The final deadline was set at 31 May for submissions on the Hills Council’s applications to the NSW government to change the zonings in their local environment plan and insert some special provisions in the development control plan. These changes will facilitate development on the land owned by Mirvac that currently contains the old IBM corporate headquarters on the corner of Coonara Road and Castle Hill Road in West Pennant Hills next to the Cumberland State Forest.

The basic framework of the proposals is unchanged from earlier plans described in STEP Matters (Issue 198). The main purpose of the council application at this stage is to facilitate the development of 600 dwellings. Ancillary aspects are that, if the housing development proceeds, Mirvac will sign a voluntary agreement to allow the existing playing field on the land to become public open space and pay for the development of a soccer field with synthetic turf and the necessary public access road.

The design of the housing development will be subject to further scrutiny at the development application stage but if these current plans are approved, the basic framework will be set in concrete (lots of it!).

Even though part of the site is currently developed as a corporate park, these buildings are surrounded by mature tree plantings. The majority of the site is classified as Blue Gum High Forest or Sydney Turpentine-Ironbark Forest, both critically endangered. This is a unique opportunity to preserve one of the few remaining areas of high quality vegetation and its associated fauna habitat in north-western Sydney. Its proximity to Cumberland State Forest adds to the value of this preservation through its connectivity and boosting of resilience of the vegetation.

Hence STEP is opposed to the whole development proposal.

Future of the forested area

The future management of the large forested area that is to be zoned E2 (environmental conservation) which contains critically endangered ecological communities and fauna, is completely unknown. The development control plan amendment relating to the site refers to the residents as being responsible for the cost of maintenance of the 'significant vegetation'. This is totally unrealistic.

It is essential that a stewardship or conservation agreement be established defining responsibilities and funding of management together with a vegetation management plan. This should be in place before any dwellings are occupied.

As the E2 land will be for the benefit of the whole local community, not just the residents of the Mirvac developments, it is appropriate that the Hills Council be responsible for its management.

Synthetic playing field

The proposal for the synthetic playing field should not go ahead until the environmental impact of the use of this surface is thoroughly assessed. A detailed analysis is required of the impact on the bushland below the field of:

• stormwater runoff from the hard surface
• runoff of degraded synthetic grass and substrate pieces
• the loss of soil biota under the artificial surface
• the risk from a fire in the surrounding bushland spreading to the field
• conversely, the surface itself is mostly made of rubber and will be much hotter than in the surrounding vegetated areas, so what impact will this have on the bushland and wildlife?

Of course no floodlighting should be allowed so close to bushland that is home to several nocturnal species such as the Powerful Owl and several species of bats.

Development plans

The image at the top of the page shows the proposed layout of the development. The medium density housing area (200 dwellings) is along the edges of the site while the high density zone (flats up to six stories) is lower down next to the forested areas.

The main argument from Mirvac in favour of the development is its proximity to the new Cherrybrook Metro Station. Residents will however have to walk up a steep hill and cross Castle Hill Road to get to the station. The shortest possible walk is 800 m. The other side of Castle Hill Road which is in the Hornsby Council area is currently zoned low-density residential that will no doubt be planned for higher density development in the future as the station is now operating.

Overdevelopment

The major reason for objections to the proposals is the level of development. The residents of West Pennant Hills have rallied strongly against the proposals. Over 4,000 objections have been received by the Hills Council. They are concerned about the increase in traffic on already congested roads as well as the environmental impact of the development.

The main point is that the existing IBM corporate park is a valuable asset. The buildings should not be knocked down. With a bit of imagination alternative uses could be found that will not lead to destruction of the mature native vegetation that surrounds the buildings and the car park.

In any case the council and Mirvac have not demonstrated that there is a need for this huge housing area. We note that the Department of Planning document Cherrybrook Structure Plan: Vision for Cherrybrook Station Surrounds (September 2013) does not envisage any residential development on the site. Increases in housing are planned for neighbouring areas north and further west of Castle Hill Road with a total number of new dwellings planned of 3,200 by 2036.

The plan is an example of the notorious spot re-zonings that have plagued development in Sydney. A developer comes up with a plan that is outside the planning guidelines. The local council knocks it back so the developer is able to go directly to the Department of Planning to gain approval via the Gateway Process. The new planning minister, Rob Stokes, has stated that this system will not continue but we will have to see how that can come about.

As Hornsby Council says in their submission:

Any decision for this site should be deferred until a precinct-wide structure plan or strategy is adopted for all the land parcels surrounding the Cherrybrook Metro Station.

...

The proposal by Mirvac to redevelop the subject property for residential purposes is likely to trigger further owner/developer-led spot rezoning applications in the area. This would lead to an ad hoc approach to land use planning for the Metro Station precinct. The process would undermine the planning framework for both councils and lead to poor outcomes for the Cherrybrook community.

Housing plan is overdeveloped

The documents indicating the layout of the medium-density housing precinct show houses that are crammed together, some on blocks as small as 86 m2 that are only 4 m wide. Even with some of the wider lots most of the street will be taken up by driveway access.

There will be little space for street trees. The front and back yards will also be too small for trees to grow with a beneficial canopy.

The design of the subdivision needs to take account of the need for liveability of streets in the face of current heat in summer and expected increases with climate change.

There are also several other concerns about the details of the development and how it will impact on the surrounding forest. These relate to clearing of riparian zones and impingement of asset protection zones into the E2 area and Cumberland State Forest.

We have covered several of these concerns in previous comments on this proposal. They are very concerning but basically STEP is opposed to the development in its entirety.

Conclusion

Mirvac’s website reveals the company’s Biodiversity Policy. The policy states:

At Mirvac, we aim to be an overall positive contributor to environmental sustainability. We firmly believe that responsibly managing our biodiversity impacts will enable us to strategically assess biodiversity-related risks and opportunities and anticipate and respond proactively to emerging regulations and societal expectations.

Mirvac’s plans for the IBM site are clearly not compatible with their Biodiversity Policy.