CHAPTER 11 - WATER Section 1 – Water Resources – Pt 1

Fresh Water Naturally occurring water on Earth’s surface having low concentrations of salt. 3% of Earth’s total water. Freshwater is a limited resource because humans can use it faster than the Water Cycle can replenish it.

Fresh Water Locations Frozen in Ice Caps / Glaciers 1.75 – 2% Groundwater % Lakes, Rivers, Swamps >0.01% Atmosphere 0.04%

Where Does our Water Come From? Two main sources of water 1. Surface water  Found on Earth’s surface 2. Groundwater / aquifers  Found under Earth’s surface

Surface Water Fresh water on Earth’s land surface. Rivers, Lakes, Streams Easily harvested for human use. Throughout history, major cities and settlements have been built next to surface water sources.

Collecting Fresh Water - Watersheds Watershed A large geological boundary that determines where water will collect and drain. All of the rainfall in a watershed will be directed to the same place.

Collecting Fresh Water - Watersheds Runoff water can collect in streams and then will create river systems. Almost all watersheds will eventually drain to the Ocean.

United States Watersheds