Information Request MCU21 0212 · MCU21/0212

Officer: 	Patrick Murphy
Direct Telephone: 	07 5329 6436
Our Reference:	MCU21/0212
Your Reference:	0290
18 January 2022
GR Deane & CJ Deane
C/- Pivotal Perspective Pty Ltd
4/59 Mary St
NOOSAVILLE  QLD  4566
[email protected]
Dear
Information Request
Planning Act 2016
I refer to your application and advise that Council requires further information to satisfactorily assess the proposal.
application details
Application No.	MCU21/0212
Street Address:	66 Seaview Tce Sunshine Beach Qld 4567
Real Property Description:	Lot 69 RP 81810
Planning Scheme:	Noosa Plan 2020 (25 September 2020)
INFORMATION REQUIRED
The information requested is set out below:
Issue
Confirmation is required on the western extent and reduced level of the assumed coastal erosion profile used for the geotechnical stability analyses.
There appears to be a discrepancy between the location shown in the report by Royal Haskoning DHV and location adopted for the stability assessment.
The coastal erosion profile adopted for stability analysis is shown on Figure 3 of the Tectonic Report. The extent of coastal erosion is shown to be about 34.5m to the east of the property boundary. Scaling the distance on Figure 17 of the Royal Haskoning DHV report shows it to be about 40m east of the property boundary.

It is recommended that Tectonic be asked to confirm the correct distance to be used for stability analyses.
It is recommended that the value of the reduced level of the base of the erosion area to be used in stability analyses be confirmed. It is noted that Nielsen et al (1992) adopt a scour level of RL- 1.0m for the base of the erosion area. Figure 17 appears to use a value of RL2.64m.

Information Required
Tectonic to confirm the correct distance to be used for stability analyses.
The value of the reduced level of the base of the erosion area to be used in stability analyses must be confirmed noting that Nielsen et al (1992) adopt a scour level of RL-1.0m for the base of the erosion area. Figure 17 appears to use a value of RL2.64m.
Issue
The Tectonic report recommends that footings for the proposed buildings be extended through any fill materials and loose natural soils to found at least 1m into medium dense to dense (or denser) sand.
Depending on the founding conditions exposed after the bulk earthworks are carried out, the report states that it may be possible to adopt a combination of high level and piled footings.
The stability analyses by Tectonic indicate that for this site, the coastal erosion and subsequent re-profiling of the undermined dune slopes will not extend beneath the proposed buildings. Since the potential for shallow footings has been raised, the report should identify any “zone of reduced foundation capacity” that might affect the use of shallow footings. In particular, footings for the proposed buildings in Option 2 would be immediately adjacent to the erosion protection system and would be within the zone of active soil pressure.
Information Required
Identification of any “zone of reduced foundation capacity” that might affect the use of shallow footings.
The potential “zone of reduced foundation capacity” (Neilson et al (1992)) be estimated and marked-up on a plan of the allotment to confirm that the area where shallow footings could potentially be adopted is outside of this zone.
Issue
Table 6 of the Tectonic report provides recommendations for retaining structure design parameters. The values quoted for very loose sand are not consistent with the assumed friction angle and it is recommended that these are checked. The values provided also assume horizontal backfill and it is recommended that this is stated in the report.
Information Required
The recommended design values in Table 6 of the report checked and confirmed.
The commentary to the table amended to state that the values are for horizontal backfill only.
Issue
Section 6.1.3 of the Tectonic report provides recommendations for imported fill.
It needs to be recognised that the recommendations would allow low plasticity clayey soils to be imported onto the site. This may not be the best option given the sandy nature of the foundation soils. If clayey soils were brought onto the site their use would need to be carefully controlled. For example, clayey soils will be less permeable than sand and may create an undesirable barrier to seepage.
Information Required
Further consideration must be given to the quality of material permitted for use as imported fill. If clayey soils are permitted, consideration should be given as to whether there should be any restrictions on their use on the site.

