See the ‘Mornington Catchment’ page for a detailed description of the catchment.
This Report Card provides an overview of water quality in the Mornington catchment from 1 July 2015 to 30 June 2016. The quality of the water is given an overall score by combining the results of six standard water quality parameters: nutrients, water clarity (turbidity), dissolved oxygen, salinity (conductivity), pH (acidity/alkalinity) and metals.
In 2015–16, water quality in the Mornington catchment was ‘Very Poor’.
Summary Table: The table below shows the percentage of the Mornington catchment that falls into each scoring category. See scoring method for more information.
Waterways in the rural areas
Rural drainage to small tributaries in urbanised beach suburbs
The routine monitoring at five sites gives us information for about 94 per cent of the catchment. The remaining six per cent of the unmonitored catchment consists of mostly urban waterways, which would typically score as ‘Very Poor’ for this region.
See the Monitoring Programs page for changes to the monitoring program.
The section 'Changes over time’ compares this year’s annual index scores and indicators with Mornington’s scores from previous Report Cards (since 2000). Results can also be compared to other catchments.
Site-specific details about parameters can be accessed via the map.
Water quality in the Mornington catchment is ‘Very Poor’.
Water quality in waterways of the Mornington area is influenced by runoff from intensive horticultural and farming activities in the central part of the catchment and polluted runoff from urban coastal towns. Residential and industrial areas also contribute to the poor water quality. Sediment and metals carried in runoff are a particular problem.
Monitoring sites situated along the coast tend to be affected by runoff from the upper rural areas, as well as runoff from urban areas along the coast
Although the individual site scores ranged from ‘Poor’ to ‘Very Poor’, some smaller waterways of the Mornington catchment had indicators, such as water clarity and pH, that were rated ‘Fair’ to ‘Very Good’.
Short-lived environmental and extreme weather events can impact water quality in waterways. Long-term dry spells can result in reduced river flows, increases in salinity and algal blooms, while heavy rainfalls can cause flooding and river bank erosion, and wash sediments, nutrients and pollutants into waterways.
Below average rainfall was observed in 2015–16. The Bureau of Meteorology (2016) noted just one day when significant rainfall (27 mm) was recorded.
Outside of this date, no significant environmental or weather events were recorded for the period that would have significantly affected water quality.
Although ‘Poor’ to ‘Very Poor’ water quality has been a persistent feature in the Mornington catchment over the past 16 years, water quality improved slightly in 2009–10 and in 2012–13. These were both short-lived improvements as water quality declined to pre-2009 levels in the two years that followed. Water quality improved marginally this year, with slightly lower levels of nutrients and improved dissolved oxygen levels.
Improvements in water quality can be difficult to achieve in catchments with heavy urban or agricultural land use, where the source of many pollutants is diverse and widely spread across the catchment. Therefore, the installation of water sensitive urban design features such as rainwater tanks, raingardens and roadside swales (vegetated ditches that collect runoff) play an important role in reducing the transport of these pollutants into waterways.
Government agencies, local councils and the community have implemented a range of initiatives to improve waterway health in the Mornington catchment:
Environment Protection Authority (EPA)
A number of priority areas and actions have been identified in the Mornington catchment to build on existing projects and initiatives. These include:
The following figures show a comparison of scores for each identified water quality indicator in the catchments and Port Phillip Bay.