Recharging underground water supplies through old and new channels and methods may only lead to overconsumption, especially if drought conditions return in a few years.
Several water management experts in the central and southern San Joaquin Valley, where painful drought conditions have prevailed for the past five years, are discussing additional channels and choices for putting some of this year’s excess water into underground storage for future use. And they’re considering continuing programs to bolster those pools every year.
But an associate professor at UC Davis and two students there have issued a caution. They have written an article about their concerns in the January-February issue of ARE Update, published by the Agriculture and Natural Resources Department of the University of California. It suggests that additional water demand and consumption, not all of it by farmers, may overdraw the underground water account, no matter how much can be deposited there.
Associate Professor Cynthia Lin Lawell, Ph.D., student Louis Sears and B.S. student David Lim suggest that groundwater conservation programs, though well-intentioned, might have “perverse” consequences. They warn that such programs might increase rather than decrease the amount of groundwater extracted.
The authors cite the experience of an intended water saving program conducted in Kansas in which growers were offered subsidies to improve their irrigation systems. The “perverse” result was that farmers used the improved systems to pump more water, increasing rather than decreasing dependence on underground supplies.At the same time, water management experts statewide continue studying and experimenting with processes and systems that will allow water from winter rains and spring snow melt to find its way to natural underground storage basins. If the level of those basins can be maintained at reasonable depths, pumping the water out is manageable, beneficial and reassuring
California Secretary of Food & Agriculture Karen Ross praised these efforts recently, saying they are occurring at the local level because people prefer that no actions or plans be imposed at the state level. She acknowledged the wide scope of studying groundwater because it overlaps “areas like land use and development for cities and counties.”
The Davis researchers point to the probability that incentives or subsidies offered to farmers for installing improved irrigation technology are likely to cause them to shift some dry land to irrigated acreage, resulting in pumping greater volumes of water – no saving of water there.
What the Davis report did not discuss is the demand of population increases on water supplies. California’s population has been growing since the gold rush, and is expected to reach 40 million soon. Domestic water supplies for the expanding population primarily come from underground sources.
To some extent the default in underground supplies is at least partly the result of improved irrigation technologies on farms. Drip irrigation conserves water, but its shallow distribution only to root zones prevents percolation back to the underground. Out of date flood irrigation, tabbed in many cases as wasteful, allowed deeper penetration of water applied to crop land, thereby a return to the underground pools.
While many Californians don’t seem to know or care where their water comes from, farmers do, and they want to preserve and protect, even improve access. The effort to do that is intense.
What the Davis report offers is a caution to the many agencies and individuals attempting to protect and increase the great groundwater basins beneath some of California’s most productive agricultural land. While well intended, their end result can be perverse, and if there’s anything California doesn’t need it’s more perversions.
Don Curlee is an agriculture consultant in the Valley. His column appears each Monday in The Recorder.