Part C: Swansea Channel

Defining features of Swansea Channel

• Connects main body of Lake Macquarie to the ocean

• Broadly divided in two at Swansea Bridge, which carries traffic across the channel and connects

Blacksmiths and Swansea – see Figure 10

• Downstream impacted by oceanic swell waves

• Upstream, dominant coastal processes relate to tidal currents and transport of sediment

• Increased flow velocity and scour upstream resulting in failure of foreshore protection works

• Rapid shoaling upstream of the entrance to

Swan Bay • Highly modified entrance with training walls constructed in the 1890s

• Waves downstream of bridge, tidal currents and upstream transport of sand have caused erosion

• Significant erosion in Salts Bay and between Mats

Point and entrance to Black Neds Bay

• Important shallow seagrass habitats for fish breeding and migratory birds, particularly from

Belmont through to Swansea Flats

• Variable tidal range, decreasing from 1.7m at the entrance, 1.3m at Swansea bridge to less than 0.2m at the western end of the channel

Swansea Heads and Blacksmiths

Figure 10: Key locations in Swansea Channel

Key management issues and challenges for Swansea Channel

• Differing objectives regarding the use, funding and ecological health of Swansea Channel • Defining responsibilities for dredging, foreshore works and maintenance of coastal protection assets

• Effective management of hydrodynamic processes to achieve appropriate long-term management • Channel depth can impact the boating recreation sector and opportunities for the lake to become a significant tourism destination • Impacts of training walls • Dynamic nature of channel form, especially foreshore erosion

• Repeated dredging and works such as partial

closure of southern entrance to Swan Bay over the past decade as part of channel management • Channel evolution – channel gradually changing over time

• Vulnerability of the suburbs surrounding the channel to inundation

• Competing needs of multiple stakeholders and finite funding • Impacts of tides and waves, combined with future sea level rise

• Dynamic nature, presents challenges for integrated management • Structures, such as Swansea Bridge, bank protection works, dredge spoil islands and extensive works at the entrance to Swan Bay have contributed to modified hydrodynamic conditions and channel characteristics

SECTION 3 -

COASTAL ZONE RISKS AND HAZARDS