top of page

Resources

The 5 hidden costs to Victorian councils of getting growth forecasts wrong

  • Team Forecaz
  • Jul 17
  • 8 min read

Missed revenue, mistimed projects, and legal risk: what weak growth data costs Victorian council.


Councils in Victoria's growth areas are planning new suburbs and increasing density in existing suburbs at record pace. On top of this they are navigating Housing Statement growth targets, accelerating Precinct Structure Plans (PSP) reviews, and Infrastructure Contributions Plan (ICP) scrutiny simultaneously. To do this well, they rely on a growth model: a forecast of where homes will be built, how many, and when.


When a growth forecast is wrong, the costs show up everywhere:


  • Get the order of development wrong and developer contributions arrive late.

  • Get the housing numbers wrong and roads and community centres get built too early or too late.

  • Get the demand forecast wrong and your grant applications fall short.


The first article in this series - Infrastructure Contributions Plan numbers can be a liability or a defence set the scene for councils managing ICP obligations.


This second article addresses a different question - what does a weak evidence base cost your council? The answer has five concrete parts, and for a fast-growing council the combined value at stake runs into the millions of dollars across each ICP cycle.


A KEY INSIGHT

Yes, an in-house model saves you consultant fees. External growth modelling studies typically cost between $75,000 and $200,000 each. But the fee saving is the least important number. The five costs below dwarf the saving, and none of them appears on an invoice.


Cost 1: Developer money you never collect 

Your council's ICP revenue depends directly on the accuracy of your development assumptions: which land develops first, how many homes go on each site, and in which year. When reality diverges from those assumptions, your contributions fall short.


The Municipal Association of Victoria (MAV) submission to Victoria's infrastructure contributions reform process documents the scale of funding behind current ICPs across Melbourne's greenfield growth councils, and the funding shortfalls councils already carry [1].


Outdated assumptions fail in two ways:

  • Under-collection. Development happens earlier or at higher density than assumed, and the charge schedule does not capture the full contribution the planning scheme entitles the council to recover.

  • A timing mismatch. Development follows a different order than projected, the money arrives later than the capital works bills, and the council funds the gap from other sources.


Growth area councils have had to fund infrastructure ahead of the contributions that area meant to pay for the work, carrying interim deficits on their balance sheets. For a fast-growing council such as Casey or Wyndham, even a modest improvement in revenue capture across a single precinct, on a funding pool measured in hundreds of millions, returns many multiples of the annual cost of the modelling platform behind the improvement.


Cost 2: Building things at the wrong time

Once infrastructure is built, there is no undo button:

  • A community centre built two years before the residents arrive carries running costs without the ratepayers to fund them.

  • A road upgrade triggered by a slow-moving development ties up money the council needed elsewhere.


The mechanism is simple. The capital works program follows the growth forecast. If the forecast is wrong, the building program is wrong too.


The margin for error is narrow. Australian Bureau of Statistics (ABS) figures for 2023-24 record Melton as the fastest-growing council area in Australia, with Wyndham consistently ranking among the largest population increases in the country [2][3].


The National Growth Areas Alliance (NGAA) has documented residents of outer suburbs receiving among the lowest access to social infrastructure of any community type in Australia, with Victoria recording some of the largest gaps [4][5]. This is partly a funding problem. This is also a timing problem. Councils able to time their capital works against a realistic, site-by-site forecast, updated as approvals and construction starts coming in, makes materially better use of the funding they have.

THE COMPOUNDING EFFECT:

A growth model updated continuously, rather than rebuilt every few years, makes accurate timing possible. The difference compounds with every delivery decision made between reviews.


Cost 3: Legal challenges you struggle to defend

Developers have legal standing to contest infrastructure charges. Challenges are not common. They are also not rare, and a challenge gaining traction typically attacks the growth assumptions underneath the charges: the housing yield estimates, the development order, and the demand rates applied to infrastructure networks.


An ICP built on assumptions no one has updated since the plan was approved is far more exposed than one backed by a live model with a clear audit trail. Defending a challenge costs legal fees, expert witnesses, staff time, and the reputational hit of having your assumptions publicly tested. For a contested matter, the total runs into hundreds of thousands of dollars. A successful challenge forces the council to amend the ICP, and signals to the development industry your charges are contestable. 


THE DEFENSIVE POSITION

A Machine Learning (ML) generated, property-by-property growth model with version-controlled inputs and auditable outputs is materially harder to challenge than a consultant spreadsheet produced once and never maintained.


Cost 4: Grants you miss out on


State and federal grant programs increasingly require evidence-based demand forecasts as a condition of applying, with application windows measured in weeks, not months.


The Growth Areas Infrastructure Contribution (GAIC) program shows the scale. As at 30 June 2025, GAIC had collected $1.49 billion in cash contributions across Melbourne's seven growth area councils, and had funded 156 infrastructure projects worth $1.2 billion [6]. The most recent funding round, opened on 20 December 2024, made up to $150 million available, and applications closed about ten weeks later [6][7].


A council with an in-house growth model produces a demand forecast for a specific corridor or service area in hours. A council relying on external modelling either commissions a study on short notice at premium cost, submits a weaker application than its growth profile warrants, or misses the round entirely. Missed grants appear on no budget line. They are invisible losses, and they compound over time.


Cost 5: Planning reviews stuck in a queue


Victorian councils must review their planning schemes regularly. Without an in-house model, each review touching growth assumptions triggers a new consultant engagement, which must be scoped, procured, and delivered. By the time it is complete, some of the inputs have moved.


