June is the time of year when one starts thinking a lot about water in Hong Kong. It gets especially humid and sultry in the Asian financial hub, the pools and beaches fill up, and the rain falls more frequently and violently. More broadly in Asia, the monsoon covers the months between April and September, with various rainy seasons arriving or ongoing in June for many countries. Water is a critical resource that is especially precious for local communities in the Global South. In Cambodia, the lake of Tonle Sap – the largest lake in the world – is one of the only major lakes that rises (June) and falls (November) by a stunning 6 meters. The dramatic rise and fall of Tonle Sap’s levels affects the ecosystem, fishing and tourism, and health. But with good management and community education, this need not be a peril but an opportunity.