The document summarizes water monitoring efforts at several river catchment sites that drain into the Great Barrier Reef. Key details include: 1) Water samples are taken from sites near the end of river systems like the Barron, Johnstone, and Tully Rivers to monitor runoff entering the reef. 2) Gauging stations are used to collect discharge data and many have telemetry to provide near real-time data. 3) Equipment used includes gauges, sensors, and current meters maintained by the Hydrographic Support group to collect and store time series data.