If the volume of water is restricted at the fixture, the most common cause is old pipes getting rusty and closing up. Iron oxide (rust) is formed inside the pipes when oxygen from the water combines with the iron of the metallic pipe. Iron oxide over time slowly decreases the inside diameter of the iron pipe and decreases the pipes wall thickness. Sooner or later (usually later) the pipe simply can not supply as much water as it used to. Remedy: Replace the pipes.
2. Rusty water:
Rusty water is more of an irritant and frustration than a health hazard. The iron oxide (rust) is not hazardous to your health. In fact we need some iron in our bodies but drinking rusty water is probably not the best way to get your daily minimum requirement of iron. Rusty water coming out of your kitchen faucet is not appetizing or aesthetically pleasing. Rusty water in your plumbing fixtures can stain them with ugly brown stains (use vinegar or citric acid to remove the stains). The best way to deal with rusty water is Remedy: Replace the pipes.
Old steel pipes will spring leaks when the pipe wall has been eaten away over time to the point that pinholes appear. A brown or discolored whitish stain on your old galvanized steel pipes mean that a leak is ready to happen. Spots on thepipes mean the iron is worn out and only the galvanized coating is holding the water back. If you have small spots and/or damp spots you have an emergency about to happen! Remedy: Replace the pipes.
4. Resale value:
Houses with copper piping are more desirable to buy than houses with old galvanized steel water pipes.