(excerpt from Eat Less Water chapter Wheat and Water)
December 31, 2011
I followed the rain clouds along the two-lane road leading to With the Grain farm. On a slope above the wheat fields was a small house, home to John DeRosier, his wife Leaf and teenage son Noah. Near the house stood a barn stripped of paint from decades of sun and rain. It was charming. John’s big dog, his only companion on most days, joined us.
Among the gentle slopes of Paso Robles, John’s farm is an anomaly. Lines of grapevines squeeze his farm from every direction. Neighboring vineyards rely on continuous sips from wells that act like big straws, slurping up water from the aquifer for irrigation. John’s well, dug 300 feet deep, maintains the same level as when it was drilled six decades earlier. Surrounding vineyards are drilling 1,000 feet beneath the surface to find water. Wells are being drilled deeper and deeper, a sign that water is being extracted faster than it is replenished.
The summers reach 110 degrees Fahrenheit. Rain was imminent on the spring day I visited, but this part of the valley receives an average of only six inches of water a year, mostly in the winter months. This is less rainfall than the desert city of Phoenix, Arizona. Rain-fed crops need annual rainfall of ten inches or more; and less, and ordinarily the wheat farmer must irrigate. A common choice is flood irrigation that turns rows of wheat into straight, shallow rivers. It’s the cheapest method of irrigation (as long as the price of water remains low), but it has the highest rate of water loss through runoff and evaporation.
“You don’t irrigate your crops even in the dry months?” I asked John.