This is a paper that was formally received by Burnside Council (Adelaide, South Australia) on 17.9.02 recorded as Resolution C5944. It was posted on the internet for a time.
Discussion paper
"OPPORTUNITIES FOR TREES" : THE GREENING OF BURNSIDE
To speak in favour of a policy of "the greening of Burnside" may seem odd for a City renowned for its leafy, treed environment. It takes very little reflection, however, to realise how important it is to maintain and develop a policy framework with this in mind.
Urban consolidation (or urban regeneration as it is euphemistically and, to many locals, irritatingly referred to) has been firmly established. Whether it be seen as a laudable approach or merely as over-development, it is clear that it is to prevail in Adelaide. It matters little which government started it and a focus on who is to blame misses the point when looking at the practical consequences that must be addressed.
The benefits of urban consolidation are claimed to be many, including the containment of urban sprawl and the saving on infrastructure costs. The costs are also many, however, including:
1. increased noise resulting from closer living
2. increased power requirements for heating and cooling
3. increased pollution – eg, more cars per sq metre
4. increased usage of existing infrastructure (more cars; more people; more sewage; more water being used)
5. adverse effects on the environment and infrastructure resulting from the prevalent style of construction with hard paved surfaces, lack of lawns and garden areas, and preference for ornamental small plantings (roses, small shrubs, flowers) rather than larger tree plantings
6. increased incidence of flooding (as a result of 5 above)
7. loss of vegetation even when trees are replaced, due to the planting of smaller replacement trees or simply the time taken for replacement plantings to reach the size of trees that have been felled.
In addition, ageing infrastructure is not necessarily being maintained or replaced by water and sewerage authorities, so that the increased pressure on these assets may lead to more (and more serious) problems. If the savings resulting from the new services not now required for an expanding urban sprawl are not applied to maintenance and replacement programmes for existing ageing infrastructure, the benefits will be less and the costs greater than the cost/benefit analysis of urban consolidation policies would otherwise suggest. Pipes may burst sooner than they otherwise would have. The damage caused by this and the numbers of persons affected is likely to be far greater than they otherwise would have been.
Urban consolidation is a particularly attractive prospect for developers (whether they be one-off "personal superannuation fund" developers at the lower end of the scale or the professional developers at the upper end) in an area such as the City of Burnside, where the amenity level is high, land values are high and rising, and the location is and generally always has been regarded as among the most desirable in Adelaide. In addition, there are large blocks of land still in the hands of asset-rich, income-poor owners whose needs may include the conversion of some assets into cash and a declining ability to maintain a large property, perhaps coupled with an actual desire to move to smaller premises (whether nursing home, retirement village or smaller independent living).
Large trees (sometimes any trees) pose obstacles to the re-development of the built form on land. The removal of trees has been reined in somewhat as a result of the Significant Tree legislation. Protection for the trees at the smaller end of that protection (briefly – somewhat oversimplified – 1.5m to 2.5m diameter measured at 1m above ground; SA indigenous 4m or more high) is presently under review by State Government. It may not survive the end of 2002. The City of Burnside has a Significant Tree Plan Amendment Report out for public consultation at the moment, but its scope is minimal and many trees (perhaps thousands) of those dimensions may be unprotected after the end of 2002. Protection for trees at the larger end (again, oversimplified, but referred to colloquially as over 2.5m diameter measured at 1m above ground) is still in place, but that provision is statutory (Development Regulations) and is capable of being changed, literally (because they are Regulations, not an Act of Parliament), at the stroke of a pen.
Whatever the outcome of the State Government review and the City of Burnside Significant Tree PAR, it is clear that the push of urban consolidation and the favoured built form which presently accompanies it will see the loss of more and more trees, especially those of substantial size. Developers and builders prefer a clear block to maximise the choices of the built form to go on it and to maximise access and facilitate construction.
