What is the Catchment Remediation Rate (CRR)

The Catchments Remediation Rate (CRR) is a special rate paid by Hornsby Shire residents to fund projects that repair and protect local waterways. All catchments impact on water quality and all rateable properties within these catchments benefit from the environmental and water quality improvements, in terms of improved quality of life for ratepayers.

CRR is levied at 5% of Council’s total ordinary rate revenue, on all properties throughout the Shire on an ad valorem basis. Since July 1994, the CRR has generated over $50 million. In 2020/21, income received from the CRR special rate was $2.97 million. These funds have been dedicated to improving water quality across the Hornsby Shire through a combination of both capital and non-capital works. Over 400 water quality improvement assets have been constructed and installed to date, preventing thousands of tonnes of pollution, including litter, sediment and organic matter from entering our waterways. There have been more than 4000 tonnes of waste removed from stormwater treatment devices in the past 4 years alone.

The program also supports a number of pollution prevention initiatives such as environmental education, industrial auditing, street sweeping, and emergency spill response and pollution regulation.

In addition to the pollution treatment and prevention initiatives, the CRR funds ongoing works associated with the maintenance and monitoring of these assets and the receiving waterways. Through regular and proactive maintenance of water quality assets, Council can ensure the assets are operating to their full potential thereby resulting in a better environmental outcome.

Water quality monitoring data is collected using physical, chemical and biological indicators of waterway health. This data helps Council prioritise future remediation works, identify areas where environmental degradation is occurring and to assess long term water quality improvements.

The 1970s and 1980s saw the increasing urbanisation of Hornsby’s sensitive bushland catchments and an influx of tens of thousands of new residents. Sediment runoff from developing and newly developed residential areas and nutrient pollution from sewage treatment plants contributed to the deteriorating quality of local creeks and estuaries.

Unsavoury smells from the natural waterways became more potent and more common; algal blooms were becoming more substantial and more frequent; run off and sewage overflows in wet seasons became more difficult to manage; frog watchers noted the loss of familiar species; recreational fishermen caught fish with black livers; bush walkers watched weeds intrude into relatively pristine natural reserves; indigenous plants died or were depleted by theft; and locals watched the sea grass retreat under increasingly muddy water.

Source: A New Legend – The Story of the Berowra Creek Community Contract (PDF 10.5MB)

By the 1990s it was clear that Hornsby Shire’s waterways were under severe stress. Berowra Creek was being despoiled by instances of fish kills and algal blooms. Urgent action was needed.

To force the State Government to see how desperate the situation was Hornsby Shire Council placed a moratorium on the processing of any development application located within the West Hornsby Sewage Treatment Plant’s catchment area until action was taken.

The strategy worked and in April 1994 a Statement of Joint Intent (SoJI) was signed between Hornsby Shire Council, NSW Government, Environment Protection Authority, (Sydney) Water Board and the Hawkesbury-Nepean Catchment Management Trust. The principal intent behind this “community contract” was the ecologically sustainable development of Berowra Creek catchment and recovery of the environmental health of the Creek.

The SoJI not only acknowledged the significant impacts of polluted urban stormwater run-off but instigated the upgrading of the West Hornsby and Hornsby Heights Sewage Treatment Plants (reducing nutrients through increased levels of wastewater treatment) and the creation of the CRR.

  • Water quality / biological treatment of stormwater pollution
  • Reduction of pollution loads impacting the terrestrial environment and waterways
  • Enhancement and protection of indigenous habitat
  • Reduction of wastewater flows and flooding impacts
  • Reduction of the dependency of potable water and cost savings from reusing water
  • Engagement of WSUD, ecological sustainability and water conservation practices.

Biofiltration Basins

Biofiltration basins are landscaped vegetated basins used to slow and treat stormwater runoff. Stormwater is directed into the basin where the stormwater percolates downwards through almost a metre of loamy sand, removing pollutants (e.g. nutrients and heavy metals) through physical, chemical and biological processes, including filtration, plant uptake and microbial activity.

Gross Pollutant Traps

Gross pollutant traps can be nets, screens, racks or underground vaults that capture gross pollutants such as litter, organic matter and coarse sediment from stormwater runoff.

Stormwater Harvesting

Harvested stormwater is treated and stored for reuse in sports field irrigation. Stormwater harvesting collects runoff water from pipes and surface drains whereas rainwater harvesting collects water directly from roofs.

  • Maintenance of stormwater quality improvement devices
  • Water quality monitoring and research
  • Environmental education
  • Street sweeping
  • Industrial auditing
  • Emergency spill response
  • Environmental compliance and management.

View videos that give full account of the dramatic events that led to the creation of the CRR.