Drainage
39 The drainage issue concerns the likely impacts arising from the applicant's interim proposal to alter of the existing flow regime in the non-urban context, in order for the development to proceed in advance of the ultimate drainage system. This interim solution comprises:
- earthworks involving benching of the site to provide building platforms,
- filling of the existing watercourse/dam and its re-alignment to the north, adjacent to the FLS,
- the construction of gabion-type weir to intercept and mitigate the discharge rate into the existing downstream watercourse.
- the construction of a perimeter road adjacent to the eastern boundary under which an OSD system is to be partially constructed that also discharges into the proposed weir.
40 Accordingly, Mr Lysenko has undertaken a preliminary assessment of the runoff from this catchment area and says that it is relatively small and that the OSD system can be readily designed to ensure that in the interim period, the post development discharge will not exceed the pre - development discharge. Subsequently, when it is practical to construct the new FLS in conjunction with the adjoining downstream property, the aforementioned discharges can be diverted into the road reticulation, thereby eliminating overland via the watercourse.
41 Ms Sivakumar addressed the current engineering controls including the following provisions of the Indicative Layout Plan (ILP):
- street network to be based on road hierarchy and to provide interconnected streets that give safe, convenient and clear access within and beyond the Precinct.
- selected roads to incorporate swales, WSUD infrastructure as part of Integrated Stormwater Management
- riparian corridors, which are to protect, restore and enhance the environmental values and functions of watercourses and riparian corridors.
42 Consequently, she says that the installation of OSD systems are now redundant within the current Water Sensitive Urban Design (WSUD) catchment management strategy, which incorporate conventional drainage systems to convey the stormwater runoff from developments to designated regional basins, which are part of the trunk drainage system that mitigates any flooding.
43 Ms Sivakumar does not consider the proposal complies with the WSUD or other DCP provisions and identifies the following 3 options:
- Option 1 (Do nothing); No development to be without public road access, whereby the existing condition of the locality is maintained so as not to heighten the social and financial liability of council. As the proposal does not satisfy this, she consider it should be refused.
- Option 2; (No change) This is to allow the proposal, which she considers unreasonable because it does not initially comply with the ultimate drainage strategy.
- Option 3 (Compliance with NKP outcomes); This would require the regrading of the land so as the enable construction of temporary drainage structures along the FLS. Where extended earthworks are involved along the downstream common boundary, then agreement for filling and easements should be required.
44 From her assessment of the compliance requirements in the NKPDCP, she does not consider the proposal incorporating the OSD is satisfactory.
45 Insofar as there is a comprehensive set of controls in the NKPDCP to achieve the desired environmental outcome, it is apparent to me from the evidence that there is no coordinated infrastructure-staging plan for the construction of the new internal local roads and drainage systems. This causes considerable inconvenience when neighbouring property owners do not wish to develop concurrently.
46 This is the situation in the current matter where the Moran development wishes to proceed with its '150 bed total-care' development but the adjoining and lower level lot (No 57-69 SR Drive) has no current approval. Therefore no final neighbourhood arrangements have been possible to achieve the construction of the new internal FSL, which will incorporate the ultimate drainage system.
47 In these circumstances, I think it is reasonable to consider the individual site location and associated constraints, to determine whether developments can proceed on an interim 'piece-meal' basis. Otherwise the owners of strategically located land designated for access and drainage disposal could thwart orderly development if they are not prepared to negotiate reasonable access and servicing arrangements.
48 In an overall consideration, it appears to me that there are community benefits by allowing this development to proceed providing the environmental impacts can be adequately addressed. In considering the interim drainage solution, I note the provisions of Section 6 - Managing the Environment of the NKPDCP, wherein section 6.1 includes the following objectives for integrated stormwater management:
1 To ensure that appropriate stormwater management measures are implemented to maximise opportunities maintain and enhance the quality and integrity of urban waterways through both the construction and occupation phases of development, while encouraging and creating an urban form where risks to life and property, as a result of either minor or major flooding are minimised,
2 To maximise opportunities for a best practice Water Sensitive Urban Design Approach at the individual lot, overall development and regional scales,..
