Entrance Management

Overview

The Shoalhaven City Council manages 11 of 102 Intermittently Closed and Open Lakes and Lagoons (ICOLLs) in NSW.

The natural opening and closing of ICOLLs occurs on an irregular basis. There are several factors that contribute to entrance conditions including rainfall and ocean conditions.

Entrance closures

Generally, a lake or river entrance is closed by waves triggered from a severe ocean storm for example an East Coast Low, resulting in washing sand into the entrance channel restricting tidal flow.

When tidal flow is restricted over time this gradually leads to the closure of the entrance channel until the point of complete closure. A series of ocean storms can accelerate this process.

Entrance openings

Following an entrance closure, it may open naturally from a flood which scours a channel through the spit and the typical tidal regime resumes.

A large flood is required to establish a substantial enough channel to ensure a viable long-term open entrance.

What we do to manage ICOLL entrances

Due to increased development in low lying areas, and their tourist value, the Shoalhaven ICOLLs have been under increased pressure.

Council in partnership with state agencies and its community has developed Entrance Management Plans (EMP).

View our entrance management plans

Council, in partnership with state agencies and relevant communities, has developed entrance management plans.

The completion of flood risk management plans will trigger a review of these plans.

Flood risk management plans

The feasibility of permanent flood mitigation and entrance management options such as engineered options or strategic planning considering current climate change predictions are investigated in the Floodplain Risk Management Plans.

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Last updated on 03 September 2021