Forest Remnants and Urban Consolidation

Forest and Bird, Issue 282, 1 November 1996, Page 42

Forest Remnants

and Urban Consolidation

is intill housing the answer to urban sprawl? A patch of bush is cleared in the bottom of a secluded gully; 13 town houses are crammed into a long narrow section that was previously occupied by one house and a large bush garden; Forest and Bird is rung by an concerned resident saying that a neighbour is clearing the forest at the back of his section. DAVID RELPH looks at some of the effects of the new phenomenon of infill housing which is causing drastic changes to parts of Auckland City and to a lesser extent in other cities such as Christchurch.

ONSERVATIONISTS tend to be largely occupied with issues which affect areas outside the city. Yet most of us live in urban areas, and it is the growth of cities that increasingly generate some of the most significant environmental issues. For most of the past 150 years, New Zealand’s cities have devoured the surrounding countryside as they expanded in an unplanned way. In the past five years our population has increased by 225,414 or 6.6 percent and that growth has been increasingly intensive and rapid round Auckland. Absorbing over half the national increase — 119,240 residents — Auckland has grown by almost twice the national average. In a country that we have fondly imagined to be uncrowded and relatively lightly populated, New Zealanders have belatedly begun to realise that urban sprawl brings with it many problems. The provision of transport and services such as stormwater and sewage _ disposal becomes increasingly difficult and expensive, and low-density housing patterns encourage high levels of private car use with all their accompanying environmental costs.

Few conservationists would be happy to see a continuation of the inexorable spread of new subdivisions that have been such a feature of New Zealand’s cities in the past. But what are the alternatives? Winding back population growth is an obvious longer-term option, but while this growth continues, the only real way to avoid the physical expansion of a city is to intensify the density of dwellings within built-up areas. This is infill housing. In itself it poses the dilemma of how to increase housing density without significantly reducing the quality of the environment in the affected suburb. CLOSER LOOK at what is hapy a in Auckland City reveals that the issue is not a simple one. Auckland Regional Council has attempted to halt suburban spread by zoning certain boundaries as green belts. This has led to bitter legal challenges from North Shore City, Rodney District and from developers who had bought the attractive rolling farmland on the northern boundary. The courts have upheld the ARC’s urban limit and have declared that local councils can incorporate limits to urban development in their district plans. It is within the confines of Auckland

City , (an A4 area covering the Auckland isthmus), that the most marked development of infill housing in New Zealand is taking place. While the outer cities of the Auckland urban area are partly developing through new fringe housing developments, Auckland City’s new growth is nearly all infill. The city council has a stated goal of 100,000 more residents on the isthmus (an increase of around 25 percent). The location of this increase has recently been refined through zoning, and it is planned that large proportions of it be absorbed in certain defined areas — particularly around the inner city and business centres. LTHOUGH INFILL housing is a solution to one environmental and social problem, it frequently provokes strong local protests over the marked effects on the urban natural environment. At its most intensive, larger trees disappear from the skyline and the

vista becomes one of closely spaced twostoreyed houses, high walls of painted plaster and paving and the little space available for greenery tends to be mown grass or neat landscaped areas. In areas where the zoning permits, large blocks containing multiple dwelling units have become the norm. In some suburbs the intensity of new housing is extremely high. In St Heliers, for example, 14 percent — or roughly one house in eight — has been built in the past five years. In the Eastern Suburbs of Auckland, concern centres particularly on a dozen small gullies that still retain strips of indigenous bush, which in most cases are on parts of rear sections in private ownership. Generally the bush is largely mature kanuka, often in good condition, though several sites are heavily infested with invasive weeds and rubbish. The remnants represent the last vestiges of the original forest which covered most of the Auckland isthmus. This is borne out by analyses of pollen from swamp soils from sites such as the present Queen Street. Kanuka most often is the dominant tree, with other significant species including a variety of

broadleafs; in some gullies there are fine groves of nikau or cabbage trees, and a few large totara and other podocarps. In each valley the bush remnants are not only a notable landscape feature but, combined with adjoining gardens, they still provide diverse habitats that can supply the year-round food needed by nectar-sipping and fruit-eating native birds. These areas are the only parts of the city still able to support significant numbers of fantails, silvereyes, grey warblers, and the occasional tuis and moreporks. One study of a small bush patch in Remuera identified nine species of native birds. Kereru still regularly visit bush sites in Parnell and on the slopes of Mt Eden. As the number of sections available for development decreases, pressure is increasing to subdivide those sections with bush on them. Apart from the direct loss of these natural remnants, intensive infill housing puts stress on other services. Existing stormwater drains are under increasing pressure and at times of peak flow the sewerage system frequently overflows into the stormwater system. While increased population densities should supposedly lead to more viable public transport and less reliance on cars, it doesn’t always work that way. Increased traffic congestion created by infill developments is partly responsible for the revival of a controversial project to build a motorway through the Eastern Suburbs and across the wetlands of Hobson Bay. The city council has also noticed increased pressure on public spaces for recreation. This is a direct result of increased living densities and reduced private space. F WE ARE TO LIMIT urban sprawl, is the loss of remaining natural remnants inevitable? Not necessarily. There are ways of allowing considerable

