Will we deplete water supplies by growing ethanol?

Articles
May 12, 2009

Will we deplete water supplies by growing ethanol?

Will we deplete water resources if farmers grow vast amounts of corn for the production of ethanol? Opponents of the corn-for-energy practice raise the question, and there’s some science behind it. A typical corn plant consumes 4.2 gallons of water to make one gallon of ethanol, states the Institute for Agriculture Trade and Policy. Despite this, many farmers feel motivated to sell their crops to ethanol factories that pay higher premiums, rather than to food producers. The water problem is compounded by attempts to grow corn in areas less suitable for growth. This requires more irrigation, “which is rapidly depleting groundwater supplies,” reported Storm Exchange. “In areas where rainfall is significantly below normal, a water crisis may develop not only in the months ahead, but in the coming years and decades.” Farmers in western Iowa and eastern Nebraska are in just such a vulnerable area. Their precipitation has lagged between 20% and 60% of normal over the past 90 days—in “stark contrast to areas further east that have received copious amounts of rain and snow since the start of last winter,” the service noted.

Will we deplete water resources if farmers grow vast amounts of corn for the production of ethanol? Opponents of the corn-for-energy practice raise the question, and there’s some science behind it.

A typical corn plant consumes 4.2 gallons of water to make one gallon of ethanol, states the Institute for Agriculture Trade and Policy. Despite this, many farmers feel motivated to sell their crops to ethanol factories that pay higher premiums, rather than to food producers.

The water problem is compounded by attempts to grow corn in areas less suitable for growth. This requires more irrigation, “which is rapidly depleting groundwater supplies,” reported Storm Exchange. “In areas where rainfall is significantly below normal, a water crisis may develop not only in the months ahead, but in the coming years and decades.”

Farmers in western Iowa and eastern Nebraska are in just such a vulnerable area. Their precipitation has lagged between 20% and 60% of normal over the past 90 days—in “stark contrast to areas further east that have received copious amounts of rain and snow since the start of last winter,” the service noted.

Because of the threat to water supplies (from growing the corn and processing the fuel), several groups have recently petitioned President Obama to not increase the amount of ethanol blended into gasoline.

We already saw last year how elevated ethanol production played a role in higher food prices last year. The Congressional Budget Office said it drove up feed prices for cattle, hogs and poultry and accounted for 10%-15% of the rise in food prices in the 12 months ended April 2008.

Let’s be mindful of this, and develop ethanol policies that neither weaken our stewardship of the limited water resources Nature provides, nor unnecessarily stress our croplands or farmers.