Catchment science helps us understand the impact of pollution in the catchments and plays a significant role in protecting water quality.
Sound science helps us to make good decisions. The Sydney Catchment Authority uses science to investigate whether specific catchment management actions will actually be effective. It is also used to test assumptions about water quality to discover whether they are valid.
The Sydney Catchment Authority science program is organised around five science disciplines:
- nutrients, sediments and pollutants
- climate variability and extreme events
These disciplines are used to help water quality planning.
Some of the Sydney Catchment Authority's research projects are outlined below.
Pathogen budgets for Sydney Catchment Authority sub-catchments (with the University of NSW)
This ongoing study is developing and prioritising an assessment of land uses according to their potential role in contributing pathogens to the drinking water catchment. It is informing rectification actions to minimise human health risk from catchment activities.
The study examines relative quantities of Cryptosporidium, Giardia and E. coli in streams in a sub-catchment as a function of land use.
An initial study identified different potential risk factors. Further studies are focused on three research areas:
- animals, including livestock, native and feral populations
- sewage treatment plants
- new molecular methods to improve pathogen detection.
Native animals as human pathogen sources (with Macquarie University)
This study is concluding an investigation of whether native animals, particularly Eastern Grey Kangaroos, carry Cryptosporidium and/or Giardia.
The study has examined the populations that are present in the Warragamba Special Area and how they interact with water. Droppings were collected to analyse quantity, distribution and genotype of pathogens.
The study has found that kangaroos do not carry Cryptosporidium types that have caused a water-borne outbreak of disease.
Livestock movement in relation to waterways (with University of NSW)
Cattle are known carriers of human-infective Cryptosporidium and can spend large amounts of time in and around waterways. This study is investigating whether providing alternative watering locations, shade, dry ground and feeding sites can encourage cattle away from waterways without the need for exclusion fencing, which is expensive and inflexible.
The study is providing alternative watering locations, monitoring cattle movements, monitoring water quality, collecting droppings and calculating pathogen loads.
The outcomes are informing SCA policy and practices in working with landowners to better manage grazing lands in the catchments.
Relative pathogen risks from sewage treatment plants (with University of NSW)
This study is investigating relative pathogen risks from sewage treatment plants around the Sydney drinking water catchments compared to other sources of pathogens.
This study is using innovative risk assessment methods and new pathogen analytical techniques to risk rank the sources of pathogens in subcatchments that contain a sewage treatment plant.
The study is collecting water samples at different stages of treatment, monitoring raw inflows and final effluent, and calculating pathogen loads discharged to the environment.
Developing molecular tools to determine Cryptosporidium genotypes (with Murdoch University WA)
Not all Cryptosporidium are infective to humans. This study is examining which types are present in the drinking water catchment and identifying their host animals.
The study is collecting droppings and contaminated samples, and genotyping the samples present.
Interim findings are informing operational and health risk management decisions related to water supply.
Molecular methods for tracing faecal viruses (with the University of NSW)
This study has developed tools to trace and 'fingerprint' sources of viruses that cause gastroenteritis in sewage and drinking water catchment waterways.
The study involved molecular identification of genomes of common enteric viruses.
The methods developed in this project have been transferred to the SCA's analytical laboratory service providers.