Agricultural water conservation and efficiency in California: a special focus on the Delta
The Sacramento-San Joaquin Delta is a critical resource. Almost half of the water used for California’s agriculture comes from rivers that once flowed to the Delta and more than half of Californians rely on water conveyed through the Delta for at least some of their water supply. The Delta also provides habitat for 700 native plant and animal species. This important region is now in a serious, long-term crisis. Major threats include rapidly declining populations of threatened and endangered fish; increasing risk of levee failure due to earthquakes and decades of neglect; rising seas and changes in frequency and intensity of floods and droughts due to climate changes; and worsening water quality.
A key finding of recent court decisions, scientific assessments, and the Delta Vision Blue Ribbon Task Force is that the absolute volume of water exported from the Delta is too high, or is so at critical times. Given that agriculture accounts for about 80% of Delta water consumption, no economic, environmental, or policy assessment can be complete without a serious examination of agricultural water withdrawals from the Delta.
This report looks at four scenarios for increasing agricultural water-use efficiency. Our central findings show that improving agricultural water-use efficiency through careful planning; adopting existing, cost-effective technologies and management practices; and implementing feasible policy changes can maintain a strong agricultural sector in California while reducing pressures on the Delta. Reducing water use can also create a more resilient agricultural sector by
increasing the quantity of water in storage, reducing the risk of drought, and improving the reliability of the available water. In addition, certain water conservation and efficiency improvements actually increase farm productivity and profitability, further bolstering the agricultural sector.
Reductions in the amount of Delta water available to the agricultural sector are already occurring. Despite record production in counties throughout the Central Valley in 2007,4 recent water shortages resulting from the drought and legally-mandated Delta pumping restrictions have resulted in total farm losses that some estimate to be as high as $245 million as of mid-summer 2008.5 The consequences of future sudden shortages or disruptions in water supplies from the Delta on local economies and the state can be far less severe if focused efforts to improve efficiency are implemented early and intentionally.