The water that finally reaches the ground sinks into the soil and is evaporated or runs off slowly.

The portion that is absorbed by the soil is taken up by the roots of the trees and plants or goes to supply springs and watercourses.
The power of the trees and forest soil to absorb water regulates the rate at which the rainfall is fed to the streams and rivers.
Frequently it takes weeks and even months for all the waters of a certain rain to reach these streams.

This gradual supplying of water to the streams regulates their flow.

It prevents floods and freshets.

Careful observation and measurements have shown that unforested regions will discharge rain water at least twice as fast as will forested districts.
The stealing of soil by erosion occurs where run-off waters are not obstructed by forest growth.