CONTINUITY AND CHANGE IN LAND USE PLANNING FOR AIRPORTS: A CHRISTCHURCH CASE STUDY Introduction Julia Forsyth (MNZPI) and Glenda Dixon (MNZPI) Christchurch City Council Tensions between residential land uses and airports are a problem worldwide, and Christchurch is no exception. When Harewood Aerodrome opened for commercial flights in 1940, it was a small facility, five to six kilometres from the edge of urban Christchurch, and entirely surrounded by rural land. In 2010 Christchurch International Airport (CIAL) operates approximately 85,000 national and international flights per year, has an annual throughput of some six million passengers, and is the base for both the NZ and American flights to the Antarctic. Future growth projections are for up to 175,000 flights per year by 2025, when the capacity of the two runway system is expected to be reached. Christchurch itself has grown west to the point that its urban edge is now generally defined by the 50 dba Ldn airport noise contour, leaving a strip of semi-rural land only 0.5-1.5 km wide as a buffer. Narrow though this buffer is, it is greatly valued by the Christchurch community as it provides a rural gateway to the City and to the South Island, and enhances the largely residential character of the main route between the airport and City centre. Planning Context While the ground operations of the airport lie within the Christchurch City Boundary, the noise effects (as represented by the modelled airport noise contours) extend north of the Waimakariri River, and south to Rolleston. This, along with the economic importance of the airport and its associated business activities, makes planning for the airport a matter of regional interest. The importance of the airport facilities to the city and region has been recognised in the regional and district planning documents for many years, under a number of different planning frameworks. A series of early Regional Planning Schemes prepared from the late 1950s onwards by the Christchurch Regional Planning Authority and the Canterbury United Council set an urban fence for Christchurch, and established a green belt between the City and the airport, both to protect the airport and to encourage urban consolidation. The change to a more market-led approach to planning which emerged under the 1989 Local Government Act and 1991 Resource Management Act saw the end of the green belt separating the City and airport. The City Plan proposed in 1995 replaced the green belt concept with new restrictions on rural subdivision and intensification in the vicinity of the airport. The economic unit criteria, which had permitted subdivision down to any size if the economic criteria were met, was replaced by a 4 hectare minimum lot size, supported by policies relating to possible reverse sensitivity effects of residential uses on the airport s operations. The minimum subdivision size, airport noise contours, and the policies supporting these, are now the main constraints on urban development between the City and the airport. Much of the land in this area, as for much of the rurally zoned land in Christchurch as a whole, is in 4 hectare blocks or smaller, which although rural in character, are not generally in economically viable rural uses. The 50 dba Contour Of particular interest in the Christchurch context are the origins of and ongoing debate about the use of a 50 dba Ldn contour as a constraint to noise-sensitive activities. The INM or
Integrated Noise Model is a widely used technique to produce contours of current and anticipated noise generated by aircraft movements around airports. The relevant NZ Standard uses INM modelling and recommends the 55 dba contour as a suitable outer control boundary or area within which there should be no incompatible land uses. 1 However it also states that Councils may determine that a higher level of protection is required in a particular locality, and that the Standard should not be used as a mechanism for downgrading existing and future noise controls designed to ensure a high standard of environmental health and amenity values. In the 1995 Plan as notified, the 55 dba Ldn airport noise contour was the line of discouragement for new urban development and the 50 dba Ldn line, the line within which noise insulation was required. This was based on the provisions of the Transitional Waimairi District Plan. By the time of the 1999 Plan decisions, these two figures had been swapped so that the 55 dba Ldn line was the line of noise insulation (there was evidence that most buildings between the 50 and 55 lines would not require additional acoustic insulation to meet the indoor design sound levels in the Plan), and the 50 dba contour the line of discouragement for urban growth. This latter was based largely on evidence from overseas studies that there was at least a 10% chance that new residents within a 50 dba contour would be highly annoyed by the noise from aircraft movements. 