consistent pressure loss on lines you know are galvanized, or dealing with recurring pinhole leaks, that's the point to call a plumber rather than keep patching. A professional can run a real assessment, sometimes cutting into a section of pipe to look at the actual internal diameter, and tell you whether you're looking at a section replacement or whether it makes more sense to replumb the affected runs with copper or PEX. For a lot of Nixa homes from that era, once one section is failing, others of the same age and material aren't far behind.