Rupture of Ground Water Pumping Wells Related to Ground Fracturing Propagation in Queretaro City, Mexico

Compaction of sediments related to groundwater withdrawal has caused subsidence and ground fracturing in areas with rapidly increasing population of central Mexico. For instance, the City of Queretaro in the central part of Mexico depends mainly on groundwater supply that provoked a dramatic decline of the piezometric levels from a few to below 120 meters depth for the last three decades. The stratigraphic sequence of the Valley of Queretaro is characterized by a highly heterogeneous unsaturated sand-and-silt bearing sediments interbedded with pyroclastic layers and underlied by fractured basalts. The near surface fluvio-lacustrine deposits fill a fault-bounded basin that began to form in the Miocene. The main system of ground fractures and normal faults affecting the city is a long and narrow band (less than) with a ~N-S orientation, named Falla Central (FC). We present an analysis of the rupture and/or collapse of 15 pumping wells in Queretaro City that occurred in the last 12 years. The vertical deformation of the subsoil plays an important role in vertical and horizontal displacements in depth, which locate along the stratigraphic contacts between sediments and rocks. The distribution of hydraulic gradients is directly related with the displacements along contacts. Our results show that the propagation of fracturing form depth to surface causes the rupture of pumping wells and other urban infrastructure.