What is that strange structure on the edge of Emigrant Ck?
LIKE some kind of medieval defence device, strange log structures have emerged from the banks of Emigrant Ck - but far from warding off marauding armies, they are protecting the environment and the habitats of the creatures that live there.
The log structures were introduced in the Emigrant Creek estuary as an environmentally sensitive erosion control measure, providing habitat for mangroves and fish and improving water quality and protecting land for horticultural.
Local Land Services' Natural Assets Team designed a unique log fillet to arrest severe erosion and it was constructed by the organisation's Soil Conservation Services arm.
Senior Land Services officer with North Coast Local Land Services. Shaun Morris said: "The use of log fillets for erosion management benefits both the landholder and the estuary".
"Log fillets are structures built in front of an eroding bank to absorb wave action and create an area of still water between the fillet and the eroding bank, encouraging the collection of sediment and providing a habitat suitable for regeneration of mangroves.
"These unique wood designs reduce wind and wave wash from boat traffic impacting the mangrove nursery. The shape also promotes the deposition of sediment behind the structure to nourish the new mangrove forest nursery".
Mr Morris said the use of wood also provides a crucial organic surface for beneficial bacteria to live. These bacteria remove excess nutrients from the waterways.
"The structure also provides habitat for a range of aquatic life including many fish species that are sought after by recreational fishers," Shaun said. "In the coming months we will work with the local community to collect and place mangrove seeds into the nursery to speed up the growth of the mangrove forest," Mr Morris said.
Transport NSW installed three 'go slow' signage buoys to help remind boat users of the need to minimise wave wash along this section of Emigrant Creek as the mangrove forest matures.
To ensure the protection of any cultural heritage artefacts, Jali Local Aboriginal Land Council was brought in during the construction of the mangrove forest nursery area. These works form part of North Coast Local Land Services Marine Estate Management Strategy project, funded by the NSW Government and complement previous efforts of the Local Land Services in Emigrant Creek Catchment.
It is estimated that both stages of works will prevent more than 870 tonnes of sediment being lost annually from unstable riverbanks within the catchment.