Assessing the impact of large-scale dewatering on fault-controlled aquifer systems: a case study in the Acque Albule basin (Tivoli, central Italy)

Abstract

The development of large-scale bedrock quarry operations often requires high-volume and long-term groundwater extraction to maintain a sustainable working environment. These dewatering activities often influence groundwater levels and flow patterns regionally. In the present study, the influence of the dewatering of the travertine quarry operations near the city of Tivoli, Italy, are quantitatively investigated through an integrated analysis of field data and numerical modeling. Lowering of regional groundwater levels in the vicinity of the quarry has led to destructive land subsidence and alterations to the flow system sustaining a hot-spring area. The study employs a finite element numerical model (FEFLOW) to evaluate and quantify the impact of the extensive dewatering on fault-controlled regional groundwater flow in the Acque Albule basin. By incorporating the physical field data and historical hydrologic information, the numerical model was calibrated against three groundwater scenarios, reproducing the effects of different exploitation activities, coupled with natural changes over the course of the quarry operation. The results indicate that groundwater withdrawals by the mining industry and by "Terme di Roma" spa resulted in the cessation of flow from the primary thermal spring and a drop in the phreatic level in the area consequently affected by land subsidence

Groundwater flow and geochemical modeling of the Acque Albule thermal basin (Central Italy): a conceptual model for evaluating influences of human exploitation on flowpath and thermal resource availability

“…The Acque Albule Basin is a morphological depression located about 20 km east of Rome (Central Italy) at the eastern margin of the Central Apennine fold -thrust belt, covering an area of approximately 30 km 2 (Brunetti et al 2013). During the Pliocene the area was affected by tectonic activities which allowed the upward movement of deep hydrothermal fluids, causing the deposition of an endogenic travertine sequence (De Filippis et al 2013).…”

“…The area encompassed by the quarries is approximately 4.7 km 2 and is situated between several recent urban settlements. The Regina and Colonnelle springs are the main thermal springs of the aquifer, located approximately 1 km NW of the extraction area, along a N-S shear fault zone, with an average temperature of 23-24 °C and a mean discharge of about 2.5 m 3 /s (Lombardi 2005;Brunetti et al 2013). The dewatering process due to the travertine mining operations at the pit floor, coupled with the extraction activities performed to supply the Rome Thermal SPA, has remarkable effects on the water table level in the travertine aquifer and on the discharge of the above-mentioned natural thermal springs.…”

“…The dewatering process due to the travertine mining operations at the pit floor, coupled with the extraction activities performed to supply the Rome Thermal SPA, has remarkable effects on the water table level in the travertine aquifer and on the discharge of the above-mentioned natural thermal springs. These activities in the basin also resulted in damage to private buildings in the urbanized area surrounding the travertine quarries, due to land subsidence beginning in July 2003, when the Italian government declared a state of emergency in the Municipalities of Tivoli and Guidonia (Brunetti et al 2013).…”

“…Many conceptual models have been proposed for the study site (Petitta et al 2011;La Vigna et al 2011;Carucci et al 2012;Brunetti et al 2013;La Vigna et al 2013), analyzing the area based on hydrogeologic, hydrodynamic and hydrogeochemical data. These studies have substantially contributed to addressing several aspects concerning groundwater flow, interaction between different aquifers, mixing of waters of different origin and water-rock interactions.…”

“…) temporary ceased. Since July 2007 this supply system has been replaced by two wells (W1 and W2) and connected to the Regina and Colonnelle springs (S1) via an underground pipeline (Brunetti et al 2013).…”