Unitywater Noosa Netserv Plan - Planning Assumptions · Attachment 1 - Draft Technical Note on Noosa Shire Netserv Plan Planning Assumptions

                                                       l   Noosa Netserv Plan Planning Assumptions June 2024




4. Forecast Model Scenario Testing and Validation
A key function of the DMaTT tool is the ability to run a forecast model with different growth
projections, development densities and timing of development within future development
areas. The NSC model has been developed through an iterative process of developing and
configuring of growth projections, development densities and the timing of development
assumptions, running the model and reviewing and testing the model outputs.

Each model export is reviewed to validate that forecast growth and the forecast sequence of
development is reasonable and credible having regard to the:
    • timely incorporation of current and approved development;
    • calculated development yield (based upon development densities and constraint
        assumptions) is consistent with similar approved development;
    • utilisation of vacant infill and greenfield land supply;
    • available development capacity (ultimate development) of land within a population or
        GFA projection catchment to accommodate forecast growth;
    • realistic availability of development capacity to guide growth projections (i.e. in infill
        areas, looking at realistically available capacity on vacant land or land substantially
        undeveloped such as having a detached house or outbuilding, excluding capacity on
        properties with existing attached dwellings and non-residential); and
    • propensity for development of land and the associated forecast sequence of
        development.
Subsequent amendments are then made growth projections, development densities and the
timing of development assumptions and run within a new forecast model. The process is
then repeated until forecast growth and the forecast sequence of development is reasonable
and credible having regard to the above. Typical examples of scenario testing resulting in
amendments to population or GFA projections include:
    • where newly created vacant residential or non-residential lots (where there is
        evidence that new dwellings or non-residential buildings are being constructed) are
        not sequenced for development and require an increase to the population or GFA
        projections to accommodate growth and redistribution of growth from another
        typically adjoining catchment where possible;
    • development approvals commencing within its currency period resulting in forecast
        growth that exceeds population or GFA projections and require an increase to the
        population or GFA projections to accommodate approved development and
        redistribution of growth from another typically adjoining catchment where possible;
    • population or GFA projections exceed the available development capacity of land
        within a catchment and require a decrease in population or GFA projections and
        redistribution of growth to another typically adjoining catchment where possible; or
    • forecast development is occurring on properties with a low propensity for
        development or exceeds realistic availability of development. This is typically
        represented by the forecast sequence of development on properties which are
        already substantially developed and have marginal capacity for further development
        and require a decrease in population or GFA projections and redistribution of growth
        to another typically adjoining catchment where possible.




                                                                                                      25