Rock fillets are constructed adjacent to eroding estuary banks for stabilisation. Rock fillets are energy dissipating structures, which are typically built to mean high water level from locally quarried rock, although fillets may also contain other habitat enhancement structures such as timber snags, or prefabricated reef balls. The fillets are a bank parallel structure, keyed into the bank at one end and open at the other, creating an area of low hydrodynamic energy in the intertidal zone between the fillet and the bank. This area of still water encourages sediment accumulation, and the regeneration of mangroves and other estuarine vegetation, where the mangrove propagules, fish and other estuarine fauna can pass through the fillet opening.

Mangroves

Method: Hybrid, Planting

Mangrove species: Avicennia marina

Planting density: 1/m2

Hybrid structure: Rock fillet

Hybrid structure height (m): Changes relative to bed level. Top of fillet is built to 200mm above mean high water at this location

Hybrid structure width (m): 2m base

Hybrid structure length (m): 20m