More Info on the Ogallala Aquifer in the Great Plains
Even though we know the dangers of heavily pumping water from aquifers, some regions are still dealing with these consequences. In the U.S. Great Plains, the Ogallala Aquifer is a prime example of groundwater depletion. This aquifer provides water for South Dakota, Nebraska, Colorado, Wyoming, Kansas, Oklahoma, Texas, and New Mexico. It spans an area of 800 miles from north to south, and 400 hundred miles from east to west.
Water level changes in the Ogallala Aquifer (Cunningham, William P. et. al., “Environmental Science, 7th edition, McGraw Hill 2003.)
It was first tapped in 1911 when a farmer dug a well by hand for irrigation purposes. In the 1950s there were approximately 80 wells a year that were being dug to tap the aquifer in Colorado alone. There were some restrictions placed on digging wells to tap the Ogallala Aquifer, but these limitations did not stop farms and cities from depleting the aquifer. This aquifer supplies 70% of the water used daily in Kansas.
The water pumped from Ogallala Aquifer is used mostly for irrigation purposes. The land in the Great Plains is semi-arid and the water that is available evaporates quickly. Due to the need for greater amounts of water for irrigation, the aquifer is being depleted because the recharging process cannot keep up with the withdrawal of water. Since people had started to rely on the Ogallala Aquifer for irrigation of their fields, 6% of the aquifer has dropped to an unusable level that can no longer be pumped. If irrigation continues to draw water from the aquifer at the same rate, about 6% of the aquifer will be used up every 25 years. One estimate states that the aquifer is being depleted at a rate of approximately 12 billion cubic meters per year. The biggest problem facing people who use the Ogallala Aquifer is that they do not know how long the water supply will last.