Tonle Sap : around November every year, at high water mark, the lake starts to drain into the Tonle Sap river and into the Mekong, The Tonle Sap river reverses flow and drains the lake down to about one third it’s high water size. Then in May or June, due to heavy build up of water in the Mekong, the Tonle Sap river again reverses flow and the lake starts to fill up again. Living on the edge of this lake is not practical. So, why not live in the lake ? With houses on stilts and farms on floating platforms.