Rural catchments are recognised as a major contributor to ongoing sediment and nutrient loads to the estuary. Local research reported that 10% of the eroded material from Wyong River was less than 0.15mm diameter and that streambank erosion had the potential to double Total Suspended Solid (TSS) loads discharging to the estuary (OEH, 2011). Fine sediment is known to smother aquatic vegetation, increase turbidity and significantly affect the distribution and abundance of seagrass in Tuggerah Lakes (OEH, 2012). Similarly, excess macronutrients can be bound to sediment which is carried to the estuary and can exacerbate algal blooms and symptoms of eutrophication.
For these reasons, “stabilising foreshore and streambank erosion” was identified as a priority program in the Tuggerah Lakes Estuary Management Plan. Instream and bank rehabilitation works are typically supported by additional work in the surrounding riparian corridor. This improves the overall resilience and ecological value of the site. Riparian restoration works include site stabilisation, weed control, revegetation with locally native plants and fencing to exclude livestock. In many cases, we work with local landholders and Local land Services to achieve these outcomes.
Rehabilitating streambanks and riparian corridors has been an ongoing activity for many years, with over 50km completed since 2008. Recent works have been completed along the banks of Spring Creek, Wallarah Creek, Wyong River and Ourimbah Creek. A targeted program of Camphor Laurel control (Cinnamomum camphora) was also undertaken throughout the Wyong River and Ourimbah Creek catchments.
These projects have been made possible with the support of Australian Government funding, and working in partnership with Local Land Services, local landowners, and environmental groups.