26 The experts disagreed as to the reliance that should be placed on the Flood Management Plan. Mr Marshall was of the opinion that since the shed is located above 1.5m AHD there is adequate flood warning of 18 hours for people to clear the shed of its contents, fix open the doors and evacuate the area; and that a permanent caretaker will be on site to implement the plan of management. Mr Marshall agreed that the value of the Flood Management Plan depends on the owner following it, but was of the opinion that it reflects commonsense, and is an attempt to minimise risk. In his opinion there is a difference between a habitable building and an agricultural shed; while the shed is in a high hazard area, with adequate flood warnings the risk is very low. Mr David was of the opinion that there is no guarantee that present or future owners would have a caretaker permanently on site to implement the plan of management, and that in the event of a flood the shed could uplift and pose a threat to public safety and property. Mr David was of the opinion that in a 20 year flood the shed would be in a high hazard area.
27 On the issue of precedent, Mr David was of the opinion that approving a shed in a flood affected area would set a precedent for other structures to be built within the flood plain, and that the addition of more structures could ultimately cause flood levels to rise and inundate structures currently unaffected by flooding. There was a risk as it is not possible to stop people walking around in floodwaters for example to salvage things. Mr Marshall agreed that no cumulative impact studies had been completed, however was of the opinion that it is unlikely that permitting similar structures in the high hazard area would have any significant cumulative impact due to the large holdings and limited potential to build on properties. On the issue of whether there was a significant risk to human life or injury, Mr Marshall stated that based on the Lower Hawkesbury Flood Study, there would be 18 hours before a flood reached a level of 1.5m; the river banks at the site are 1.8-1.9m; and it would take 48 hours or so to reach the height of a 100 year flood, which is a long time to evacuate people, and would provide an adequate safeguard.
Conditions
28 There are two proposed conditions that are in dispute. The Council's draft Conditions of Consent include a deferred commencement condition in the following terms:
1. Deferred Commencement
Pursuant to section 80(3) of the Environmental Planning and Assessment Act 1979, this consent does not operate until:
(a) A Building Certificate for the existing shed has been issued by Council, or Council has advised under section 149D(3) of the Environmental Planning and Assessment Act that completion of the further work to ensure the structural adequacy of the existing structure will enable the Council to issue such a Building Certificate.
(b) A structural engineer accredited with Building Professional Board (BPB) submits the following information to Council:-
s A report detailing appropriate tests conducted under the supervision/direction of a structural engineer NPER (National Professional Engineers Register) registered with the Institute of Engineers to evaluate the raft and slab thickness reinforcement size and position and concrete compressive test.
s A certificate of compliance issued by a structural engineer accredited as C7 with BPB is to be submitted to Council that certifies the constructed shed can withstand category 2 wind load and impacts of debris on the shed for all storms up to the 1 in 100 flood event.
Such information shall be submitted within 6 months of the date of this notice, otherwise this consent will lapse.
29 This condition is based on a condition drafted by the expert engineers during the course of the hearing. The applicant proposes that this condition be amended by the addition of the following words at the end of the sentence in the first paragraph of 1(b):
", if any such tests are determined to be necessary by that engineer to certify the structural adequacy of the shed having regard to available documents."
30 The applicant submits that it should be left to the certifying engineer with registration to determine whether any additional testing is required. The Council submits that the appropriately qualified and accredited structural engineer should determine the appropriate test and a report on the testing would provide a basis for the accredited expert to provide the required certification given that they had not observed how the slab and shed were constructed.
31 The Council's draft Conditions of Consent include condition 8:
8. Positive Covenant
Prior to the issue of occupation certificate, a positive covenant benefiting Hornsby Council must be registered on the title to Lot 1 DP 1073144 in accordance with Council's prescribed wording for the following:
(a) Indemnify Council against any claim that ay arise asa result of the erection and use of the shed within an area that has been identified as being ain a high hazard flood area and that would be inundated in a 1 in 100 year flood event.
(b) Require the owners to keep in force in the name of the Owners a public risk insurance policy in an amount of not less than ten million dollars ($10,000,000.00).
(c) Require that in the event that the structure is removed or washed away that it not be permitted to be rebuilt in this location or in an area affected by the 1 in 100 year flood level without further development consent from Hornsby Council.
32 The applicant accepts that a positive covenant is appropriate to notify a subsequent owner of the land as to its obligations to comply with the flood management plan and conditions of consent and keep the shed insured, however it is inappropriate for a subsequent purchaser to be required to give an indemnity to Council against liability.
33 After both parties had provided brief written submissions on the conditions in dispute, Mr Pickup for the Council very properly contacted the Court to draw my attention to the decision of Cowdroy J in Hutchison 3G Australia Pty Ltd v Waverley Council [2002] NSWLEC 151, which is inconsistent with his submissions on condition 8. This decision, and the earlier decision of McClelland J in Galandon Pty Ltd v Narrabri Shire Council (1983) 51 LGRA 5, support the conclusion that condition 8(a) requiring an indemnity would not have a basis in any of the matters set out in s79C of the Act and therefore could not be imposed.
34 In view of my conclusion below that development consent should not be granted, it is unnecessary to express a conclusion on the appropriate wording of a deferred commencement condition.