Issue
The site and its immediate surrounds are underlain by very loose to loose sand. The very loose to loose sand extends down the steep dune slope and is almost certain to extend beneath the adjacent allotment and roadway.
Such sands are highly susceptible to vibrations and will experience settlement at very low peak particle velocities. The standard limitations on vibrations that are usually applied to prevent damage to buildings are too high to prevent settlement in very loose to loose sand.
There is also potential for instability of the dune slope as a result of vibration.
Information Required
Careful consideration must be given to restricting the use of vibrating construction equipment on this site due to the potential for instability and settlement of the loose to very loose sands. If the use of vibrating equipment is to be permitted the report must include limits on peak particle velocity and must clearly set out the steps required to carry out a detailed risk assessment of the site and its immediate surrounds.
Issue
Coastal Processes
Information Required
Please submit a revised Coastal Hazards Assessment report to assess potential short term coastal erosion associated with a 500 year average recurrence interval storm event, combined with shoreline recession due to sea level rise for 2100 climate change.  This is required because of the risk to people in an extreme event.  Figure 17 of the coastal hazards report presents result for current climate.  Equivalent work is required for the year 2100 climate change extreme event. Confirmation is required of the total shoreline recession that is estimated to be for the 500 year event in the year 2100, as it is not clear what value was used in the geotechnical assessments.
The revised assessment of extreme event short term erosion under year 2100 climate change conditions with associated shoreline recession should inform the erosion and stability assessments by the geotechnical engineers.
Issue
Geotechnical Investigations
Information Required
Please confirm the actual proposed footing system and erosion protection system to be adopted from the alternate cases described in the Tectonic Geotechnical report of 23 November 2021 in Chapter 6.  Details of the location, depths, spacing and size of the proposed micro-piles and the proposed eastern and side boundary grout curtains are required, and whether side boundary piling is proposed, and if so, details of this piling.  The design must include the protection of the northern and the southern boundaries of the site to prevent erosion on neighbouring properties and exposing the side boundaries of the site to erosion.
Confirmation is required that the stability assessments carried out take account of potential short term coastal erosion associated with a 500 year average recurrence interval storm event, combined with shoreline recession due to sea level rise for 2100 climate change, and confirmation of the efficacy of the proposed footing system.  Confirm the total shoreline recession that was used in stability assessments for the 500 year event in the year 2100, as it is not clear what value was used in the geotechnical assessments.

