Only 3 percent of the Earth ’ s water is freshwater , and about two-thirds of this water is frozen in polar icecaps and glaciers . Most of the remaining freshwater is underground and only 0.3 percent is surface water .
Let ’ s Examine The Water Cycle
Only 3 percent of the Earth ’ s water is freshwater , and about two-thirds of this water is frozen in polar icecaps and glaciers . Most of the remaining freshwater is underground and only 0.3 percent is surface water .
We need the water cycle , but it ’ s not what you might think .
There ’ s pretty much the same amount of water in the world now as there was when the dinosaurs were running around doing their thing . It keeps getting recycled . Water doesn ’ t get used up or destroyed , but it can get polluted .
The sun warms up the oceans , lakes and rivers , causing the water to evaporate . That evaporation condenses and makes clouds . Those clouds drop rain or snow on the earth . Some of that rain and melted snow soaks into the ground , but some runs off , making rivers , which eventually flow back into the sea . Even the water that soaks into the ground moves through the spaces in the sand , gravel and rocks .
How cool is that ? The water went from liquid , to vapor ( remember that evaporation part ), to solid ( ice and snow ), and back to liquid with the power of the sun .
Something else interesting happened . When it evaporated , it left the salt and other stuff behind so those snowflakes and rain drops are pretty clean . Air pollution sometimes messes up a good thing , but that ’ s another story .
Colorado plays a very important part in the water cycle .
In Colorado , most of the water we use comes to the state as snow in the mountains . In the spring , it melts and some is stored in lakes and reservoirs so that we can use it throughout the year .
Known as the “ headwaters state ,” Colorado is the beginning of eight major rivers that flow to other states . In an average year , the outflow of the Colorado River alone is equal to the amount of the water used annually by more than 9 million households .
In other words , the snowballs you threw during the winter could melt and end up as drinking water in Los Angeles , California or El Paso , Texas .
Eighteen states and Mexico get water that starts its journey in Colorado . Virtually no water flows into Colorado .
That also means there are tens of millions of people downstream from us who are counting on us to help protect that water as it moves through our state — one more reason to be a Watershed Defender .
But what happens if it only snows half as much as usual ? Or what happens if the reservoirs get polluted ?
That ’ s scary . Prolonged times of reduced rain and snow are called a drought . Reservoirs help us make it through dry times , but in a drought there isn ’ t enough water to meet all the needs . Farmers are often the first to experience problems .
With less rain , farmers need to use more irrigation water from rivers to help plants grow . If there ’ s not enough irrigation water , farmers are forced to plant fewer crops , plant less “ thirsty ” crops or even skip planting altogether . Fewer crops mean less food .
Even when there ’ s plenty of rain and snow , we have to be careful with our water . In Colorado , there is a demand for more water than there is supply . One reason is that population is growing . In 1850 , Colorado was a frontier in the western expansion of the United States . The world population was 1.2 billion people . Fast forward to the year 2000 and Colorado had a population of 4.3 million people , while the world population had jumped to more than 6.1 billion people .
More people means a greater demand for food and water .
We ’ ve been stuffing a bunch of big ideas and big numbers in our gear bag , but we need one more . The earth is a big place , and it ’ s sometimes called the “ blue ” planet . Why ? The earth is mostly covered in water .
Here we go with the bad news again .
The oceans are salty , too salty for humans to drink and a big bunch of
6 Watershed Defenders produced by Colorado Foundation for Agriculture