With a live in-house model, a review runs faster because the model already exists. Housing Statement density targets, PSP amendments, Activity Centre re-zonings, and affordable housing settings are all re-tested within the existing model rather than rebuilt from scratch each time. For councils juggling several of these at once, this re-testing work is continuous, not occasional. The difference between in-house capability and periodic consultant delivery is the difference between a planning team responding to change and one always catching up to change.


Putting the numbers together


The five costs above do not all land at once, and not every council will face everyone. However, for a fast-growing council with active ICPs across multiple precincts, a pipeline of tens of thousands of homes, and an infrastructure program in the hundreds of millions, the combined exposure is significant.

THE COST COMPARISON WORTH MAKING:

Not the cost of a Forecaz VIC subscription against a single consultant study. The cost of the platform against the combined value of the five failure modes above: revenue not collected, works mistimed, challenges not defended, grants not won, reviews not finished on time.

This changes the decision from "should we fund a growth forecasting tool?" to "should we fund going without one?"

What Queensland councils demonstrate

The clearest evidence comes from Queensland, where councils face structurally identical challenges:

  • big infrastructure programs

  • growth assumptions required to hold up under scrutiny, and

  • planning teams without the resources and budget to rebuild their evidence base every time policy moves.


See the case studies below:

  • Major Queensland regional city

  • Comparable to Victoria's regional cities

Toowoomba Regional Council (TRC) manages a major regional city alongside established suburbs, new growth fronts, and a large rural hinterland.


The planning challenges are directly comparable to Greater Geelong, Ballarat, Greater Bendigo, and Greater Shepparton. Forecaz models residential, commercial, and employment growth across the whole council area, giving the planning team a live evidence base for capital works planning, scheme reviews, and grant submissions without a new consultant study for each one.


Forecaz models residential, commercial, and employment growth across the full TRC council, giving the planning team a live evidence base that supports capital works planning, planning scheme reviews, and grant submissions without relying on periodic consultant engagements for each requirement.

Victorian analogues:  Greater Geelong, Ballarat, Greater Bendigo, Greater Shepparton, Latrobe City

  • High-growth corridor

  • Comparable to Melbourne's growth area councils

The City of Moreton Bay (formerly Moreton Bay Regional Council) is one of Queensland's fastest-growing councils


It manages the same mix of new growth corridors and established suburbs found in Wyndham, Casey, Melton, Whittlesea, and Hume: growth at scale, several active precincts, and delivery programs in the hundreds of millions.


Forecaz handles both the new-suburb sequencing and the established-area complexity in a single platform.

Victorian analogues:  Wyndham, Casey, Melton, Hume, Whittlesea

  • Large metropolitan scale

  • Australia's second-largest council by population

The City of Gold Coast has an estimated resident population of about 681,000 (ABS, June 2024) and is Australia's second-largest council area by population after Brisbane City Council.


The council uses Forecaz as the modelling platform for its full Local Government Infrastructure Plan (LGIP) evidence base [9]. The Queensland LGIP is the direct equivalent of Victoria's ICP system: site-by-site growth forecasts underpinning infrastructure scheduling and charges.

Victorian analogues:  Casey and Wyndham (scale and LGIP-to-ICP equivalence)


Reported outcomes from Forecaz deployments in Qld


Figures are indicative benchmarks. Actual outcomes for Victorian councils depend on starting data quality and council profile. Independent verification is recommended before using these figures in internal business cases.

Outcome

Before Forecaz

With Forecaz

Data cleansing for a new model 

Up to 18 months 

Reduced to approx. 6 months 

Demand forecasting cycle 

6 to 9 months 

5 to 7 days 

Scenario comparison for decisions 

Commission new study (weeks) 

Internal run (hours to days) 

Evidence base between ICP reviews 

Static; periodic rebuild 

Live; continuously updated 


Making the Forecaz VIC business case internally

For a Director of Planning presenting the case for Forecaz VIC to a CEO or council, the strongest framing is not the consultant saving, even though it is the most visible number.


The strongest framing is the compound effect across all five costs, applied to the specific scale of your council's infrastructure program.


The value at stake is not the annual subscription. The value at stake is the sum of avoided costs, recovered revenue, and compressed timelines over the life of the platform.

The next article in this series, due out soon, goes deeper into the Toowoomba experience and translates the outcomes for Victorian regional cities at comparable scale.



Arrange a Forecaz VIC discovery session for your LGA

A 30-minute discovery session for your council area. See the full ROI case applied to your LGA's growth profile before any commitment.

Call Annette Henry (0418 123 133), Bradley Rasmussen (0419 738 378) or book below:




References:

2.     Australian Bureau of Statistics, Regional Population, 2023-24 financial year.

3.     .id (informed decisions), Population growth and decline by LGA in 2024.

6.     Planning Victoria, Growth areas infrastructure contributions (GAIC collections and funded projects as at 30 June 2025).

7.     Premier of Victoria, More Infrastructure Where Homes Are Getting Built, 20 December 2024.

9.     Engineering for Public Works (IPWEA-QNT), Issue 23, page 44.


Legal Disclaimer:

This article discusses the commercial and operational consequences of weak growth evidence bases for Victorian growth area councils based on publicly available information. It does not constitute legal, financial, or planning advice. Specific figures cited are sourced from public documents as attributed. MAV-sourced ICP figures are indicative and should be verified against current ICP schedules before external publication. ABS population figures cited refer to data published in the ABS Regional Population series; readers should verify specific figures directly from the ABS data cube. Forecaz-reported outcomes from Queensland deployments are indicative benchmarks only; independent verification is recommended. Councils should seek independent legal, planning, and financial advice about their specific obligations and circumstances. Forecaz recommends that councils review all applicable guidance from the Department of Transport and Planning and the Victorian Planning Authority.




RESOURCES
bottom of page