Coastal Water Quality

Water quality programs in the area include the Long term Chlorophyll Monitoring Program (the Chlorophyll Program) and the Flood Monitoring Program. These programs are designed to define the nutrient status of the Great Barrier Reef, quantify increases in nutrients due to changes and determine the extent and actual influence that river waters have on the GBR.

The chlorophyll monitoring program demonstrates a difference in inshore and offshore waters most likely related to terrestrial discharge from the Herbert, Tully, Johnstone and Russell-Mulgrave Rivers. There is also a persistent and upward trend of increasing chlorophyll concentrations which may be related to the expansion of fertilised agriculture.

A long term flood monitoring program has monitored and measured flood plumes associated with cyclones from 1991 to 1999. The sampling events were Cyclones Joy (1991), Sadie (1994), Violet (1995), Ethel (1996), Justin (1997), Sid (1998) and Rona (1999). Concentrations of water quality parameters measured in the plume surface waters are almost always elevated in comparison to ambient water quality concentrations measured throughout the dry season.

Groundwater

A number of groundwater observation bores exist in the Johnstone basin. The total groundwater yield in the Johnstone basin is estimated to be some 122 000 megalitres per annum, of which some 50% is available for alluvial aquifers and some 40% from basalt aquifers.

Water quality is generally very good, with only very minor supplies within the metamorphic fractured rocks having total dissolved solids of over 3000 milligrams per litre. Some saltwater intrusion has occurred in the inlets of Liverpool Creek, Maria Creek, Johnstone River and Mourilyan Harbour.

A similar study on groundwater in the Johnstone Shire was also conducted as part of the Shire's environmental audit undertaken in 1992. The major findings of this study are summarised in the table below.

Atmospheric Management

There is limited information recorded and therefore reported in the Johnstone Shire. The only sampling points are located at point sources such as the sugar mills, abattoir and foundry. This sampling ensures that materials released from stacks are within the licence limits set by the EPA.

The only other information is anecdotal from complaints received by Council and the Environmental Protection Agency in relation to noise, odour and smoke. In the year 2000, 12 noise complaints, 13 odour complaints, and 3 complaints of incidents of dust were recorded.

The state of the atmosphere in the Shire is at present unknown due to a lack of atmospheric monitoring. Atmospheric pollution is not a community concern in the Shire and it is not anticipated that any further monitoring needs to occur.

Source: Australia Sugar Yearbook 1998