Our indicators

What is a report card?

What we do on the land impacts on the quality of water that runs off. If the quality of the runoff is poor, it puts stress on the environment. Stressors are changes to the environment that result from these activities and can lead to ecological harm.

Water quality monitoring can be undertaken to assess these stressors and their impact. In the MidCoast monitoring program we look at several indicators including chlorophyll-a (algae), seagrasses and turbidity.

Why a report card?

Report cards are an effective way to check on the health of our waterways when compared to other NSW waterways. They help us compare current conditions with the condition we would like them to be. Scientists use indicators to ‘health check’ our waterways. Just as your body temperature is used as an indicator that something may be wrong with your own health,

indicators are used to show if something is out of balance or unhealthy in the system. The indicators are selected to assess the overall health or ecological condition. The results of the Report Card are used to guide future management actions and ensure long-term ecological health of our catchments.

Report Card Results 2018 – 2020

During the period covered in this report there were three Waterway and Catchment Report Card monitoring programs undertaken and reported on. During that time a total of 18 sites across six catchments were monitored and of these sites eight maintained their 2018 grade in 2020, one site improved from its 2018 grade in 2020 and nine sites dropped a grade from 2018 to 2020.

It is important to note that the results during the period from 2018-2020 were heavily influenced by climatic conditions which included an extended drought, bushfires in large areas of the region which affected multiple catchments, followed by heavy rain periods with minor flooding. These climatic conditions must be considered when comparing the results.

Manning River estuary

The condition of the Manning River estuary remained relatively stable between 2018 and 2020 with most sites maintaining good ecological condition (B grade).

In 2018 three Manning River Estuary sites were monitored (Upper, Mid and Lower Estuary) while in 2019 and 2020 two additional sites were monitored (Dawson River Estuary and Farquhar Inlet).

In 2020 there was a change in results in the Upper Manning and Dawson River Estuaries to fair condition (C grade) while a continuation of the good ecological health results was recorded in the Mid and Lower Manning Estuaries and Farquhar Inlet.

Throughout the 2018-2020 period algal levels continued to be much higher than desired; this was particularly noticeable in the Dawson River and Upper Manning Estuaries. These results show there is a need for ongoing improvements in nutrient and sediment management from land use activities within the Manning catchment.

Khappinghat estuary

The Khappinghat estuary is located in Saltwater National Park so is expected to be in excellent ecological condition. However, in the period from 2018 – 2020 moderate algal growth and poorer than expected water clarity resulted in a drop from a good (B) grade in 2018 to a fair (C) grade in 2019 and 2020. It is important to note that the sampling periods were some of the driest on record followed by extensive fires through the catchment and very heavy rains which would have influenced these results.

Wallis Lake

The Wallis Lake system contains six monitoring sites. During the period 2018 to 2020 half of those sites maintained their grades, while the remaining sites dropped a grade.

During 2020 three sites (Charlotte Bay, Wallis Lake and Pipers Creek) received a good (B) grade while three sites (Mid Wallamba and Coolongolook estuaries and Wallamba Cove) received a fair (C) grade.

In Wallis Lake and Pipers Creek, the grade was influenced by both water clarity and algal levels. Higher than desirable algal growth in Charlotte Bay was also responsible for its drop in grade. In the Mid Wallamba and Coolongolook estuaries, water clarity was good but excess nutrient runoff resulted in much higher than desired algal growth. A drop in grade from good to fair in Wallamba Cove was the result of greater than desired algal growth showing that this site continues to be affected by stormwater runoff from Tuncurry.

Karuah River estuary

The Karuah River and The Branch estuaries have maintained a fair (C) grade throughout 2018 to 2020. These sites continued to show signs of significantly impaired estuary health with much higher than desired algal growth and good water clarity. Excess nutrient results indicate that there is a chronic flow of nutrients into the estuary from the Upper Catchment.

Smiths Lake

The grade for Smiths Lake remained in excellent condition (A grade) in 2018 and 2019 before a drop from excellent (A) to good (B) in 2020. The 2020 monitoring period presented challenging conditions including one of the driest summers on record followed by very heavy rain. The storms brought in nutrients which triggered excess algal growth resulting in the drop in grade.

Myall Lakes

Myall Lakes condition remained stable between 2018 and 2020 with all three sites in either excellent (A grade) or good (B grade) ecological health. Excess algal growth saw variation in the grades from year to year which emphasises the need to continue to reduce nutrient runoff from land use activities in the catchment.