data live sydneyGreater Sydney Dam Levels. Greater Sydney catchment rainfall, total storage and water supply. HOW MUCH RAIN HAVE WE HAD? 3.3MM. 8.9MM FOR THE LAST WEEK.Greater Sydney Dam Levels. Greater Sydney catchment rainfall, total storage and water supply. HOW MUCH RAIN HAVE WE HAD? 3.3MM. 8.9MM FOR THE LAST WEEK.