Introduction to Salt Dilution Gauging for Streamflow Measurement Part 2: Constant-rate Injection

Introduction Stream gauging by salt injection is a technique that will work in many streams in which current-meter measurements are unreliable. This extension note builds upon a previous Streamline article (Moore 2004b) and describes field and computational procedures for stream gauging by constant-rate salt injection. The emphasis is on small streams (less than about 2 m in wetted width) under low flow conditions (discharge less than about 100 L/s). A future article will introduce slug injection, which is better suited to gauging higher flows. Users are encouraged to experiment with the following procedure to suit individual circumstances.