I object to SSD-86017721 as key impacts do not yet appear demonstrated as manageable or in the public interest. The proposal introduces an eight-storey building, removes 27 mature trees and increases density, traffic, excavation and stormwater load, yet no cumulative modelling has been provided to show Rose Bay can absorb this alongside the substantial redevelopment pipeline created by recent LMR reforms, which is already material and expected to continue. Although the proposal meets LMR requirements by providing 11 affordable dwellings for 15 years, this is a temporary benefit against permanent environmental and infrastructure impact. There also appears to be no transparent hazard classification, and groundwater/ASS risk remains unresolved. Based on my understanding, s4.15 still requires cumulative impact and public interest assessment even under LMR reform. Given the high private value of redevelopment in this location, evidence-based oversight appears essential. I request refusal unless cumulative impact, risk controls and public benefit can be clearly demonstrated.

Submission – Objection to SSD Application for 23–31 Dover Road, Rose Bay

To whom it may concern,

I am a long-term resident of the Rose Bay and Vaucluse area and am writing as a concerned local community member who uses Dover Road on a daily basis. I am familiar with this part of Rose Bay and, while I appreciate the need for more housing in Sydney, I am very concerned that this particular proposal is far beyond what this site and surrounding streets can safely accommodate.
My comments focus on the issues that are most obvious to me as a local resident: traffic and access, cumulative development pressures, flood and groundwater risks, and the scale of excavation proposed for a site that already has known geotechnical constraints.

1. Traffic, Access and Cumulative Impacts
Anyone who lives in the eastern suburbs knows that our local road network is extremely limited. Dover Road in particular carries school traffic, buses, pedestrians, construction vehicles and local cars throughout the day. Even small developments can have a noticeable effect here; a development of this size will have a major one.

What concerns me most is that the traffic assessment appears to treat this building in isolation, rather than as one of many developments happening at the same time in this small pocket of Rose Bay. There are multiple LMR sites under construction or proposed in the area, as well as at least three large-scale State Significant Developments, including this one. All of these will ultimately funnel into the same constrained intersections.

The Transport Impact Assessment for this project seems optimistic about the capacity of the road network and does not reflect the level of congestion locals already face — particularly during school pick-up and drop-off times, on weekends, and whenever there is construction activity. Simple trips regularly bank up along Dover Road and Old South Head Road even without major works occurring.

Construction traffic is another major concern. Excavating two full basement levels will involve removing a very large amount of earth, which means months of continuous truck movements along a narrow road that already struggles with visibility and parking. The Preliminary Construction Traffic Management Plan is extremely light on detail for a development of this magnitude.
Without a traffic study that looks realistically at the combined effect of all current and proposed developments in this part of Rose Bay, I do not see how the impacts of this building can be properly assessed.

2. Flood Risk and Emergency Access
After reading the Flood Impact and Risk Assessment (FIRA), I was genuinely shocked at how serious the flood conditions are on this site. The study shows that this part of Dover Road acts as a floodway in storms, with water flowing directly across the road and over the site in major events. The predicted depths and the speed of water movement are significant enough that evacuation is considered unsafe.

The recommendation for residents to “shelter in place” during a flood event is deeply concerning. For a building of this size, with basements, underground car parking and lifts, this seems like an unacceptable risk. Water can move through this area quickly in heavy rain, and we have had unpredictable storm events and flash flooding in Rose Bay in the past. Adding a large basement structure into a mapped floodway feels fundamentally at odds with public safety.

I also note that adding a deep basement can change how water flows across a site. This is not properly considered in the EIS. There is also no meaningful assessment of how a structure of this scale might redirect or worsen overland flow for nearby homes, particularly those on the lower-lying parts of Wilberforce Avenue.

This is an issue that cannot be dismissed, and from my reading, it has not been addressed adequately.

3. Groundwater, Dewatering and Excavation Risks

The documents acknowledge that groundwater is present across the site and that the proposed basement will extend into these saturated soils. The Dewatering Management Plan appears to assume that long-term pumping and impermeable walls will resolve the issue. However, there is little explanation of how surrounding homes will be protected from settlement, groundwater drawdown or changes in soil moisture.

The local area has a mix of older homes, duplexes and small apartment buildings — many of which were not designed with deep excavation next door in mind. The Geotechnical Report identifies layers of fill and loose alluvial material above rock, which is exactly the type of soil profile that can be destabilised by large changes in groundwater conditions.

What stands out to me is that there is no cumulative analysis. With so many other basement projects within a few blocks, the combined effect on groundwater has been completely overlooked. Water does not respect property boundaries, and treating each development as an isolated event is unrealistic and potentially unsafe.

For a site already identified as flood-affected and groundwater-constrained, the scale of excavation proposed feels excessive.

4. Noise, Vibration and Construction Impacts

The Noise and Vibration Assessment acknowledges that excavation will involve rock breaking, piling and other high-impact activities. Many homes surrounding the site are older or lightweight construction, and even minor vibration can cause cracking. The mitigation measures seem generic rather than site-specific and rely heavily on monitoring rather than prevention.
Given the density of existing housing around this site, construction impacts will be felt intensely by neighbours for an extended period. This is something that residents should not be expected to simply absorb without stronger and more reliable safeguards.