6 To minimise the impact of nuisance flooding to a level to the community; and…
49 Accordingly, I am satisfied that the interim drainage solution by the applicant reasonably satisfies these objectives. The watercourse diversion to the gabion-type weir and OSD system should effectively control any water quality and increased rate of runoff concerns from the new development, so that the post-development discharges do not exceed the pre-development discharges.
50 Taking into account the nature of the downstream discharge via the OSD and gabion weir structure, it will be mostly in line with the existing discharge point, which is along an apparent natural watercourse through an undeveloped rural property. It seems to me that this individual lot, "interim drainage" proposal will minimise the impact of nuisance flooding and any flooding risk to persons or property.
51 In this regard, I have also given consideration to the applicant's agreement to conditions, which trigger the construction of the FLS, so that the interim drainage system can then be connected into the ultimate road drainage system. I rely on the levels Mr Lysenko submitted that this can be achieved.
Conclusions
52 Having considered the evidence, the submissions and undertaken a view, I consider this application merits conditional consent. The development is located within the North Kellyville release area, which has been subject to extensive environmental investigation resulting in comprehensive planning controls to allow large-scale residential and associated development.
53 The subject development is permissible within the R2 Low Density Residential and SP2 Infrastructure zone. In support of the application the applicant has submitted various government papers supporting the short - term need for aged-care facilities in this area. Accordingly, I accept the applicant's submissions that there are community benefits in achieving the development of this type of facility.
54 However implementation of this allowable development is compromised because it is the 1st development in this sub-catchment area where the ultimate road and drainage infrastructure is not available. But this depends on some development actually commencing so that s94 funds can be progressively obtained. This might mean that some compromised amenity is necessary in the short term.
55 Unfortunately the controls do not provide any guidelines for the 'piece-meal' implementation of development. Therefore considering the public interest benefits of progressing the development, it seems reasonable to consider whether appropriate interim servicing measures can be undertaken, which facilitate the development without adverse environmental outcomes and which enable the development to ultimately comply with servicing controls.
56 With respect to the temporary road access, I accept the expert's opinion that temporary access onto Samantha Riley Drive can be maintained providing additional safety works are undertaken at the driveway/road connection. Also, that conditions can be imposed that effectively trigger the new rear road access (FLS) in conjunction with the adjoining development.
57 The associated servicing issue concerns the drainage issue. In this case the upstream non-urban catchment is relatively small. Therefore I am satisfied to rely on Mr Lysenko's evidence that the OSD and watercourse works can effectively restrict post-discharges from the site to not exceed pre-development conditions. Whilst it then discharges into the existing watercourse, there was no evidence to indicate that there would any significant risk to person or property. Importantly, I understand that the proposed drainage system can be connected to the ultimate drainage scheme within the FLS, when it is constructed in conjunction with neighbouring developments.
58 The remaining issue concerns payment of reasonable s94 contributions towards transport infrastructure. For the aforementioned reasons, I consider it reasonable to maintain the s94CP methodology but reduce the occupancy factor, as agreed by Mr Kendal, to ascertain the appropriate contributions.
59 Consequently the issues before the Court have been addressed to enable the conditional consent to be granted. However the draft conditions include a deferred commencement condition requiring a drainage easement to be obtained from the downstream property owner. In the circumstances of the temporary drainage works, which maintain very similar discharge characteristics to the existing and noting that the adjoining rural property is subject to development, I do not consider the condition reasonable. Likewise, I do not consider conditions to construct part of Samantha Riley Drive reasonable when the s94 contributions apply.
Court orders
60 The Court orders that:
1 The appeal is upheld.
2 Development consent is granted to DA 1902/2008/HB for the construction and operation of a 150 bed residential care facility at 57 Samantha Riley Drive Kellyville subject to the conditions in Annexure A.
3 The exhibits may be returned except for 1, 2, A, C, K and L.
R Hussey
Commissioner of the Court