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The Myth of Efficiency

Many irrigators face the public perception that flood irrigation systems are inefficient and a waste of water. But water does far more than just grow food for humans.

In flood irrigation, an ancient system used by many indigenous cultures, gravity-fed ditch systems carry water to farm fields and pastures. Irrigators use tarps, mud plugs, smaller ditches and siphons to spread the water across the land. Water that is not consumed by plants either soaks into the soil and, in many cases, returns to the aquifer, or runs off back into the stream. Modern irrigation systems such as drip lines and pivots can direct and meter water out more precisely onto targeted plants. However, this can also increase crop production and therefore the consumptive use of water, leaving less to recharge aquifers and streams and to support wildlife. 

“I believe flood irrigation is important along the river because it recharges the shallow aquifers and it runs back into the river,” New Mexico farmer and acequia association president Ralph Vigil said. “People from urban areas don’t understand that. They think we need to modernize. They think we need more infrastructure. I do both. I flood irrigate when the water is available and use drip irrigation when there is less water. Acequias have created lush, fertile places, greenbelts in these traditional communities. I started noticing the wildlife, the bald eagles that are associated with the microclimates these acequias create. If we sell these out, they will be gone forever.” 

Wyoming rancher Pat O’Toole echoed Vigil’s perspective. “I have a saying called the myth of efficiency,” he said.  “On our ranch we are a third pivot and side roll and two thirds flood. We do not want to change that mixture. Putting that water on the ground with the flood irrigation does multiple things. The reason that there are no migratory birds on the potential endangered species list is because of the work farmers are doing with flood irrigation. It is also recharging our aquifers. I think these flood irrigation systems are the reason we still have landscapes.”

A recently published brief from the Intermountain West Joint Venture (“Digging Deeper into Flood Irrigation”) provides additional information about the importance of flood irrigation to agriculture and wildlife. ​Find that brief here: onland.link/flood-irrigation.


Learn more about Ralph Vigil’s and Pat O’Toole’s perspectives on drought and water management in A Long Dry Time.