Paso Robles vineyard irrigation study provides benchmark data to assist future area groundwater management

Management Act (SGMA) in California obligates increased levels of management in highand medium-priority groundwater basins in the near future in order to achieve long-term sustainable groundwater conditions (DWR 2014). An immediate challenge for effective management in many agricultural areas reliant upon groundwater is that little or no information currently exists on the amount of water extracted for irrigation at the individual farm level. Unlike users of developed surface water, growers who pump groundwater have generally never had to measure or report how much water they extract unless they are located in an adjudicated or actively managed basin. This lack of information on how much water is extracted can become a major handicap for any agency tasked with managing the groundwater supply in the near future, before metering becomes more widespread. Accurate information on extraction amounts and how these amounts can vary from year to year as a function of rainfall conditions will be critical in order RESEARCH ARTICLE