What Causes Streams & Rivers?

Precipitation

• The most common source of water that coalesces into rivulets, streams, creeks and eventually mighty rivers is from precipitation. When rain falls, some of the rain runs off to start the cycle. In cold climates, precipitation falls during the winter as snow. Come spring, the snow melts and the meltwater flows downhill to fill running streams and rivers.

Springs

• In many areas, the natural geography and topography team up to produce springs, a place where water naturally bubbles out of the earth. Where the natural flow is sufficient and continuous, the water from the spring, following the inviolate law that water will flow downhill, becomes the source of a flowing stream.

Ground Water

• In areas with a substantial layer of soil over the underlying bedrock, some of the water that comes from rain or snow percolates into the soil ever downward until it reaches a permanently saturated layer called the water table. Dig a narrow hole below the water table and you make a well. Make a large excavation below the water table and a pond or lake forms. In areas where the natural topography of the land is lower than the water table, water will ooze from the soil and form into flowing streams.

Man-Made

• For thousands of years men have dug trenches large and small to form ditches, canals and aqueducts to allow water to flow downhill. These man-made streams and rivers are used to move water from where it's not wanted or to areas where it is needed. Man-made streams are used to provide water for drainage, flood control, hydroelectric power, irrigation, drinking water and transportation.