Generally flushing disturbs the water in the mains and causes small particles of rust or calcium buildup to dislodge and suspend in the water. This water will show up in your household as discolored water and have a yellow to orange to red color. This water, while unappetizing, poses no health threats. Running your faucets for several minutes will usually clear the household system and resolve all problems. Occasionally faucet aerators (screens) will have to be removed and cleaned to restore water pressure.
To find out more about the program, click here: https://www.villageofshorewood.org/1168/Hydrant-Flushing