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