Many years ago I recall the Water Corporation were criticized because the Derby Wastewater Treatment Plant was discharging to the environment. It seemed odd at the time because discharges in that location did not seem to be likely to cause problems. One of the last things we did on our recent trip out the Gibb River Road was to visit the Derby Wetlands. This is a wetland created by allowing controlled discharge from the very same wastewater treatment plant. It seems the discharges created an internationally important wetland and now this has to be maintained!
I think these are black winged stilts. Very elegant.