Work through the nine-step 3×3 framework — from asset register to a funded, monitored position — with service potential kept visible throughout. It opens in a new tab so you can keep the Guide alongside it, and your data stays in your browser.
How the model relates to the Guide
The Planning Model computes the Practice Guide’s method for urban trees, Steps 4 to 8:
- two loss rates by age — one for the first five years after planting, one after — and the Guide’s crown-growth curve;
- the planting that sustains the stock and the expansion rate, with the plantable-site check;
- cohort operating and maintenance costs;
- the GI Sustainability Ratio on the Guide’s strict basis, with OPEX Coverage beside it;
- the four planning scenarios.
Greendale Shire, the Guide’s worked example, opens from the model’s start screen (“Open the Guide’s Greendale example”), with the Guide’s inputs and the illustrative program, delivery capacity and funding split stated in Step 4 §4.9.
Where the model simplifies the Guide or adds to it, it says so on screen and in the report:
- Urban trees only. The model covers the urban trees class. It does not yet cover WSUD, green roofs and walls, or waterways, wetlands, bushland and coast.
- Two declared parameters are fixed. The crown-growth curve and the crown at planting are fixed at the Guide’s declared values. The two loss rates and the crown at age 20 are yours to enter.
- Scenario settings, not forecasts.
- Service-potential-led and Optimised Levers run at improved loss rates: both rates × 0.875, unless you enter your own pair with its evidence.
- Where BAU’s or the preferred scenario’s own ten-year OPEX Coverage is below 90%, a stress row raises both its loss rates by 27.5%. It is a stress case applied in proportion; no measured link between funding and survival lies behind it.
- Every scenario also shows a range: its program planting run again with both its loss rates scaled down and up by the ratios between the Guide’s defaults and the ends of the published ranges, so that on the defaults the range is 4.0–10.4% in the first five years and 1.5–3.8% after that. On other rates the ends move with them, and the report names any end with a rate outside those ranges. It gives the canopy at both ends, and the Status where that changes across the range. It varies losses only, not crown growth, so it is not a confidence interval and understates the uncertainty.
- Blank is not assumed. Where the age mix, the delivery capacity or the plantable sites are not entered, the model does not invent them. It says what each figure needs, or reports that limit as untested.
- Funding not split between sustain and expansion is counted against sustain first, each year up to what sustain needs that year. The report says where the ratio rests on that rule.
- Storm and reactive works entered with the cohort costs sit outside the GI Sustainability Ratio’s sustain requirement in this release, though they are in the full requirement; the Guide counts them within operations and maintenance (Step 8 §8.4). Storm works entered as an activity line are counted in the sustain requirement. The report notes them where they reach $50,000 over ten years.
Pilot release. The Planning Model is open to members as a pilot release. Its canopy method takes its loss rates and crown growth from published evidence, mostly from overseas, and has not yet been calibrated against Australian council records. Treat its canopy projections, and the planting numbers and costs the method sizes, as indicative. Before its general release, the method will be checked against a small number of councils’ own canopy and planting records.
How the canopy method was tested. The Guide’s canopy method was revised in October 2026, from published evidence: trees are lost at 7.0% a year in their first five years after planting and 2.5% a year after that, and crowns keep growing after age 20 (Step 4). We then tested it against canopy change measured on council land. On the City of Melbourne’s council land (2008–2016) it projected a rise of 5.6% where the surveys measured about 2%: close to the growth measured on streets, and above that in parks. On council land across metropolitan Adelaide (2018–19 to 2022) it projected a rise of 2.6% where the surveys measured 14% to 27%, part of which is probably survey difference or canopy that is not the council’s trees. The method it replaced projected a fall in both. Treat projections for mature, closed-canopy parkland, where crowns already touch, as an upper estimate, and check the trajectory against your own canopy records.
Canopy data: City of Melbourne and the Department for Environment and Water, South Australia, both CC BY 4.0. The data has been analysed by the Landscape Foundation of Australia; neither body endorses this analysis.
Use the report as building blocks for your AMP, and check its figures against your own records.
Checked against the model released October 2026.