The 20th Century (for ease of description) life-style included a preference for housing with substantial areas for gardens and play. Most house blocks had a sand pit, some form of playground equipment, or at least a Hills Hoist rotary clothesline for children to swing on (against their parents' instructions). Up until the mid-20th Century, playing football in the street was commonplace. As traffic and danger increased, the back yard had to be sufficient even if it meant that the cricket pitch or the football field was rather scaled down. Having a good-sized back yard, safely fenced from the street, however, was a significant part of family living choice, so that the children could play and their pets could be looked after with minimal parental supervision.
Not only does urban consolidation as practised make this uncommon, the actual desires of families have changed. This is a lifestyle that is not being foisted on all of its participants. On the contrary, it is now commonplace for young adults to eschew large gardens and the work that they entail and for small, paved outdoor space to be preferred for ease of maintenance and perceived aesthetic qualities. Houses are not necessarily smaller; indeed often they are larger, with individuals seemingly finding increased value in indoor spaces and activities.
This type of built form accommodates adults satisfactorily, whatever its effects on the environment and infrastructure. Children, however, still need physical exercise for healthy physical and mental growth and this is poorly accommodated in this type of built form. Increasingly, demands are likely to be made upon local government to provide the space that formerly was found in private settings and families will look to local government to provide a substitute for the backyard that is no longer available. Our present number and layout of parks will not suffice. Local government is reaping increased rates from the rise in values and density, but ultimately will pay more than it has gained by way of the cost (using public funds) of providing and maintaining the missing private backyard space. Similarly, the provision of substantial trees is likely to fall increasingly upon the shoulders of local government because of the site limitations brought about by urban consolidation.
The City of Burnside can only work within its Development Plan. The content of its Development Plan is not within Council's control, but is constrained by many factors. Ultimately, it requires the consent of the Minister. Government (of whatever persuasion) policy is sufficiently clear and a pragmatic approach by Council is necessary if we are to live within what is required of us but still maximise what our community sees as the crucial amenity determinants of the area.
A large tree dominates the City of Burnside logo. Community feelings have run high in relation to the destruction of the amenity of their surrounds wrought by the removal of too many trees. We can try our best to negotiate for the protection of trees in our community in terms of our Development Plan, but because our power in that regard is circumscribed, it is important to think somewhat laterally for other ways to protect the amenity of our area.
One such way is to adopt a conscious and pro-active approach to tree policy. Our ability to deal with trees on the land Council owns is pretty much unlimited. Our ability to deal with trees on private land is very much circumscribed by other interests.
Our first and simplest line of approach, therefore, might be to undertake a review of all Council-owned parks and similar open spaces with a bias in favour of developing stands or plantings of large trees, always with the wider area in mind. That is, developing them to maximise the prospects of corridors and to cater for the known bird-life in the area.
There is another line of approach, however, that appears to have gone largely unrecognised. This relates to other open public spaces – footpaths, median strips, nature strips. This involves a mind-set that seeks to identify "opportunities" for trees. A cursory look around the City of Burnside will readily reveal obvious places where this could be pursued. A readily available example is the median strip in Greenhill Road and the footpath edges in Greenhill Road, especially toward Fullarton Road. Instead of observing open space and categorising it as "footpath" or "median strip" or whatever, what is required is an active enquiring approach that seeks to see opportunities for trees rather than an acceptance of the current land use as limited to that functional purpose. Some of these public spaces may not be directly under Council's control (certain major roads, for example), but with appropriate policy in place, Council will be able to negotiate with the relevant authorities (eg TransportSA) to encourage tree planting or perhaps to obtain consent to Council undertaking those plantings at its own expense.
Norwood Parade has a row of e. sideroxylon in the vicinity of the shopping centre. They are planted in a relatively narrow median strip. They appear not to have caused serious trip damage on the brick paved surfaces or the bitumen surfaces, even though they are now quite large specimens. They may have a limited life in that they may shortly reach a stage where they do cause damage, but in the time that they have been there they have made a significant contribution to the amenity of the area through not just their physical appearance but also all of the other benefits that trees bring.
