Understanding The Drying Wells of Madhesh: Looking through Hydrogeologists’ Eyes

Abstract

Madhesh Province is experiencing increasing groundwater stress, manifested by seasonal declines in groundwater levels and well/pumping failures, particularly during the pre-monsoon period. This paper examines the problem from a field hydrogeologist’s perspective by comparing two contrasting locations: Birgunj, an urban centre, and Mewa (Phatuwa Bijaypur) in Rautahat District, a rural agricultural area. The purpose is not to provide a statistically exhaustive province-wide assessment, but to illustrate how apparently similar well failures can arise from different hydrogeological conditions. The field evidence and hydrogeological interpretation indicate that the observed problem is more appropriately viewed as a groundwater-management and seasonal-stress problem than as evidence of permanent exhaustion of the regional aquifer system. Irregular and high-intensity rainfall, changes in land use and infiltration conditions, and increasing water requirements associated with population growth and intensified agriculture can increase groundwater stress. In Birgunj, concentrated abstraction from a low-storativity, confined and multilayered aquifer system produces rapid piezometric responses and seasonal pumping difficulties. In Mewa, the shallow phreatic aquifer has relatively high storage and responds more directly to local recharge, while observed domestic-well failures are often associated with well and pump limitations. The contrasting cases demonstrate the importance of considering aquifer-specific hydraulic characteristics when interpreting apparently drying wells and planning groundwater management.

 Madhesh Province is experiencing increasing groundwater stress, manifested by seasonal declines in groundwater levels and well/pumping failures, particularly during the pre-monsoon period. These two areas were selected to illustrate a general hydrogeological principle: how quickly and visibly a well fails is governed largely by the aquifer’s storage and pressure characteristics, not simply by the volume of water it contains. We argue that the apparently similar well failures reported across Madhesh often reflect groundwater-management problems and seasonal stress rather than permanent exhaustion of the regional aquifer system. This paper examines the problem from a field hydrogeologist’s perspective by comparing two contrasting locations: Birgunj, an urban centre, and Mewa (Phatuwa Bijaypur) in Rautahat District, a rural agricultural area. The purpose is not to provide a statistically exhaustive province-wide assessment, but to illustrate how apparently similar well failures can arise from different hydrogeological conditions. The field evidence and hydrogeological interpretation indicate that the observed problem is more appropriately viewed as a groundwater-management and seasonal-stress problem than as evidence of permanent exhaustion of the regional aquifer system. Irregular and high-intensity rainfall, changes in land use and infiltration conditions, and increasing water requirements associated with population growth and intensified agriculture can increase groundwater stress. In Birgunj, concentrated abstraction from a low-storativity, confined and multilayered aquifer system produces rapid piezometric responses and seasonal pumping difficulties. In Mewa, the shallow phreatic aquifer has relatively high storage and responds more directly to local recharge, while observed domestic-well failures are often associated with well and pump limitations. The contrasting cases demonstrate the importance of considering aquifer-specific hydraulic characteristics when interpreting apparently drying wells and planning groundwater management.