2 Between 2000 and 2005, the use of the 50 dba rather than 55 dba contour was subject to vigorous appeal, principally from the landowners with aspirations for the development of their rural land at the edge of the City. Three Environment Court cases between 2000 and 2005 confirmed the use of the 50 dba contour. 3 In each of these cases it was recognised that there were potentially serious reverse sensitivity issues if noise-sensitive residential development was allowed to occur on any significant basis within the 50 dba Ldn line. The Court noted that the contours do not represent the current noise environment, but rather projections of future noise, and that there are benefits of local, regional and national significance in future proofing the airport s operation. It also noted that it was not clear what alternative means (to use of the 50 dba line) would produce this outcome. The Court concluded that there is an amenity impact below the 55 dba Ldn line (in particular on outdoor amenity), reflecting a general expectation of lower Ldn levels in residential and rural areas. Overall, the Court took a precautionary approach to protecting the future operations of the airport, noting that the use of the 50 dba line did not foreclose future options but preserved the potential of the land. The adjacent territorial authorities, Selwyn and Waimakariri District, have been through similar planning processes which have confirmed the 50 dba contour as a constraint to the establishment of new noise-sensitive activities, and a 4 hectare subdivision standard for land under the contour. Contesting the Buffer Despite the series of court decisions and resulting plan provisions discussed above, the buffer between the airport and City, and in particular the noise contours, have continued to be contested. An appeal relating to the future growth of Rolleston under the 50 dba contour challenged the modelling underlying the contours, rather than the use of the 50 dba contour per se. As the contours contained in Christchurch, Selwyn and Waimakariri Plans were produced in 1994, 1 NZS 6805:1992 Airport Noise Management and Land Use Planning 2 For example World Health Organisation (1980): Environmental Health Criteria 12 Noise, which indicated that 12-13% of the population are highly annoyed at 50 dba Ldn. See also Bradley (1996 ) Determining Acceptable Limits for Aviation Noise Internoise 96, and Health Council of the Netherlands (1999) Public Health Impact of Large Airports. 3 Gargiulo v CCC C137/2000, Robinsons Bay Trust v CCC C60/2004, and National Investment Trust v CCC C41/2005
there was a clear need to redraw them, using the new version of the INM model, and to include more up-to-date assumptions about the inputs to the model, such as predicted growth in aircraft movements, changes in technology affecting aircraft noise, and air traffic systems (for example simultaneous aircraft operations or SIMOPs). As part of this Court case, two new sets of contours were proposed by experts representing CIAL and the Rolleston landowners respectively. These contours were significantly different from both the previous contours and from each other. The judge instructed the various experts to work together under the chairmanship of a neutral expert who had been engaged by Selwyn District Council, and was generally accepted as a world authority in the INM modelling process. The expert panel produced a new set of contours which were accepted as valid by all parties. Although the different planning provisions related to the protection of the airport from noisesensitive land uses have all progressed through the required statutory process, they have resulted in a public perception that the airport has acted unfairly and is seeking to shift an inappropriate share of the cost of protecting the airport activities from noise complaints onto private landowners, with no offer of compensation. Newspapers have featured headlines such as Airport Land Theft, landowners have made accusations of bullying by CIAL, and local members of parliament have become involved. A private member s Bill to ensure that aircraft noise generated by the operation of CIAL cannot be used as a reason to prohibit development around the airport outside the 55 dba Ldn contour has been proposed. One landowner who is aggrieved by both the airport and City Council s actions has erected a black shade cloth fence to block the views across his land, which is in a key location at the much valued rural entrance to the City. The situation is further complicated by the fact that Christchurch City Council has 75% ownership of the airport company, with the balance owned by the Crown. This has led to a perception amongst some members of the community that the Council is in bed with the airport company, although in reality CIAL is controlled by its own board, which is separately responsible to Christchurch City Holdings Limited, a Council controlled organisation, and all planning issues relating to the airport are dealt with by independent commissioners. Regional Developments The use of the 50 dba contour is again being tested, this time at the regional level. The existence of an agreed set of contours has headed off any further attempts to question how the contours were arrived at, but the use of the 50 dba rather than the 55 dba contour as an appropriate constraint on residential development is again the focus of debate. A strategic planning exercise, or Urban Development Strategy (UDS) has been carried out by Environment Canterbury, Christchurch City, Selwyn and Waimakariri Districts, and the New Zealand Transport Agency. This has resulted in a new chapter being written for the Regional Policy Statement (RPS Proposed Change 1) which is designed to guide the growth of the sub-region for the next 35 years. It recognises the importance of strategic infrastructure, including the airport, and incorporates the airport noise contours as modelled by the expert panel. 