Two approaches to infill developments

HE PROBLEM OF saving urban forest and the contrasting extremes in development applications are no better illustrated than in a patch of bush on the border of Kohimarama and St. Heliers in Auckland’s Eastern Suburbs. This piece of remnant forest extends for about 400 metres up a steep gully between two fully built-up streets. Mature kanuka with a 10-metre canopy, the area is nowhere more than about 40 metres across. Apart from one section owned by the city council, the whole bush gully is on the rear sections of about ten privately owned properties and forms part of the view of at least 100 others. Most of the ten sections that abut the bush are quite large and under current zoning can be subdivided — in some cases for several new dwellings. 3 In 1993 a developer obtained one of

the properties and applied to build five houses largely on the steep forested slope behind the existing house. This involved the removal of most of the bush including 14 protected trees. The council decided the application was nonnotifiable and gave the developer approval to remove the trees and set up a building platform. The first notice the surrounding residents had was when they heard the chainsaws in action. After months of angry communications with the council, the 30 surrounding residents obtained an interim injunction halting the developer from further clearance pending a High Court hearing in early 1995. At this hearing, the developer was refused consent to build more than one house or to remove any more trees although by this stage the slope had been denuded of most of its

larger trees. He has appealed the decision to the Planning Tribunal and the residents now have to decide if they can afford to go through the court process a second time. A year later the bush was under siege again but this time the result was different. Two owners at the eastern end of the gully combined their sections and applied to develop the upper end of the bush. This time the applicants spent a great deal of time and money developing a plan that will disturb the bush as little as possible, consulting council officers and all adjoining residents at some length, taking interested groups on lengthy visits to the site, and modifying the plans to take into account any objections. The plan, however environmentally sensitive, still involves a compromise and the loss of about a quarter of the bush. What is left will be enhanced by the

removal of invasive exotic scrub and an extensive replanting programme. The developers were also happy to agree to Forest and Bird’s condition that a covenant be put on the title preventing new owners removing further bush.

While ideally Forest and Bird would have liked the council to buy all the bush and manage it as a reserve, realistically it was felt that the application, in a privately owned site inaccessible to the public, was an acceptable compromise.

infill housing without severely reducing the quality of the urban environment. This will only happen when local councils ensure that developers retain natural vegetation and open spaces. Such council policies in turn will depend on the attitudes of residents how much we value a pleasant urban environment, and how much we are prepared to pay for it. Auckland City Council has gone some way towards protecting its forest remnants. The council’s current tree protection ordinances require that in most areas resource consent is required to fell or prune indigenous trees of more than 600 mm diameter and six metres high, or most exotic trees of 800 mm diameter and eight metres high. This involves consultation with interested parties (neighbours

etc), arborist reports and a hearing before a council committee. Hearings result in quite rigorous assessment of applications, and have seen a number of subdivision applications involving the removal of groupings of trees being turned down. Forest and Bird’s Central Auckland branch has been involved in a number of these hearings and its impression is that more recent development applications have tended to be more carefully planned, with existing vegetation considered, and plans for replanting included. But there is now a backlash to what are perceived by many developers as costly, time-consuming and rigid processes. In June this year a group of Auckland City councillors moved to alter the tree protec-

tion regulations — to increase the protected tree diameter to 800 mm and the height to eight metres for indigenous trees, with a similar increase for exotics. Estimates suggest that this would make perhaps 40 percent of currently protected trees vulnerable to development. While some rationalisation may be needed, this solution would be a disaster. Apart from such tree protection regulations, it is important also that local citizens and interested pressure groups such as Forest and Bird keep pressure on local councils to continue to work on finding other ways of preserving significant vegetation and developing more open natural areas. It is important that most applications to remove areas of natural vegetation are publicly notified by the council. The buying of back sections by council to aggregate bush patches and convert them to reserves should be considered in some instances despite the cost. Changes in zoning, and rate relief for bush owners as compensation for not developing a site, are other options. In the end it all comes down to how much we value remnant vegetation in the urban environment. Councils will only act if

sufficient pressure is imposed on them. Urban trees and bush have enormous values — in their appearance, in softening and framing more distant views, as wildlife habitats, and for their heritage values. In addition of course, they have functional values in providing shade, shelter, privacy, noise screening and air purification. It is worth noting that in many overseas cities suburban trees are regarded as great community assets. The enormous value of diverse urban ecosystems of forest and gardens is emphasised by the comment of an ornithologist at a recent infill housing application hearing that if the current hunting of kereru in rural areas continues, urban habitats may be the

only hope for the survival of this species in the future. The real significance of these forest patches comes from their survival in the midst of a city, surrounded by development. This gives them great social, aesthetic and recreational importance. ®

Davip RELPH writes science text books for secondary schools. He is also a freelance natural history, conservation and travel writer.