The larger, silty sediments then begin settling to the bottom of the river, leaving only the finer ones suspended in the water. This is the sweet spot where you get the teal/turquoise color.

Water looks turquoise due to a combination of light scattering, water depth, and seabed composition. Pure water naturally absorbs red and orange light (long wavelengths) and reflects blue light (short wavelengths). When water is shallow and the bottom is covered in white, sandy sediment (often made of calcium carbonate), the blue light reflects off the white floor and travels back up through the water. This shorter path prevents the light from turning a deep navy, resulting in a vibrant turquoise or teal color. Additionally, "glacial flour" (fine rock particles) in alpine lakes or certain types of phytoplankton in the ocean can scatter light in a way that emphasizes green and blue hues. In 2026, environmental scientists also note that "turquoise" water can be a sign of high mineral content or specific healthy coral ecosystems that reflect light differently than murky, sediment-heavy coastlines.