If you were asking what the fresh water is called that flows across the surface of the land, then your answer would be:
Runoff is fresh water that flows along the surface of the ground. It originates from precipitation or melting snow and ends up in rivers, lakes, or oceans.
A river.
I assume you are asking "why" and not "what". Water, like all other matter on earth, is affected by the earths gravity. Gravity has pulled much of the surface water into large pools, we call oceans, that cover the lowest parts of the planet. Fresh water deposited on land by rain, sleet, snow, and hail will follow this same downward path towards the oceans.
So I guess the real answer to your question is gravity.
fresh flowing surface water is one of our most precious resources
Fresh water flows across Earth's surface in rivers, streams, lakes, and glaciers. It is essential for supporting ecosystems, agriculture, and human populations. The water cycle ensures that fresh water is continually replenished and distributed around the planet.
It is a fresh water stream.
A fresh surface of uranium is similar to the surface of a steel.
flowing water and standing water
River means a large natural stream of fresh water flowing along a definite course, usually into the sea, being fed by tributary streams.
Majority of rivers and streams have fresh water flowing in them.
Fresh rich oxygen to keep the circulatory flowing.
A "tributary".
It contains one-fifth of the worlds fresh surfacewateer!
River is fresh water that flows while a waterfall comes from a high place.
After my opinion the fresh surface of copper is not dull.