CHARACTERISING BASEFLOW IN ISCHUA CREEK USING TEMPERATURE INFORMATION

Establishing ground-water discharge and recharge patterns along a creek can be important for studying contamination flow or estimating water budgets. Ground-water information can be difficult to retrieve in larger areas with little available data, because well monitoring and stream gaging is time consuming or expensive. It has been suggested that thermal data from a section of creek can be used to identify areas that are gaining or losing ground water. Temperature measurements were taken along Ischua Creek, Cattaraugus County, New York, from July to October 2001, in order to determine the ground-water/surface water interactions of the creek. Temperatures were measured along the entire length of Ischua Creek on several different days to examine the general thermal trends. Temperature history was taken from selected sites in the creek to collect long-term thermal data. Three sites were selected for long-term measurement, and at each site data loggers were installed in the creek at varying depths, from 6 to 24 inches, into the creek bed to determine the temperature signature at that site. The station data were used to account for the diurnal temperature changes present in the temperature surveys. A heat transport model was calibrated to temperature history to estimate ground-water flux to the stream. The collected data and model predictions suggest that the creek is mostly gaining with smaller areas of enhanced recharge.