Sustainability Challenges in Groundwater Management: Insights from 3D Hydrogeological Modeling in the Venetian-Friulian Plain.

The eastern portion of the Venetian Friulian Plain (north-eastern Italy) hosts a complex aquifer system, comprising several layered confined aquifers in the southern region and a thick phreatic aquifer in the north. These aquifers are critical for meeting the freshwater demands of the population, including drinking, industrial, agricultural, and sanitary needs. Approximately 60 m³/s of water is extracted through an estimated 50,000 wells, averaging 20 wells per square kilometer. A significant portion of this water, precise estimates are unavailable, is extracted far over the actual needs through flowing wells, operating 24h per day. These extraction practices are widespread in the region and are rooted in centuries-old legislation governing water rights tied to land ownership.
Although the region is classified as low-risk for water scarcity, the protracted droughts of 2022 forced seven municipalities to rely on alternative freshwater sources after several artesian wells ceased to function due to a significant drop in the water table. Moreover, monitoring data reveals concerning trends of aquifer depletion, with rates reaching up to 10 cm per year in some areas of the northern plain. This depletion, intensified by heavy extraction near the coastline, raises serious concerns about the long-term sustainability of current practices and the growing risk of saline intrusion.
This study marks a preliminary investigation of the current status of these water resources and evaluates the impact of groundwater extraction on depletion rates. A hydrogeological model of the VFP and the surrounding regions, including the Northern Adriatic Basin, was developed and a numerical groundwater model was run to simulate water levels and flux behaviour over a 23-year period (2000–2023). The simulations included two scenarios: one with active pumping wells and one without, to assess the impact of extraction on aquifer dynamics.
The results demonstrate that aquifer depletion is significantly affected by groundwater extraction, with localized areas experiencing depletion rates up to ten times higher due to pumping. The study also reveals offshore-directed and onshore-directed fluxes along the shoreline, both of which are impacted by well pumping, raising additional concerns about the potential of saltwater intrusion while simultaneously suggesting the presence of Offshore Freshened aquifers in the Northern Adriatic basin.
Overall, these findings highlight the potentially unsustainable nature of current groundwater extraction practices and underscore the urgent need for a comprehensive review of resource management and sustainability strategies.