Catchment Prioritisation

The Hornsby LGA lies within the broader Hawkesbury-Nepean catchment and partially the Sydney Harbour catchment, encompassing more than 1320km of creeks and rivers. The 4 major catchment areas in the Hornsby LGA are Berowra Creek, Cowan Creek, (upper) Lane Cove River and the Hawkesbury River. These catchments can be further categorised into 14 major stormwater sub-catchments and 55 smaller sub-catchments.

Waterway health ranges from pristine creeks, contained within National Parks, to highly modified and degraded systems downstream of urban and industrial areas. Council has limited funding available to protect and enhance waterway condition, so it is crucial this money is used most effectively. To ensure funding is targeted appropriately, Council has identified high priority sub-catchments where management actions could assist with the protection of higher value waterways from risks.

A preliminary risk assessment was completed for each sub-catchment based on an approach outlined by the State Government in the Risk-based framework for considering waterway health outcomes in strategic land use planning decisions. Each of the 55 minor sub-catchments were subsequently assigned a priority of low, medium, high or very high priority.

As a result of this study, Council has selected the headwaters of Berowra Creek in the south-western corner of the Shire as the priority catchment for further work and will be heavily focusing future catchment management activities in this area.

NSW Department of Planning and Environment have also developed a two page RbF case study using Hornsby Shire as an example of how existing data collected by Councils can be retrofit to apply the Risk-based Framework in a cost-effective way.

Useful links