The benefits of trees are many – reduction in heat (and concomitant effects upon power used for cooling etc), reduction in damage to road and footpath surfaces, contribution to quality of air and many other benefits quite apart from the sheer joy of their appearance. A walk along the footpaths in our City discloses many wasted opportunities – places where trees could be planted without interfering with power lines or traffic signals/intersections; dead or dying trees of no significance that could easily be replaced with vigorous plantings; insignificant shrubs (possibly planted by residents) where a tree could perform a better function. Equally, there are examples of unsuitable trees – wrong type, wrong place.
If Council were to develop policy that actively pursued Opportunities for Trees, it should be comprehensive. Trees that are suitable for Mt Osmond might be unsuitable for Magill. "Unsuitable" is not just a matter of aesthetics, but of height, density, canopy size, root habit, leaf and seed drop, etc. Further, arguments for confining plantings in any particular area (eg Heatherbank Tce, Stonyfell Tank Site) to local indigenous trees from seeds of local provenance should be subjected to critical re-examination in other sites. For a tree policy to be successful and to be meaningful for the community it is intended to serve (and which pays for it), it must take account of that community's needs, not merely adopt a purist stance. In Eastwood, for example, there have been plantings of Lagerstroemia indica (Crepe Myrtle) in the past couple of years. This is a deciduous small tree. Deciduous trees have a rightful place in the community. In Eastwood, where most houses are close to the street and the streets and footpaths are narrow, it is of great importance to the residents that they have access to winter light and sun, which they will be denied if evergreen trees are planted on the northern side, immediately outside the front of a small house with its front verandah at the footpath.
This, however, is not just a task for the arboriculturalists or horticulturalists in Council's employ. An informed tree policy must also consider issues such as footpath construction. Footpaths in Eastwood, for example, are generally narrow and in times past a Council might not have planted trees at all. The built form in Eastwood, however, is quite dense and there are relatively few large trees on private land and also no scope for them. It therefore becomes important that there be street trees, so that the question is not just "what is suitable?" but also "how can the footpaths be best designed to accommodate tree plantings with safety?" Block paving is inflexible. Pressure from below simply lifts the block or blocks in the area, producing sharp, raised, dangerous protuberances. Bitumen is less aesthetically pleasing to many, but it is flexible. Pressure from below will cause the bitumen to swell for some time before it cracks and produces a truly dangerous eruption. The accepted wisdom is that over time block paving is more economical than bitumen, but this may not be true other than in areas where the paving remains undisturbed. It may be that in narrow footpaths such as in Eastwood, block paving is unsuitable. Alternatively, perhaps what is required is the application of a more imaginative approach that produces block paving (with consideration given to whether small blocks or large blocks are less dangerous in their lifting tendencies and trip consequences) in some combination with bitumen to enable a blend of both methods with a better result.
In Glen Osmond or Mt Osmond, however, the issues might be different, because although there are similar narrow footpaths (often on rather dangerous winding streets) there are substantial numbers of trees on private land.
What is required, then, ideally would be:
(a) an assessment of the extent to which our parks and reserves presently provide substantial trees and tree corridors
(b) an assessment of what opportunities exist for the planting of further trees, including an assessment of all public open spaces (median strips, footpaths etc)
(c) an assessment of what trees are suitable for the various areas of our community (whether by soil type, width and type of verge/footpath/road, geographic factors relevant to evergreen vs deciduous etc), by first establishing the criteria and then determining what trees would satisfy those criteria
(d) a re-assessment of appropriate treatments for various types of footpaths in which the trees are to be planted
(e) an assessment of what trees (as types, groups and individual specimens) are unsuitable and should be removed/replaced
(f) programme possibilities for implementing the recommendations resulting from those findings, Council-wide.
Author: Leni Palk
Councillor, Eastwood-Glenunga Ward, City of Burnside
Date: 4 September 2002
