The Black Water is a drain technically, I believe it was even man-made during the conversion of the Kongahu swamp.  Now it is a semi-natural waterway that has been adopted by plants and wildlife alike. It runs through a very pretty agricultural environment with a background of the southern ranges. It is a favourite haunt for ducks and waders and many sea birds as well. I find the way light plays on it and the constant changes in growth around it quite fascinating.