From the Maitland Mercury article by Chas Keys:
In 1982 the Department of Public Works, builder of the Lower Hunter Flood Mitigation Scheme, fixed more than a hundred flood markers to power poles within the City of Maitland.
They were in central Maitland, South Maitland, Louth Park, Horseshoe Bend, East Maitland, Lorn, Bolwarra, Pitnacree, Phoenix Park and elsewhere, and they indicated the peak level reached by the great flood of 1955.
Their siting was guided by maps made at the flood's peak and they were accurate to within about 150mm. They were important in helping people to understand just where the flood reached and how deep the water was. Some were more than four metres above ground level.
By 2008, about two thirds of the markers had disappeared.
Full article available at Maitland Mercury, Feb. 26, 2015.