4 The remodelling of the contours overlapped in time with the development of RPS Proposed Change 1. As the new 50 dba contour is wider and shorter than the previous contour, some proposed residential growth has been displaced from the land between the airport and City to other parts of the City. Submissions on RPS Proposed Change 1 have been heard, and the decision, issued in December 2009, confirmed the use of the 50 dba contour as the outer urban boundary, albeit with some weakening of the language around the extent to which noise-sensitive activities should be constrained with the 50 dba contour. 4 Variation No. 4 to Proposed Change No. 1
This decision is likely to be subject to appeal from both directions Christchurch City and CIAL wishing to return to the previous, stronger policy wording, and from landowners seeking that the 55 dba contour be used rather than the 50 dba contour, thereby potentially freeing their land for future urban development. This will result in 50 dba versus 55 dba debate being considered by the Court again, although in this case it will be in a more explicitly regional context. Other Complexities While the airport noise contours have been (and will probably continue to be) a significant constraint to the westward expansion of the City, they are not the only constraint. Much of the land to the west of the City lies over an unconfined aquifer, from which the City and many individual landowners draw their drinking water. Environment Canterbury has introduced significant constraints to urbanisation over this aquifer through the water quality chapter of the Natural Resources Regional Plan. 5 The provisions as notified introduce a strong policy framework and associated rules which in effect seek to freeze the existing land uses over the unconfined aquifer. Should these provisions be confirmed by decisions and any subsequent court hearings, a non-complying land use consent would be required from the Regional Council for anything other than minor land use changes. In addition, State Highway 1, currently being widened to four lanes, runs along the Eastern boundary of the airport, and is providing both incentives and constraints to the development of the adjoining land. Options for a grade separated interchange at the Memorial Avenue gateway to the City have recently been out for consultation. Land Uses within the Airport Another key factor affecting the viability of the rural buffer between the airport and City is the extent to which the airport itself becomes an urban environment. The more urban the land on the airport side of State Highway 1 becomes, the more difficult it is to argue that urban uses on the other side of the State Highway are inappropriate. CIAL s desire for non-airport related business development at the airport has been signalled since its 1985 Master Plan. The 2006 revision of the Master Plan shows a significant area (58ha) for Commercial Support Activities, extending along the edge of the airport land adjoining State Highway 1. A larger area is shown in CIAL s 2007 Strategic Vision as a Commercial /Service Precinct called Airport City and would include a business park south of Memorial Avenue and commercial zone north of Memorial Avenue for activities such as office complexes, a conference and exhibition centre, restaurants, cafes and other food outlets, gym, and a service station. A separate Freight Precinct located to the south is intended to attract not only logistics and distribution businesses but also light industrial support uses. Particularly as a result of the recent recession, CIAL has crystallised its aim to de-risk its airport business with alternative income streams. It has explicitly stated that it desires to obtain 60% income from non-airline sources, whereas the current figure is only 40%. This is in line with development of airport cities internationally. CIAL made submissions to RPS Proposed Change 1 for inclusion of the airport as a Key Activity Centre, the terminology used in that document to describe the City Centre and other key retail hubs in the City. They were, however, unsuccessful in this regard in the Commissioner s decision. CIAL has been active in pursuing resource consents for businesses unrelated to the airport activities. A recent application for a lessee business for document storage and retrieval was 5 Variation 6 to Chapter 4 of the Natural Resources Regional Plan.
