The USGS Water Science School
This photo shows Silver Glen Springs in Florida, USA. Florida has large numbers of springs due to the large amount of porous limestone rock that makes up the ground below land surface. The spring pool at Silver Glen Springs is about 200 feet across. While it's only about 2 to 3 feet deep in many places, around the outflow hole the depth is about 18 feet.
Typical of springs, the water is very clear and free of dirt, mud, and other particles, unlike water flowing in rivers and in lakes. After all, the water filling up this spring comes from below ground, not from the land around the spring.
The crystal-clear water is a constant 73°F and the average discharge of water out of the ground is about 100 cubic feet per second, or almost 750 gallons per second.
Credit: Galina and Georgi Stanev