Big Data Offers Promise Of Better Groundwater Management In California Analysis of 200,000 groundwater samples reveals major mismatch in California groundwater data To ensure that California’s groundwater is sustainably managed in the future and over the long-term, current state definitions of what constitutes groundwater may need to be revised, according to research published this week in PNAS. A McGill University-led research team has analyzed big data of more than 200,000 groundwater samples taken from across the state and found that there are problems with the guidelines used for groundwater management. Known as the ‘Base of Fresh Water’, the guidelines are close to fifty years old and don’t reflect current uses, knowledge, concerns or technologies related to managing groundwater in this coastal state with a multi-billion-dollar agricultural industry.