Groundwater overexploitation: Numerical modeling in a test zone of the Lucca Plain

Numerical modelling is powerful in forecasting and managing groundwater shortage crisis, but in order to overcome its somehow “exoteric fame” with public Italian authorities it needs real world, local field tests. The multilayered aquifer of Lucca-Bientina plains (Northern Tuscany) shows severe piezometric drop as a consequence of unregulated competition between agriculture, paper mills, public and private drinking water wells. The crisis is evolving with subsidence and the appearance of little sinkholes. This area has been chosen in order to test finite difference numeric model as a crisis forecasting and analysis tool and as a regulatory actions virtual test bench. The geological model of the area has been translated in a Modflow grid. Head measurement points have been selected among existing wells and boreholes and they have been monthly surveyed since January 2007. Calibration achieved a good statistical correspondence with reality. Long and short term simulations have been performed in order to forecast middle term effects of actual overexploitation, rainfall trend and rearrangement of main boreholes fields distribution