The World's Water Supply at Risk?

Posted by Robert Dailey Aug 8, 2006

"Water, water, every where,

Nor any drop to drink.

-Samuel Taylor Coleridge, The Rime of The Ancient Mariner

Of all the water on the planet, only 2.5 percent of it is fresh water. And 70 percent of that is frozen in the polar ice caps. The remaining 30 percent (of the 2.5 percent) is present as moisture in the soil or in underground reservoirs.

So how much water is readily accessible to humans for direct use? Only about .007 percent of all the water on earth.

As world population grows, the demand for usable water also increases. In the United States alone the demand is quickly approaching the supply.

In the states of Nevada and Utah, two of the driest states, human consumption is currently between 269 and 325 gallons per day, per person. Consumption ranges between 225 and 268 gallons per person per day in New Mexico, Wyoming, Idaho, Washington, Oregon and Alabama. Other states using in excess of 200 gallons per person per day include Hawaii, Colorado, Montana, Nebraska, South Carolina and West Virginia.

Approximately 37 million people live in those states. Averaging 200 gallons of water per day per person, that's almost 7.5 billion gallons of water per day being used by these states alone.

There are already water shortages being experienced in the U.S. The Colorado River (the major river west of the Rocky Mountains) rarely makes it to the Gulf of California. The Rio Grande, one of the major rivers east of the Continental Divide, rarely makes it to the Gulf of Mexico.

These are small examples of what's happening globally. The Yellow (Yalu) River in China first ran dry in 1972. It has run dry every year since 1985. In 1997, the river failed to reach the sea for almost six months.

In India, there is little if any water left as the Ganges streambed reaches the Bay of Bengal. In Northern Africa, the same is true of the Nile.

Back in the U.S., one of the largest aquifers in the country, the Ogallala Aquifer, is dropping significantly.

Texas, Oklahoma, Kansas and Colorado have been losing the potential to irrigate land for the last two decades. Texas in particular has been losing one percent per year since 1980.

In China, the water tables are dropping around five feet per year.

In fact, water tables are falling on every continent. In addition to increased immediate water needs for humans as the population increases, there is also an increase in the need for water to irrigate food crops, particularly grain. As a result, large diesel and electrical pumps are sucking even more water from aquifers, rivers and lakes.

It takes about 1,000 tons of water to grow one ton of grain. Current world grain exports are now at 200 million tons of grain. The current world water deficit is around 160 million tons. Do the math.

Now, countries in Africa, the Middle East, India, Nepal, and Latin America are using methods of growing food crops that significantly conserve water and increases yield. These farming methods have been used in large-scale agricultural operations to tiny garden plots.