DEVELOPMENT OF A DEMAND MODELLER AND TRACKING TOOL: TO ENGAGE LAND USE PLANNING AUTHORITIES IN THE OPTIMISATION OF WATER SUPPLY
AND SEWERAGE NETWORKS
Chris Teitzel 1, Ken Goraya
1, Partha Susarla
1
1. Unitywater, QLD, Australia
HIGHLIGHTS
An unique and innovative tool developed by Unitywater for forecasting and tracking capacity in the water
supply and sewage networks
The tool can be used by town planners to identify spare capacity for development
The tool can be implemented and configured for any utility or authority in any State or Territory
Currently being implemented by Unitywater across its service area. (Sunshine Coast, Moreton Bay
Regional Councils and Noosa Shire Councils).
INTRODUCTION
Unitywater operates in one of the fastest developing regions in Australia. The population of the region is
expected to grow by 63% in next 25 years. To meet the requirements of this challenge of projected growth,
Unitywater must be smart in developing tools for strategic planning to support the efficient delivery of network
infrastructure.
The basis for long term infrastructure (master) planning is the underlying growth assumptions that forecast
population and non residential demand. The development of demand forecasts to support infrastructure
planning is a highly complex process that requires collaboration between town planners, network planners
and planning engineers. Many utilities use manual procedures and ad-hoc approaches to prepare demand
projections which are time consuming, have poor transparency which results in inconsistencies. In the faster
developing regions such as Unitywater’s service area, growth assumptions change from year to year based
upon prevailing economic conditions.
The key drivers for the development of Unitywater’s Demand Modeller and Tracking Tool (DMaTT) are
increasing the efficient utilisation of network assets by identifying the efficient sequence of development and
where spare exists to serve new development. There is also a need for a credible and repeatable tool that
could model network demand associated with population growth, changes in land use and approved
development to inform “prudent and efficient cost” decision making in capital works planning.
METHODOLOGY
The purpose of the demand modeller and tracking tool (DMaTT) project is to develop and implement an
automated demand modelling, forecasting and tracking tool at Unitywater that is credible, consistent,
transparent and repeatable. The project was initiated in 2012 and was developed in-house with the
assistance of software vendor “Sizztech” and was deployed in early 2014. The DMaTT tool allows
forecasting of future demand and planning for the provision of water supply and sewerage infrastructure to
support future growth in a sustainable manner. The DMaTT tool has the ability to prepare baseline projected
and ultimate development data for dwellings, population, floor space, employment and network demand
(Equivalent Person, Equivalent Tenement or any other demand unit) at a property level that can be
summarised and displayed at any catchment scale (i.e. locality or water supply catchment).
The tool was developed in “.Net” platform and has ability to prepare forecast models through a live website
interface linked to GIS spatial databases. The DMaTT website interface allows forecast models to be
configured, run, exported and reconfigured at any time with three main modules:
Forecast Model Builder: building and configuration of forecast models (see Figure 1)
Forecast Model Viewer: viewing and comparing forecast model demand at a catchment scale (see
Figure 2)
Forecast Demand Viewer: viewing GIS layers and forecast model demand at a property level by
planning and development assessment staff (see Figure 3)
The key spatial information inputs into DMaTT forecast models include baseline land use, development
approvals, development constraints, planning scheme density provisions and state government long term
population growth projections sourced from Local Councils. Figure 4 is a graphical representation of how the
DMaTT tool constructs forecast models.
A key innovation of the DMaTT tool is the use of Bayesian Network (BN) for predicting the sequence of
development and growth. A BN is used to score each property against a range of criteria (e.g. land vacancy,
development approval, commercial viability and proximity to trunk infrastructure). The higher the combined
score (which is known as development desirability index) the more likely development is to occur. Growth is
automatically allocated to properties with the highest development desirability index until the catchment
population/floor space for each cohort is reached. The BN can be amended or reconfigured at any time and
loaded into the DMaTT website interface for the reprocessing of forecast models.
DMaTT also has the ability to run more than one forecast model based on “what if” scenario with changed
growth parameters. These scenarios can be compared to understand the impact of demand distribution.
This is very useful in understanding the impact of a new development front on the previous infrastructure
planned and hence provides information for just in time delivery of the capital works program. For network
modellers and consultants, the DMaTT website interface has an export function where adopted forecast
model demand at a property level can be exported for linking to external GIS property layers and network
models. An example is shown in Figure 5.
CONCLUSION
DMaTT is currently being implemented by Unitywater to forecast growth and manage demand across
Sunshine Coast, Moreton Bay Regional Councils and Noosa Shire Council areas. Forecast models
developed using DMaTT will inform new network master planning and a revised capital works program.
DMaTT can be used for the generation of dwelling, population, floor space (GFA), employment and network
demand projections. DMaTT will also be used by Unitywater development assessment staff for assessment
of water supply and sewer connection applications. An exciting outcome from the project is that users who
could benefit from the DMaTT tool extend well beyond Unitywater. The DMaTT tool can be implemented and
configured for any utility or authority in any state or territory that use an ArcGIS platform.
Figure 1: DMaTT Model Builder interface
Figure 2: DMaTT Model Viewer interface
Figure 3: DMaTT Demand Viewer interface
Figure 4: DMaTT Demand Viewer interface – property demand projections
Figure 4: Graphical representation of DMaTT Forecast Models
Figure 5: DMaTT Forecast Models Export function