Urban impacts on a prairie groundwater system : estimation of anthropogenic contributions of water and potential effects on water table development

xiii, 190 leaves : ill., maps ; 28 cm.In subhumid to arid climates throughout the world, recharge to groundwater in urban areas is often found to be higher than pre-urbanization rates, despite an increased percentage of impermeable surfaces. Groundwater recharge in the city of Lethbridge is substantially higher than recharge rates prior to urbanization, resulting in the formation of perched water table conditions. High perched water table conditions, typically at depths between one and 2.5 metres, have created problems for the City and University of Lethbridge, including the increased occurrence of slope failures along nearby coulees. This study estimates of the volume of excess water available for groundwater recharge through the practices of urban turfgrass irrigation, and water storage. Between May and September, 1990-1996 irrigation was applied far above evapotranspiration demands, resulting in large volumes of water available for groundwater recharge in the Varsity Village subdivision of the City of Lethbridge. The relationship between the amount of water applied and the development of perched water table systems was strong enough that equations between inputs and water table depth could be derived, and used to predict water table elevation