Drilling groundwater wells in or near valleys is often beneficial due to natural water accumulation, shallow water tables, and good aquifer conditions. However, local geological assessment is crucial before drilling to ensure optimal well placement and sustainability.
the answer lies in the expectation of yours whether the valley is water recepient or descipient. because your vally may be dried or flooded. which one do you like actually?
the structure, formation, geological boundaries, aquifer grain size, depth and properties must be investigated before saying good or bad for the well borring in the valley. however, the question is a real challange to decide about easily.
Drilling groundwater wells near valleys is often more effective because valleys typically serve as natural collection points for surface water and groundwater flow, leading to higher water tables. The geology of valleys, including permeable sediment deposits, can enhance the availability of groundwater. However, local hydrogeological conditions, such as aquifer depth, soil permeability, and water quality, must be assessed to ensure well productivity and sustainability.