Surface water

As the climate warms in the spring, snowmelt runs off towards nearby streams and rivers contributing towards a large portion of human drinking water.

[1] For USGS water-use reports, surface water is considered freshwater when it contains less than 1,000 milligrams per liter (mg/L) of dissolved solids.

Permanent (perennial) surface waters are present year round, and includes lakes, rivers and wetlands (marshes and swamps).

This includes the amount of rain and snowmelt drainage left after the uptake of nature, evaporation from land, and transpiration from vegetation.

In areas such as California, the California Water Science Center records the flow of surface water and annual runoff by utilizing a network of approximately 500 stream gages collecting real time data from all across the state.

The quality of surface water is based on the chemical inputs from the surrounding elements such as the air and the nearby landscape.

However, there is an ever-increasing need for management of the two as they are part of an interrelated system that is paramount when the demand for water exceeds the available supply (Fetter 464).

Depletion of surface and ground water sources for public consumption (including industrial, commercial, and residential) is caused by over-pumping.

An inland lake, an example of surface water
The entire surface water flow of the Alapaha River near Jennings, Florida going into a sinkhole leading to the Floridan Aquifer groundwater .
A stream gauge used to measure surface water.