The TREENET Local Government Street Tree Practice survey was originally designed as a tool for determining the areas in which TREENET can offer the most assistance.  Without a concrete idea of the issues facing individual Councils and their street tree programs, it isn’t possible to tailor our services in the most useful way.

With the recent release of the new Local Government Act (1999), a significant responsibility has been placed on Local Councils with regard to their trees.  Section 232 of the Act specifies that it is an offense for any tree to be planted in a street without the approval of Council, and that tree planting must take into consideration the potential impacts, responsibilities and amenity of the street.

Section 245 of the Act also places property damage liability on Councils for trees which they have been notified are a hazard.  In the light of these Sections, it is now critical for Councils to assess their street tree practices to ensure that the risk of litigation is minimised.

In light of these issues, it is not surprising the response to the survey was so good; of the 68 Councils coming under the Local Government Act in South Australia, 65 agreed to complete the survey, and 33 actually responded.

The survey will be redesigned for future use taking into account the feedback given by respondents, so that it can better represent the responding Council in an unambiguous way.  Eventually, the survey will be available in electronic format on the upcoming TREENET website, so that it can be easily accessed and submitted.  As TREENET expands into the national arena, it will be open to more than 700 Councils to respond, so an efficient delivery system and clear questions are critical.

Any suggestions, not just from Councils, on how to improve this survey would be of immense use.

To complement the Local Council survey, we hope to develop similar surveys for the other areas TREENET will interact with, such as Nurseries, Arborists, Landscape Architects, Urban Planners and Tree Training providers.  Information given to TREENET in all of these surveys should be considered public domain information; we want to give free access to as much of the resources we have as possible.  Part of the goal of TREENET is to provide a central place where everyone can come to find out how best to approach a street tree issue, and learning from the examples and mistakes of others is a useful process.

So, as far as the survey is concerned, it showed us some things we expected, and quite a few surprises.


The people who are making both day-to-day and strategic management decisions about Local Government street tree practices can benefit most by receiving the right training.  All the advice in the world will not help if the person involved in the process does not see its value.  TREENET can assist in bringing the latest research and collaborations to the attention of the training providers so that Councils can make their improvements from the ground up.

The most common qualification was the Advanced Certificate in Horticulture, with 14 respondents, followed by the Diploma or Advanced Diploma in Horticulture.  The responses also indicated that staff training represented in the Council or planned for the near future was primarily sourced from the TAFE system.  As a vocationally oriented educational provider the TAFE system offers the skills and training that will allow Councils to maximise the value of their street tree assets.  Private providers of training are also a regularly used resource


The average annual budget for street tree expenditure is just over $200,000 per Council, with the least being none at all for several regional Councils.  In these cases, the street tree system was either practically non-existent or entirely dependent on volunteers.  The largest was almost 1.3 million dollars a year for a Council with 80,000 street trees and 25 full time staff.  The majority of Councils have a stable budget allocation for street trees, most others are receiving more money to manage their trees each year.  Each Council averages 20,000 trees, or (very roughly) one tree per resident, representing 30 different species of tree. Over 1000 trees are planted per year.

During the first three years of a street tree’s life, Council will spend approximately $220 on the tree, although some Councils may spend up to $650. The mortality rate amongst these trees is 12% (with some Councils going as high as 40%!). So more than 10% of a Council’s new planting budget goes into dead trees.  If this figure was to change by only one percent, it would mean considerable savings for Councils.

65% of respondents believed their budget was adequate to their needs;  35% believed it was inadequate.  Nobody thought their budget was excessive.

10% of budgets are set aside for contract work, and another 2% for education and training.

So, as far as the investment in street trees is concerned, making the wrong decisions about which tree to plant is a decision that can cost hundreds of dollars per tree. Making a few changes in the techniques used during the three years can not only save hundreds of dollars and trees over this period, but can increase the useful lifespan of the tree and save money in replacement costs.

Success Factors

Every factor mentioned in the survey was deemed important to the overall success of a planting program;

  • Information on suitable species
  • Availability and quality of nursery stock
  • Difficult site conditions
  • Funding
  • Human resources
  • Specialist knowledge
  • Vandalism


TREENET aims to be in the position to help with these factors.  Information on species suitability will be determined through the trial site program and gathering of relevant research material in consultation with tree experts.

Nursery stock can be diversified as individual nurseries take on trees which have been shown, through trials and other information, to be in demand for street use.

Addressing the difficulties of poor site conditions can be part of the development of best-practice planting and maintenance models devised in conjunction with arborists and soil specialists.

In terms of funding, TREENET can assist Councils in the development of trial sites by, for example, collaborating to identify and submit grant applications to appropriate funding bodies.  An example of this for regional Councils is the Department of Transport’s Regional Solutions program, which offers up to $500K for regional projects.  TREENET, in association with a group of regional Councils, might prepare an application on their behalf to establish sites throughout the region.

Through its network of over 200 contacts, TREENET can find and refer specialists to a Council for assistance with difficult projects.

One of the interesting results in this survey was that of the 33 people who responded, only 2 said they were happy with the street tree program they had inherited from their predecessor.  More than 60% were actively disappointed with the trees they became responsible for, with the most common complaints being infrastructure damage, high maintenance, incorrect cultivation requirements and liability risk.

These figures are very telling: when the people currently involved in street tree management come to hand over the reins, what will their successors think of the situation they’ve been given?  There is an obvious recognition of the failure in the past to do the right thing with respect to street trees, but this recognition needs to be supported with the resources to make a difference.  If TREENET can offer the information and opportunity to change this figure, we’ll have done very well.

Personal Injury & Property Damage

Far and away the most significant cause of injury and damage comes from displacement of kerbs, paving and roadways by tree roots.  This is probably no surprise, but it reinforces the necessity to diversify street tree species into low-impact root systems.  The presentation by Tim Johnson of the City of West Torrens details that Councils’ experience with a range of newly trialed species.

Tree Inventories & Databases

Half of the responses indicated that the Council did not have an inventory of their street trees.  Interestingly, in 1998 the Australian Local Government Association required all Councils to conduct a measurement of their assets, including street trees, so technically every Council in Australia should have a record of this.  This result indicates that either some Councils simply don’t have the resources to conduct such a measurement, or that the information gathered in that process is not widely available or recognised within the Council.  In either case, greater support for Council projects such as this is obviously required.

TREENET aims to provide to Council street tree departments as comprehensive and convincing a list as possible of reasons why their Council should support their tree improvement programs.

Tree stock

Almost every Council sources some of their tree stock from South Australian Nurseries, and for many of them this is the primary source.  Half draw upon their own nursery facilities for some component of their new plantings, and one third draw stock from interstate.  Most of this stock is container grown, with a smaller portion being simple bare root stock.

Future Surveys

In order to fully develop TREENET as a relevant and worthwhile resource, the broader stakeholder groups contributing to Street Tree issues will be surveyed and assessed.

We welcome any contributions, suggestions or feedback for this process, because it is by accessing the experience and knowledge already available that can make the TREENET program an effective and efficient resource.

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