Cavill Properties Pty Limited v Warringah Council

[2011] NSWLEC 1372

Land and Environment Court

New South Wales

Medium Neutral Citation:

Cavill Properties Pty Limited v Warringah Council [2011] NSWLEC 1372

Hearing dates:

14, 15 December 2011

Decision date:

15 December 2011

Jurisdiction:

Class 1

Before:

Hussey C

Decision:

Appeal upheld, modifications allowed

Catchwords:

Development modification: modifications to 'as-constructed' on-site drainage retention system to achieve adequate retention volume, water filtration and inlet capacity

Legislation Cited:

Environmental Planning and Assessment Act 1979
Warringah Local Environmental Plan 2000
Warringah Development Control Plan

Category:

Principal judgment

Parties:

Cavill Properties Pty Limited (Applicant)

Warringah Council (Respondent)

Representation:

Counsel
Mr I Hemmings (Applicant)

Mr N Howie (Respondent)
Solicitors
Minter Ellison (Applicant)

Wilshire Webb Staunton Beattie (Respondent)

File Number(s):

10940 of 2011

Judgment

1. This appeal was lodged against council's refusal of a s96 application to modify the requirements of a development consent relating to the on-site drainage for a 48 unit residential flat building located at 1262 Pittwater Road Narrabeen.

1. The residential flat building (RFB) has been substantially constructed and an alternative drainage system constructed to that approved. Whilst it includes the 3 absorption/retention tanks, the as-constructed works now include Atlantis Modules with a reduced retention area and reduced water filtration and entry structures.

1. The council is dissatisfied with the performance of this alternative system because it has smaller retention capacity, the council's expert raised some concerns about the Atlantis modules suitability and it does not incorporate effective water quality filtering.

1. Consequently the council has refused to endorse a positive covenant, which was one of the original conditions of the consent, to the effect that the covenant prescribed a maintenance regime for the on-site drainage system and which council did not consider satisfactory to apply to the as constructed system.

The evidence

1. The drainage details were assessed in a joint report by

• Mr M Shaw consulting engineer for the respondent, and
• Mr G Ryan consulting engineer for the applicant.

1. From his site inspection, Mr Shaw found that:

• Silt and debris was observed at the base of both inlet pits to Tank No 3. This silt was restricting flows through the geotextile to the tanks below and approximately 50-100 mm of ponded water was observed at the base of both pits;
• A clear debris/water mark at the level of the overflow pipes from the inlet pits to Tank No 3 was present in both pits. This water mark indicates that the overflow activation level is commonly experienced in both pits;
• Significant ponded water was observed in the inlet pits to Tank No 2. Approximately 600 mm depth of ponded water was observed in the southern inlet pit and overflow to the street was active. The ponded water in the northern inlet pit was measured at approximately 300 mm depth;
• A clear debris/water mark at the level of the overflow pipes from the inlet pit to Tank No 2 was present in both pits. This water mark indicates that the overflow activation level is commonly experienced in both pits;
• Nuisance ponding and surcharging from the surface inlet pits was observed in the part of the drainage system in the north-east of the site and
• No incoming/outgoing pipes were observed for the northern inlet pit of Tank No 1. Sediment and grass clippings were observed to be accumulating above the geotextile for the northern inlet pit of Tank No 1. Approximately 550 mm depth of ponded water was observed in the southern inlet pit of Tank No 1 and the overflow to Tank No 3 was active.

1. After the initial assessment, the engineers agreed that there were a number of deficiencies with the as constructed drainage system and Mr Shaw confirmed his particular concerns about the size of the retention tanks, the inadequacy of the water quality filtering systems and the ultimate discharge into the public domain.

1. Consequently, during the appeal the engineers undertook further conferencing and agreed on a number of modifications as shown in the plans in exhibit A.

1. These modifications involve the expansion of the individual retention tank volumes in line with the original volumes approved and make provision for Tank 1 with the existing tank volume to be expanded by 6.4 cubic metres utilising the Atlantis or equivalent modules and inclusion of Atlantis filtration control unit and inlet pits of 900 mm x 900 mm. Similar expansions and modification are to take place with Tank 2 and Tank 3.

1. In addition to this, the engineers have agreed on a maintenance programme to ensure the operational efficiency of this modified on-site drainage system.

1. The maintenance system is covered within the agreed conditions whereby there is to be a positive covenant for on-site stormwater drainage and the maintenance programme involves an inspection of the filtration units adjacent to each tank every three months and cleaning out of these structures. Furthermore, there is to be an annual inspection basis over the first 3 years and then a periodical inspection of the operation efficiency on a 3 year cycle, I understand.

1. There is also to be a condition, which is designated condition 45A that requires the Owners Corporation to amend the existing by-law which grants exclusive use to the ground level communal land where the retention tanks are located. The parties have agreed to these conditions.

Conclusion

1. My conclusion is that having considered the evidence and undertaken a view I am satisfied that appropriate orders should now be made, based on the agreed conditions.

1. The s 96 application relates to the same development. The Court was not informed of any objections and on merit I consider the application satisfactory.

1. Importantly the retention volumes of all the tanks have now been expanded to the order originally approved and the reservations about using the Atlantis modules in the subject context overcome.

1. I accept that the as constructed inlet structures to the tanks are unsatisfactory in terms of water filtration and entry and maintenance requirements.

1. However it now seems that the agreed modifications should achieve a satisfactory stormwater management outcome and in this regard I rely on the agreements of the engineers and I will make the orders.

Court orders

1. The Court orders that:

(1)   The appeal is upheld.

(2)   The section 96 application in respect of the approved stormwater absorption tanks in relation to the residential flat building erected at 1262 Pittwater Road, Narrabeen to modify development consent no. 2009/1446 granted by the Respondent on 10 March 2010 is approved subject to the modified conditions in Annexure A (such modified conditions being marked with an asterisk followed by the words "LEC MODIFICATION DECEMBER 2011").

(3)   The exhibits, except exhibits 1, 3 and A may be returned.

R Hussey

Commissioner of the Court

Decision last updated: 10 January 2012