Details on how vibration damage on adjacent properties is to be managed is required, taking account of the risk of instability on the existing dune slope and the potential for loose sand on the adjacent properties.
Issue
Stormwater
The submitted documentation does not include sufficient detail to address the stormwater runoff from the proposed development. There is no downstream drainage system available and no piped drainage system in Seaview Terrace in proximity of the subject site.
It is noted that the submitted geotechnical investigation includes comments regarding “discharge to Seaview Terrace” and “on site infiltration”.
Information Required
Provide a site specific stormwater management plan for the proposed development. The Plan must be:
prepared by a suitably qualified person (RPEQ - Registered Professional Engineer of Queensland),
be consistent with the recommendations of the site’s Geotechnical Investigation, and
be supported in writing by the author of the site’s Geotechnical Investigation
Discharge of concentrated stormwater onto the dune slope shall be avoided, and under no circumstances shall subsurface disposal of water be permitted using infiltration pits.
Details of how roof-water runoff is to be discharged from gutters, downpipes, driveways and paved areas to Seaview Terrace is required.
Issue – Water Quality and Drainage Code
The application material provided does not properly address the Water Quality and Drainage Code.
Information Required
Provide details demonstrating compliance with the Water Quality and Drainage Code, including how a lawful point of discharge is to be achieved.
Issue
No detail has been provided regarding the proposed access driveway. Council has concerns with the levels/grades of the access driveway and the potential for runoff from Seaview Terrace to travel down the driveway and into the proposed residence
Information Required
Provide a preliminary design of the proposed access driveway. The design must be prepared by a suitably qualified person (RPEQ - Registered Professional Engineer of Queensland) and include but not be limited to:
dimensions, levels and grades,
a longitudinal section extending from the centreline of the road formation in Seaview Terrace to the garage floor,
any works required to maintain runoff from the road formation in the road reserve, and
detail to demonstrate that vehicles will not scrap or bottom out on the driveway or the road formation when entering and exiting the site.
Issue
Site cover
It is unclear as to why the full extent of the lower ground has not been included in the calculation of site cover. Furthermore, the submitted elevation plans and cross sections do not adequately address the area that has been excluded.
Information Required
Reassessment of the lower ground floor site cover inclusive of all areas within the building, with the site cover not to exceed the requirements of the planning scheme.
Elevation plans of the building:
With side boundary fences removed; and
Details of the natural and finished ground levels at the face of the building
Which demonstrate that where excavation is required that the exposed external façade of the building does not exceed 8 metres in building height.
Issue
The site and floor plans include contours however no survey plan has been provided.
Information Required
Please provide a copy of the survey plan.
Issue
Setbacks
It is proposed to construct the lower ground, ground, upper floor and chimney within the front setback. It is noted that there are examples of front setback variations within proximity of the site however these are generally limited to carports and garages with the remainder of the building setback further from the street frontage. The proposed front setback variations are not consistent with the predominant character of the streetscape, impact on the capacity to provide landscaping within the front setback and may obstruct the views of surrounding properties.
A structure is proposed abutting the southern side boundary to accommodate bins and bikes. The wall has a maximum height of 4 metres and is located adjacent to a swimming pool on the neighbouring property to the south. The wall presents unreasonable bulk and will result in overshadowing. The wall is not supported.
Information Required
Provide amended plans which provide for substantially increased front setbacks (except for the garage).
Deletion of the wall situated on the southern boundary (bin/bike store).
Issue
It is proposed to develop 3 storeys contrary to Acceptable Outcome AO7.1 and Performance Outcome AO7 of the Low Density Residential Zone Code. The area is characterised by dwellings with an appearance of 2 storeys. The additional storey is likely to impact on the views of surrounding properties and dominate the street and surrounding area. Furthermore the third storey is also located within the front setback further exacerbating the impact on the streetscape.

Information Required
Deletion of the third storey.
Issue
It is unclear how the proposal complies with Acceptable Outcome AO12.1 and Performance Outcome AO12 of the Low Density Residential Zone Code. Two of the required design elements are not recognisable in the front façade.
AO12.1
Buildings are orientated towards the street by having the main entrance easily recognisable from the street and including two or more of the following design elements in the front facade:
verandahs;
porches;
external stairs;
awning or shade structures; or
window openings.

Information Required
Amend the proposal to demonstrate compliance with AO12.1 and PO12 of the Low Density Residential Zone Code.
Issue
The proposal does not comply with AO20.2, AO20.3 and PO20 of the Low Density Residential Zone Code. The roof form and slab on ground construction methodology means the development is not responsive to the topography of the site and will dominate the surrounding landscape.
Information Required
Amend the proposal to demonstrate compliance with AO20.2, AO20.3 and PO20 of the Low Density Residential Zone Code.

due date for response to information request
The due date for providing the requested information is 22 April 2021. Email your response to [email protected]. Please advise Council of your response to this information request in accordance with section 13 of the Development Assessment Rules.
If you do not provide a response before the due date, it will be taken as if you have decided not to respond to the information request and Council will continue with the assessment of your application.

other details
You can follow the progress of this application online at www.noosa.qld.gov.au. The “Online Services” page can be accessed via "Quick Links" on the left hand side of the screen.
Should you have any further queries in relation to the above, please do not hesitate to contact me on the number above.
Yours faithfully,

Patrick Murphy
Coordinator Planning

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PO Box 141		P. (07) 5329 6500	[email protected]	
	TEWANTIN  QLD  4565	F. (07) 5329 6501	www.noosa.qld.gov.au
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