Case study of horizontal collector well for river bank filtration in Paußnitz, the free state of Saxony, Germany
摘要
To meet the rising water demand in Northern Saxony and capitalize on the advantages of horizontal collector wells (HCW), this marks the first-ever implementation of HCW for water supply in the region. Through a comprehensive analysis of hydrogeological and geophysical studies, the optimal locations for HCW were identified in Paußnitz, with a targeted average extraction volume of 6000 m3/d. Since its implementation in 2016, HCW has functioned well, experiencing no operational issues. Key parameters such as pumping rate and groundwater level have been recorded both in the HCW itself and in several observation wells. The collected data underwent analysis to ascertain the advantages of HCW over vertical alternatives. The correlation coefficient of water levels between groundwater and the Elbe River indicates a robust relationship with minimal time lag of intraday. Despite extracting high amount of groundwater, observations near HCW are still influenced by the Elbe River. Moreover, there is consistency in flow distribution among all laterals, while significant differences in pumping rates exist. Notably, HCW exhibits minimal drawdown and remains affected by bank filtration, contributing to its overall high performance. Furthermore, utilizing daily measurement values for pumping rate in HCW and groundwater level in observation wells, transmissivity of around 1800 m2/d and hydraulic conductivity of 1.5 × 10−3 m/s were calculated, and it agrees strongly with the hydrogeological features in the study area. This pioneering application of HCW has exceeded practical expectations, providing evidence of its practical viability and numerous advantages in river bank filtration over alternative water supply methods.