Rusty water in a 4 yro home

Any ideas what could be causing rusty water? Main line copper, distribution lines CPVC, water heater 2013. Seems to be on cold water side.

Did the Water District just flush the hydrants:)

Don’t know, but there was some construction going on about 1/2 mile away. More town homes being built.

Is the water supply municipal or well water.
Could be if the home has been vacant for a while the water heater may need to be flushed.
Or if on a well the cu line can get corroded from a low pH reading.