5. Scale, Height and Tree Loss

This part of Rose Bay has always been a low- to mid-rise area with a more modest built form. The jump to an eight-storey building is enormous and will fundamentally change the feel and amenity of Dover Road and Wilberforce Avenue. The visual impact diagrams show how dominating the building would be relative to nearby houses and are jarring in appearance even on paper.

The loss of mature trees is also concerning. Larger established trees take decades to regrow and play an important role in shade, cooling and stormwater absorption — particularly in a street with known flooding issues. Replacing them with smaller podium-level planting is not equivalent in function or environmental benefit.

Conclusion

I understand the need for well-designed housing and I am not opposed to redevelopment on this site. However, in its current form, this proposal is too large, too intensive and too risky for a location with known flooding, groundwater and traffic constraints. For these reasons, I respectfully object to the development in its current form.

I would be open to supporting a smaller and more appropriate-scale building, provided that any future proposal is accompanied by thorough and transparent assessments of traffic, groundwater, dewatering, flood behaviour, stormwater capacity and cumulative impacts. Importantly, these assessments need to consider all other current, approved and proposed developments in Rose Bay, so that the combined load on local infrastructure, the road network and the surrounding environment is properly understood.

Please see attached pdf document

We are writing to express our concerns / objections relating to SSD-86017721.

• The applicant seeks 66 parking spaces for 49 dwellings. We understand that the limit is 0.5 per dwelling, in which case the development should have no more than 24 parking spaces.
• The site is flood-prone with shallow soils and acidic soils. This poses risk to Rose Bay beach, which is already heavily polluted.
• An appendix states that subsidence at on neighbouring properties will no more than 200 mm. That amount of subsidence could cause major damage to adjacent dwellings, not to mention infrastructure such as stormwater and sewage pipes.
• The application states that groundwater monitoring will be reported no more than 60 days after project completion. It should be reported real-time, otherwise this delayed reporting is a waste of time.
• Construction includes a perimeter sheet pile wall to 3 metres below excavation level. That will divert ground to either side of the development and threaten adjacent properties. There is a substantial amount of ground water that flows into the area in the very long slope (about 1 km in length) from north Rose Bay. We do not see any discussion of where that water will go.
• There is no assessment of this development in the context of multiple other developments in train for the same area (boundaries of Dover Rd, Wilberforce Ave and Spencer Lane, totalling about 16,000 m2.
• The applicants state (Appendix E, p. 7) that “mitigation measures have been identified to address the community feedback”. Such mitigation measures are not specifically listed in the application.

Per attached objection letter

1 The site is in the very high risk, low-lying Rose Bay settlement area, and is thus totally unsuitable for a development with excavation for parking. The water table of this site is very high, the soil is soft (considered "very loose to loose sands"), and there have been structural damage issues in nearby existing buildings caused by previous shallower excavations nearby.
2 The two-storey excavation would be well into the groundwater, increasing existing uplift pressure, and further altering water flows. This would be in addition to other proposed excavations in the immediate vicinity, and there has been no study of the cumulative impacts of multiple deep excavations on groundwater and land stability. There has, however been known damage to land stability and nearby properties caused by shallower one-storey excavations. Deep excavations will exacerbate existing basement flooding and inundation, which is already problematic in this low-lying area, including in buildings in my street.
3 Buildings in this area have already suffered structural damage and flooding. More excavations in this area will undoubtably increase the incidences of damage to existing buildings.
4 Acid Sulphate Soil ASS (Class 4) Risk. There is a risk of release of acid/contaminants into the aquifer and harbour, with excavations of more than 2 metres . The proposed excavation is 7-8 metres.
5 Consultant reports are developer-funded and contain disclaimers. There is no protection for surrounding impacted properties.
6 SEPP uplift (LMR) is PROHIBITED on high risk-land. This site is high-risk based on its geotechnical instability, cumulative excavation risk, affected groundwater, and it has been mapped as a high-risk floodway. This development should thus be PROHIBITED.
7 The proposed development, in particular its excavation for parking, is not in the public interest. It is foreseeable that it would cause irreversible damage to the local environment and nearby properties, and thus it is unacceptable.

I have lived in Rose Bay for 21 years and love living here. I support safe and considerate development but I cannot support the proposed development at 23-31 Dover Rd. This development sits on vulnerable land with Acid Sulphate Soil and on shallow groundwater table and the excavation that is proposed will cause significant damage to surrounding properties.
My home has suffered cracking on 3 separate occasions when developments were undertaken a few hundred meters away and I am concerned this could occur again with this current development.
Not only is there a geological concern but Rose Bay does not have the appropriate Infrastructure to cope with the proposed increase of residents. Rose bay sits on a Peninsula and cannot cope with the current level of traffic. There is no room to implement a dedicated Bus Lane or to introduce Light Rail. The closest train station, Edgecliff, is 4km away with a 1hr walk and the buses are going to get caught in horrendous traffic if the amount of development that is proposed goes ahead.
Please do not approve this DA as it will set a precedent to other proposed developments that Rose Bay cannot cope with.
Grow Rose Bay the Safe Way.