Measuring the height of flood water is an effective strategy for comparing the awful effect of floods on a community. This tree near Renmark South Australia is a river gum that is well over 200 years old. It has seen, and lived through, at least 16 floods so it is now referred to as the “Tree of Knowledge“. Imagine all the information your students can collect using this photograph. The official peak height was 10.2 metres, a gigantic amount of extra water. What was the height of all the other floods? You could replicate these heights in your school playground and imagine what it must be like to experience such an event.