Johnson Lake’s turquoise colored waters is due to the presence of limestone, the color of the lake’s water is like looking at the waters of the Caribbean.
Below Photo: A picture of Johnson Lake taken by my daughter.
Also there are a lot of images on Google showing the color and how clear the lake water is. You can find them at: Images Of The Lake.
If you have a picture you would like to share on this page from around Houston, please contact me at firstname.lastname@example.org