Scientific Investigations Report 2008–5071
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2008–5071
Conceptual Model of Hydrologic and Thermal Conditions
A numerical model of the Eastbank Aquifer system would be useful for evaluating potential future hydrologic and thermal effects of different ground-water pumping rates, timing, and locations. Specifically, a model would help determine if there may be pumping alternatives that can meet the water demand by the Eastbank Hatchery and the regional water system and also provide sufficiently cool water for the hatchery. Numerical modeling can be achieved by verifying and updating the numerical model of the Eastbank Aquifer system by Water & Environmental Systems Technology, Inc. (1990) or by constructing a new model. Updating or constructing a numerical model would benefit from the following data, collected over a period of at least a year:
Regular verification and calibration of instruments and detailed records of the verification and calibration will ensure that reliable data are collected. Detailed records of instrument replacements and other significant events that may affect the pumpage, water-level, and water-temperature data may help explain possible data anomalies.
A numerical model of the Eastbank Aquifer system would be more reliable if detailed information were available about the source of the water flowing through the North and South Weirs and if the presence of a bedrock depression near the RW well field could be determined by drilling a new well. The depth to bedrock, the nature of the sediments above the bedrock, and the age and temperature of ground water in the depression could be evaluated as part of the drilling process.