Water quality at Tilba Tilba Lake

Local landholders are leading efforts to restore vegetation at Tilba Tilba Lake and Victoria Creek to improve the ecosystem health.

Assessing riparian vegetation at Victoria Creek, Tilba Tilba Lake catchment

At Victoria Creek and Tilba Tilba Lake on the NSW South Coast, many years of clearing vegetation and livestock accessing the water have caused bank erosion, sedimentation and bacterial contamination from livestock trampling the banks and faeces washing into the waterway.

As a result, the lake has received poor to fair ecological health scores compared to similar coastal lakes across New South Wales.

To improve the health of Victoria Creek and Tilba Tilba Lake, the Marine Estate Management Strategy has funded a series of rehabilitation activities since 2019, coordinated by South East Local Land Services with landowners and local Wagonga Aboriginal rangers.

These activities will have a range of social, economic and environmental benefits for the surrounding environment and landowners, with the goal of improving the system health of Victoria Creek and Tilba Tilba Lake.

Our scientists were engaged to develop a scientifically rigorous monitoring program to better understand the ecosystem health of Victoria Creek and Tilba Tilba Lake system and determine the baseline conditions for the system.

The rehabilitation project involved landowners and Wagonga Aboriginal rangers:

  • replanting riparian vegetation (the trees and shrubs lining the fringes of waterways) with appropriate native species
  • installing new fencing to prevent cattle from entering the waterways
  • adding water troughs to provide new drinking points for livestock.

Over time, we expect to see:

  • creek banks becoming stabilised by the increased riparian vegetation
  • less erosion
  • more habitat and shade along the creek
  • greater diversity of species including frogs, fish and water-bugs.

By excluding livestock near the creek and lake, we’ll also see improvements to ground cover, bank stability. instream vegetation and bacterial and nutrient levels in water.

As a result of improvements to the ecosystem, landowners will benefit from improved health and productivity of livestock due to:

  • better shelter from more trees
  • access to high-quality water which will increase water and forage intake and lead to weight gain and higher milk production
  • reduced risk of stock diseases including mastitis.

More native vegetation on their land will also increase its value, and landowners may have a greater sense of wellbeing from their contribution to nature conservation.

It may be many years until we see big improvements in Victoria Creek and Tilba Tilba Lake, but the more people that come on board to undertake improvement works on their land adjacent to the creek and lake system, the greater the results will be.

Long-term monitoring is important as we know it could take many years to see an improvement in ecological health after management actions such as riparian replanting and stock exclusion fencing.

Our scientists have assessed several key environmental indicators at Victoria Creek and Tilba Tilba Lake to understand the baseline conditions of the system. This data will help us track improvement over time as we can compare it to similar data collected through future routine monitoring programs.

In 2019, about 43% of the catchment was covered with woody vegetation. Most of the woodland and forest area is in the upper catchment of Victoria Creek within the Gulaga National Park, and in the northeast of the catchment at Corunna State Forest.

There were several key findings of our baseline study:

  • Victoria Creek is still in relatively poor condition with slumped and eroded stream banks, high concentrations of nutrients (nitrogen and phosphorus), low dissolved oxygen and the presence of faecal bacteria.
  • The good news is 3 species of frogs, abundant and diverse fish species and the presence of water bug communities suggest the creek has a lot of potential to recover given the right conditions.
  • Fencing has reduced grazing pressure on the riparian vegetation along Victoria Creek and on saltmarsh along the foreshore of Tilba Tilba Lake, allowing it to recover. Saltmarsh has started to come back and spread out.
  • Water quality at Tilba Tilba Lake continues to fluctuate with high concentrations of nutrients and poor water clarity which can lead to algal blooms and poor visibility.

Read the baseline report  Access the data

The monitoring of water quality, macroinvertebrates, vegetation and saltmarsh communities around Victoria creek and the Tilba Tilba lake system is ongoing and has great community support from the Tilba Tilba local community.

Through monitoring and continued rehabilitation works carried out with help from the community, we expect an improvement in the health of the Tilba Tilba Lake and Victoria Creek system and a range of positive benefits for landowners and the wider community.

These projects are funded by the NSW Government under the 10-year Marine Estate Management Strategy, which was developed by the NSW Marine Estate Management Authority to coordinate the management of the marine estate.