Tabourie Lake Entrance Management Review

Shoalhaven City Council is currently reviewing the Entrance Management Policy for Tabourie Lake.

In conjunction with the NSW Government, Council is responsible for managing the entrance of Tabourie Lake for the purpose of flood mitigation. Due to the historical development of the catchment and development of the floodplain, low-lying properties are at risk of flooding under certain rainfall and entrance conditions. The Tabourie Lake Entrance Management Policy and Review of Environmental Factors (Peter Spurway & Assoc., 2005) (pdf 500KB) documents the procedure for opening the Lake.

This document has been in place for over 10 years now, and since then, Council has also updated the Tabourie Lake Floodplain Risk Management Study and Plan (FRMS&P) with better information. The FRMS&P was completed in 2016, and one of the recommended actions in the FRMS&P was to review the Draft EMP in light of the improved understanding of flood behaviour.

Therefore, Council has engaged consultants Cardno (NSW/ACT) to undertake a review of the document to ensure best practice is achieved in managing flood risk.


Background

Tabourie Lake is an ICOLL or Intermittently Closed and Open Lake or Lagoon. At times, the Lake is blocked off from the open ocean by a sand berm. The sand berm is formed by wave action across the estuary entrance. When the entrance is closed, there is no tidal flushing of the estuary and the water levels are largely controlled by catchment rainfall, with some potential for waves to overtop the berm. When Lake water levels rise in response to rainfall, the entrance berm may be breached and scoured away by floodwaters.

Due to the presence of low-lying development around the Lake, Council applies the Entrance Management Plan (Spurway and Assoc., 2005) to manage the impacts of flooding on infrastructure and properties. The Plan provides for mechanical opening of the Lake entrance by Council to artificially lower water levels.

Under the current Plan, the entrance is mechanically opened by Council when:

  • Lake water levels are equal to, or in excess of, 1.17 m AHD initiates an immediate entrance opening; or
  • Lake water levels stabilise after rainfall at a level between 1.00 m and 1.17 mAHD and a period of over two months has elapsed since attaining that level, resulting in nuisance flooding of foreshore land.

Given the significant amount of time that has passed since the EMP was prepared, and acknowledging the changes in the catchment and improved understanding of flood behaviour, Council is currently reviewing the EMP.


Shoalhaven City Council is currently reviewing the Entrance Management Policy for Tabourie Lake.

In conjunction with the NSW Government, Council is responsible for managing the entrance of Tabourie Lake for the purpose of flood mitigation. Due to the historical development of the catchment and development of the floodplain, low-lying properties are at risk of flooding under certain rainfall and entrance conditions. The Tabourie Lake Entrance Management Policy and Review of Environmental Factors (Peter Spurway & Assoc., 2005) (pdf 500KB) documents the procedure for opening the Lake.

This document has been in place for over 10 years now, and since then, Council has also updated the Tabourie Lake Floodplain Risk Management Study and Plan (FRMS&P) with better information. The FRMS&P was completed in 2016, and one of the recommended actions in the FRMS&P was to review the Draft EMP in light of the improved understanding of flood behaviour.

Therefore, Council has engaged consultants Cardno (NSW/ACT) to undertake a review of the document to ensure best practice is achieved in managing flood risk.


Background

Tabourie Lake is an ICOLL or Intermittently Closed and Open Lake or Lagoon. At times, the Lake is blocked off from the open ocean by a sand berm. The sand berm is formed by wave action across the estuary entrance. When the entrance is closed, there is no tidal flushing of the estuary and the water levels are largely controlled by catchment rainfall, with some potential for waves to overtop the berm. When Lake water levels rise in response to rainfall, the entrance berm may be breached and scoured away by floodwaters.

Due to the presence of low-lying development around the Lake, Council applies the Entrance Management Plan (Spurway and Assoc., 2005) to manage the impacts of flooding on infrastructure and properties. The Plan provides for mechanical opening of the Lake entrance by Council to artificially lower water levels.

Under the current Plan, the entrance is mechanically opened by Council when:

  • Lake water levels are equal to, or in excess of, 1.17 m AHD initiates an immediate entrance opening; or
  • Lake water levels stabilise after rainfall at a level between 1.00 m and 1.17 mAHD and a period of over two months has elapsed since attaining that level, resulting in nuisance flooding of foreshore land.

Given the significant amount of time that has passed since the EMP was prepared, and acknowledging the changes in the catchment and improved understanding of flood behaviour, Council is currently reviewing the EMP.


Feedback on the draft Entrance Management Policy for Tabourie Lake

Council is currently reviewing the Entrance Management Policy for Tabourie Lake.

Previous community engagement has been undertaken, including asking the community to indicate their preferred management option for the Lake. 

The draft Entrance Management Policy is now exhibited for members of the community to review and provide comment.

Please review the draft Policy and provide your feedback via the below form.

View the Full Document - Draft Entrance Management Policy - Tabourie Lake

View the Summary Document - Draft Entrance Management Policy - Tabourie Lake

Feedback opened on 21 January 2019 and will close on 22 March 2019

CLOSED: This survey has now closed.