WATER SOURCE AND DISCHARGE RATES FROM MULI-LAYERED BEDROCK AQUIFERS

As bedrock aquifers in the Denver Basin change from confined to unconfined conditions and start draining the upper portions of the saturated material, it is not immediately obvious how the water levels in supply wells can be expected to change and which layers are expected to continue to produce water. The change in pumping water level with time and changing discharge rates from individual layers may be a function of the vertical conductance of confining layers between the producing beds.

Simulations will be performed using HRS's Multi-Completion Well package to try to identify characteristics of water level change in Denver Basin pumping wells which may provide insight into how the aquifers can be expected to drain over time. Issues to be addressed: · Does the rate at which water can be withdrawn from a draining well depend on the vertical conductance of confining layers? · Are there characteristics of the temporal pattern of water level change in draining wells which indicate if the confining layers are low or high conductance? · Are there specific types of data which can be gathered to help water suppliers better determine how the aquifers can be expected to act in the future?