Heat and Chloride Inflow into the Puarenga Stream from Whakarewarewa

Abstract

The Puarenga Stream forms part of the boundary of the Whakarewarewa area and carries the discharge from Whaka to Lake Rotorua. Fifteen minute flow and temperature gaugings are mads at H e m o Gorge upstream of Whaka and at P.R.I. bridge downstream. Mean daily estimates of the heat flow into the stream and the enthalpy of this flow are made and show changes with rainfall and air temperature, but have otherwise remained fairly constant. The stream has been sampled on 21 occasions over a two year period. A l l samples were analysed for chlorlde, and sulphate. Solar heating effects and the stream flow time between Gorge and F.R.I. bridge have been taken account. The chloride content of the inflow and enthalpy, show a linear relationship which extrapolates well to other features in the area. The chloride inflow Is generally constant but shows definite low values. a mixing of spring discharges and groundwater.