This node is generally used to represent roof areas for any building including sheds and car ports.
Roof nodes can only be modelled as 100% impervious in accordance with NSW, QLD, VIC & SA guidelines.
In QLD, the pollution generation from roofs is dependent on the development type (industrial/commercial/residential).
For all other locations, the pollution generation for roofs is independent of development type.
In VIC, this node should only be used to model non-trafficable roofs.
For modelling trafficable roofs (eg: terraces and balconies) in VIC, see “Road, Sealed Road, Balcony, Terraces, Footpath” section.
This node is generally used to represent paved areas such as carparks, roads and pathways.
In VIC, this node is also used to represent trafficable roof areas such as balconies & terraces.
In QLD, the pollution generation from road is dependent on the development type (industrial/commercial/residential).
For VIC, road areas have to be modelled as 100% impervious.
For QLD, road areas can be modelled to include some percentage of pervious areas (eg: small landscape areas in carparks or verges on highway).
This node is only used in NSW regions since the NSW guidelines differentiate between pollution generation on sealed & unsealed road areas
In NSW, sealed and unsealed road areas can be modelled to include some percentage of pervious areas (eg: small landscape areas in carparks or verges on highway).
This node is generally used to model areas that are predominantly pervious such as urban landscaping & residential backyards.
In QLD, the pollution generation from Landscapes is dependent on the development type (industrial/commercial/residential).
For NSW, pervious areas are modelled using varying parameters depending on soil type (see “Soil Type” section).
These nodes appear for some authorities to enable backwards compatibility and allow Council to verify JCO models with Council’s MUSIC- link (details in image below).
This is due to a drawback in MUSIC-link (one of many), requiring Roof nodes to contain the correct soil type parameters for the location in order to verify them as compliant
However, soil parameters are only relevant if there is a percentage of pervious area in the node.
NSW MUSIC guidelines specify that Roof nodes must be modelled as 100% impervious, meaning soil parameters are irrelevant for verification of Roof nodes.
For NSW, pervious areas are modelled using varying soil type parameters as per each Authority’s guidelines (eg: clay, sandy loam, silty clay)
NSW MUSIC guideline requires soil type for modelling be identified based on topsoil (the top 0.5m layer of soil )
To identify appropriate topsoil type for modelling:
Engage geotechnical report/ services.
Consult Council engineer.
Estimate by going to NSWE-spade websiteand following steps in image on the below.
The separation between Roof, Road and Landscape has to do with the amount of pollutants these areas generate.
Generally, Roads generate far more pollutants than Roof, especially TSS (Total Suspended Solids).
Soil characteristics for 100% impervious areas do not matter, because the soil areas on which water falls is zero.
Soil parameters have an impact on how much water
is lost through infiltration in the soil.
is generated as “base” flows (cleaner water).
is generated as “storm” flows i.e. flowing overland.
Mixed catchment modelling (also known as lumped catchments in some regions) assumes pollution generation follows a typical Australian urban catchment
More suited to modelling larger catchments over 10ha & where the urban surface areas (roof, paved, ground) are difficult to identify.
