Works Map Key Descriptions
Stormwater Treatment Facilities

Sediments and nutrients carried by stormwater runoff can impact greatly on Lake water quality and ecosystem health.

Stormwater Treatment Facilities aim to reduce the impact of sediment and nutrients by mimicking natural systems and are a preferred alternative to traditional concrete drainage lines. 

There are different types of Stormwater Treatment Facilities including:

  • Constructed wetlands
  • Detention basins
  • Sediment or silt traps
  • Gross pollutant traps
  • Vegetated swales
  • Riffle ponds
Foreshore Stabilisation / Vegetation

Foreshore and creek banks form a key part of the Lake’s estuarine environment.  These areas provide recreation opportunities for residents and important habitat for wildlife.  Residential development along creek fronts and foreshore land can result in a loss of native vegetation, accelerated bank erosion, and increased volumes of runoff containing sediment and nutrients.

Revegetation of foreshores and creek banks are accompanied by many different stabilisation techniques including the use of rock and small pebbles, and reshaping the foreshore/creek bank to a natural sloping beach.  The use of small pebbles along the natural sloping beach allows dead seagrass wrack to wash out of the water and decompose naturally.

Maintenance Dredging
Maintenance dredging is the dredging or removal of bed sediments to return the area to a similar level to what previously existed. It refers primarily to the removal of delta plumes or fans at the end of stormwater lines entering the Lake. This accumulation of sediment smothers and prevents seagrasses from growing. It can also refer to the dredging of shoals in the main navigation channel.
Wetland Rehabilitation

Wetlands are an important part of the aquatic ecosystem as they provide a natural filter system for our water, trap sediment and decrease nutrients and pollutant from entering Lake Macquarie and provide habitat, protection and important nursery areas for aquatic animals.

Wetlands are amongst the most threatened ecosystems.  Around 35% of Lake Macquarie’s wetlands have been lost and 70% of Lake Macquarie wetlands have been found to have reduced in size over the last five years.

Wetland rehabilitation undertaken by the Office of the Lake Macquarie and Catchment Coordinator has involved weeding, planting and bush regeneration, along with rubbish removal, fencing and signage.  Lake Macquarie wetlands that have been rehabilitated include:

  • Boat Harbour Wetland, Silverwater
  • Pelican Wetland, Pelican
  • Beauty Point Wetland, Dora Creek
  • Galgabba Point wetland, Swansea
Nearshore Organic Sediment Removal and Foreshore Improvement

Many shallow embayments around Lake Macquarie contain vast seagrass beds.  While these seagrasses provide enormous value to the ecology of the lake, they can cause problems around the foreshore when the plants shed their leaves or fronds.  The fronds typically wash up onto naturally sloping foreshore as wrack, where it then decomposes rapidly.

Where vertical seawalls or escarpments have replaced most of the naturally sloping foreshore, the seagrass wrack accumulates and breaks down underwater to form oozy organic sediment.

The aim of Nearshore Organic Sediment Removal and Foreshore Improvement is to enhance the natural lake processes occurring around the shore and provide a better environment for all.  The works involve the removal of nearshore organic sediment using an excavator, followed by the placement of sand and/or cobble to re-establish a gently sloping beach foreshore to reduce the likelihood of the organic sediments returning in the future as seagrass wrack can to wash up on the shore and decompose naturally.

 

Lake Macquarie Works Map
 
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