approved, with the airport arguing that the reason for the rule limiting activities was for the purposes of the airport running out of land to its own detriment or to the detriment of the rural area s land and soil resources, rather than to any wider issues of business distribution in the City generally. The airport has lodged a resource consent application for a retail complex on the corner of Memorial and Russley Roads, which has raised concerns it will attract custom from beyond the airport and challenge the City s retail distribution strategy, which focuses on maintaining and enhancing the existing commercial centres, rather than developing new ones. CIAL representatives have noted a developing tension between their interpretation of the airport purposes designation and the City s interpretation. CIAL has a legal opinion which argues that a wide range of commercial activities and facilities could comprise a modern airport, and that the actual use of airport land can vary at different times. This opinion argues that the designation for airport purposes can cover any purpose which is associated with and consistent with an airport, without being directly connected to aviation activities per se. Christchurch City s contrary legal opinion is that the scope of activities covered by the designation should be determined on the plain ordinary meaning of the term airport purposes and that would not, in most cases, extend to commercial activities. To date neither party has sought a declaration from the Court, as there are attempts to set up a process by which the City and the Airport Company would work jointly to review the future of the designation and the Plan provisions. Similar tensions exist with the Special Purpose Airport Zone in the City Plan, which CIAL would like to see widened. It is intended that development within the airport zone be clearly associated with the operations and associated functions of the airport and aviation. Business development which has little or no relationship with the airport is provided for elsewhere in the City, to ensure that the availability of land within the airport zone is not unduly restricted for airport uses. Policies in the City Plan are supportive of the airport s operation and its need to grow and develop over time, subject to protecting surrounding land uses from adverse effects. However there are no objectives and polices which directly address the type of land use which could be acceptable within the airport zone, or which set out how the airport fits within the City s strategic directions for business, including retail or office distribution or industrial land use generally. This means it is difficult to refuse non-complying activity applications, and the Plan provides little guidance on the point at which further non-airport related activities will become unacceptable. The Future of the Buffer Given the range of pressures on the semi-rural buffer between the airport and City discussed above, planning for the future of this buffer (some 850 ha), plus the 720 ha of Special Purpose Airport zone, presents a considerable challenge. It is difficult to envisage that the outcome of the 50 dba versus 55 dba appeals will be an overturning of the long-established use of the 50 dba contour as a constraint to urban development, although this is still a possible outcome. The commissioners who considered the future of the land between the airport and the urban area for RPS Proposed Change 1 proposed a special treatment area, with planning for its future development to be completed by 2012. The discussion in the decision points to nonnoise sensitive urban land uses (essentially business uses) and / or some lower density residential or rural-residential use (the latter was, incidentally, dismissed as an outcome in NIT v CCC (op cit)). Their view that the future of the buffer is largely urban may have been driven, at least in part, by their decision to include all of the Special Purpose Airport zone within the urban limit. They were also of the view that once land is no longer able to be used for economically viable rural production, it should necessarily become available for urban development. This latter point seems to take no account of the undoubted popularity of the 4
hectare pony farm. Inefficient though these may be in residential density terms, they do successfully maintain a largely rural amenity, and retain the future possibility of productive rural uses. Christchurch City has appealed this decision on a number of grounds, but recognises that a new planning exercise for the entire area needs to be undertaken. The existing Rural zone may no longer be the most appropriate. However any new planning provisions must successfully balance the need to protect the airport from noise-sensitive uses; landowner aspirations for development; community expectations about maintaining a rural entrance to the City; increasing urbanisation of airport land, protection of the unconfined aquifer; and the efficiency of the current and future State Highway operation. Christchurch is fortunate in that it is not unduly constrained by its geography and has therefore a number of other locations for future urban development over the next 35 years, as well as a strategic intention to accommodate an increasing proportion of growth within existing urban areas. This flexibility, coupled with the precautionary approach to protecting the airport operation confirmed by the Environment Court, may mean that at least some limitations to urban development between the airport and the City are maintained. The views expressed in this paper are those of the writers and do not necessarily represent those of the Christchurch City Council