Waterways

​Waterway rehabilitation refers to the planning, preventative and intervention measures protecting the health of our waterways and their surrounds.

Urban development places significant pressure on waterways and their environmental and social value. The increased flow and frequency of urban stormwater can be a significant force in stream erosion and subsequent sediment generation. In addition, stormwater contains significant levels of contaminants and pollutants which can further degrade the waterway health.

This section provides planning and works advice associated with the protection and rehabilitation of waterways as part of the land development process. The Technical Guidelines for Waterway Management 2007 should be consulted for key design principles.

Technical Guidelines for Waterway Management 2007

Waterway protection

Objectives and principles

The following objectives and principles:

  • protect the natural morphology of the stream and its associated landscape form and values (e.g. natural escarpment areas and valley form to natural break of slope)

  • protect remnant flora and fauna values along the waterway corridor

  • protect archaeological heritage sites along the waterway corridor

Planning considerations

The following provides considerations to improve the waterway interface with open space:

  • undertake studies to assess impacts of present and future stream flows, waterway form and bed and bank condition, any significant geomorphological features and appropriate measures to rehabilitate the stream in a context of increased impacts from urbanisation

  • undertake surveys to assess archaeological, flora and fauna values along the waterway reserve adjacent to the development site and plan for their protection

  • when modifying natural waterways or designing modified waterways to mimic natural waterways, attempt to retain the local waterway character by incorporating geomorphic elements of local waterway types

  • plan revegetation of the riparian zone to create a diverse and robust vegetated environment compatible with the original Ecological Vegetation Class (EVC) and the local waterway character

Cultural and heritage assets

From 2007, Aboriginal cultural heritage is protected through the Aboriginal Heritage Act and the Aboriginal Heritage Regulations 2007.

Further information

Aboriginal Heritage Act 2006 and Aboriginal Affairs Victoria

Heritage Act 1995

Bed and bank stabilisation

Through the impact of increased flows and removal of riparian vegetation the bed and banks of waterways can become highly susceptible to erosion. This may result in increased turbidity, smothering in-stream vegetation and ultimately increasing sediment loads in Port Phillip and Western Port.

Increased erosion also undermines remnant indigenous vegetation in adjoining parkland and threatens assets such as bridges and path systems. The best approach is to reduce the impact of urbanisation through on-site measures such as Water Sensitive Urban Design (WSUD), but where necessary direct intervention can be used.

Objectives and principles

The following objectives and principles:

  • provide soft engineering solutions to prevent further erosion of the waterway

  • design a treatment system that is sympathetic to the waterway environment

Planning consideration

Bank battering

Bank Battering involves the modification of the stream bank to provide a stable surface which aids the establishment of vegetation. Bank battering can be used to accelerate the rate of recovery from past channel incision, or to increase the safety of a steep bank in an urban environment.

Bed stabilisation

Grade stabilisation is generally implemented to halt an ongoing incision process, increasing stream stability and stream health in the vicinity of the incision, as well as helping to protect upstream assets from incision and reducing downstream sediment supply and deposition.

Rock chutes

Rock Chutes are also known as rock riffles and rock ramps. They generally involve the excavation of the bed and banks of a stream and the placement of quarried rock on the bed or banks on a slope steeper than the natural stream to create a graded weir. Rock chutes are largely constructed to control the gradient of stream beds, however they can be used to address other stream management issues such as  provision of fish passage, diversion weirs, sediment stabilisation and the creation of riffle and pool habitat.

Rock groynes

Rock Groynes are largely impermeable deflectors placed into stream systems to prevent bank erosion, create deposition and alter the local plan form of the stream. Rock groynes provide some erosion protection and result in a small scale deposition.

Rock beaching

Rock beaching involves the placement of quarried rock (rip rap) on stream banks. The rock is founded on the bed of the stream and generally extends up the portion of the bank threatened by erosion. This technique provides localised protection only and doesn't address system wide processes.

 

Last updated:
27 September 2017