An assessment was made of the potential for using various management options, involving wetland filters, to reduce phosphorus loadings into Harvey Estuary, The study involved a literature survey, study of existing wetlands in the Harvey catchment, and examination of phosphorus uptake by experimental wetlands. Up to 90% reduction in phosphorus concentration was achieved at high input concentration and low flow rates, However, the use of artificial wetlands along the borders or outlets of drains was not considered feasible, as high rates of water movement into the drainage system would preclude efficient phosphorus retention by the filter. The use of artificial wetlands at the outlet of certain point sources, e,g, piggeries, is likely to be effective, although further work on design and efficiency of the wetland filter would be required before implementation.

Diversion of agricultural runoff into existing natural wetlands was not recommended as the majority of wetlands in the catchment have higher phosphorus concentrations than the runoff, due to removal of fringing vegetation from swamps in farmland. Overflow from these swamps into drainage canals may provide a significant source of phosphorus to the estuary, although the actual quantity, on a catchment basis, is not known. There appears to be no practicable way of reducing the amount of phosphorus contributed in this overflowing water, which would be effective in the short term. In the long term, reintroduction of fringing vegetation (including sedges and trees) sited around wetlands and at areas of overflow, may be profitable.

In June 1983 the Department of Lands and Surveys received a request from the Town of Geraldton to have the foreshore areas within the town vested in Council. That request was accepted on the basis that Council accept responsibility for management as prescribed by the Department of Conservation and Environment (DCE).

Council agreed to this and on 27 February 1984 the Department of Lands and Surveys asked the DCE to prepare a Coastal Management Plan for the coastal area within the jurisdiction of the Town of Geraldton. In April 1984 the DCE commenced to gather information to prepare a Coastal Management Plan for Geraldton, in consultation with the Town Council and various government bodies and groups with interests in Geraldton's coastal zone.