Natural water is never really clear; sediment and tannin cause color.

Natural water will never be totally clear, but will have some amount of color

Most of the color in water you see around you comes from suspended material, as you can see in the right-side picture of a tributary contributing highly-turbid water containing suspended sediment (fine particles of clay, since this picture is in Georgia) to clearer, but still colored, water in the main stem of the river. Algae and suspended sediment particles are very common particulate matter that cause natural waters to become colored. Even though the muddy water below would not be appealing to swim in, in a way that water has less color than the water containing dissolved tannins. That is because suspended matter can be filtered out of even very dirty-looking water. If the water is put into a glass and left to settle for a number of days, most of the material will settle to the bottom (this method is used in sewage-treatment facilities) and the water will become clearer and have less color. So, if an industry wanted needed some color-free water for an industrial process, they would probably rather start with the sediment-laden water, rather than the tannin colored water.