[gallery link="file" ids="4151,4152,4159,4158,4157,4156,4155,4154,4153"] Waterhen Lake was breathed into life in the 1970s. The lake's primary purpose was to be used only as a stormwater retention basin for the collection of runoff from the surrounding hills, the settling of sediment, then outflow into the Coomera River. Over time, of course, the hills are now suburbs and runoff includes garden fertilisers, grey water and road accretions. The lake has an average depth of around 400mm, with some deeper sections of 1.6metres due to the island wildlife refuge having been excavated from the bed of the lake. Over time the entire lake and island have become increasingly used by breeding birds (primarily ibis which are native to Australia, egrets of all four species – cattle, little, intermediate, and great eastern – little…