Water on the Surface 11 – 2A river and all of its tributaries make up a

river system

Water that remains on Earth’s surface is runoff. This water eventually makes its way to

creeks, streams and rivers.

The land area that supplies water to a river system is called a watershed or a drainage

basin.

The Chagrin River has many tributaries (little creeks and streams that flow into the main river)

Tributaries flow toward the main river following a downhill

path due to gravity.

Remember! GRAVITY causes water to flow.

• Lakes, river and streams all flow towards the ocean. This is called SEA LEVEL. All land areas are measured in distances above sea level. Solon, Ohio is 1040 feet above sea level.

• Water continues to flow toward sea level.

Water that seeps below Earth’s surface becomes groundwater.

Large pockets of groundwater are called aquifers.

Topography is the study of the shape of land; its elevation, relief and landforms.

As you know, elevation refers to feet above sea level.

Relief has to do with the highest and lowest parts of an area.

Notice water locations - Lakes and streams.

Which way does water flow?• That way! Again, water will flow in a

path of least resistance - always toward sea level.

Freshwater Pollution (12-3, page 411)

Water pollution can move through each level of the water cycle.

Cuyahoga River Catches Fire!

JUNE 22, 1969

Contamination = PollutionWater pollution is the addition of any substance that

has a negative impact on water or the life in it.Water pollution can happen in all spheres! That is air,

groundwater, lakes, rivers, streams or oceans.

Main sources of water pollution include: human wastes, industrial wastes,

agricultural chemicals and runoff from roads.

Pollution that can be traced to a source is called point source pollution.

Pollution that cannot be traced to a source is nonpoint source pollution.