Ella Bay Road Design and Environmental Management Report
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Ella Bay Integrated Resort Proposal SEIS Submission Response Volume Four Ella Bay Road Design and Environmental Management Report Executive Summary This report is a road and environment design document with a primary aim of providing information for approvals under the EPBC Act and Wet Tropics Management Authority (WTMA) permit for Satori Resorts Ella Bay Pty Ltd for the action Ella Bay Integrated Resort Development Proposal (EPBC 2005/2159). The report provides the design and key environmental values for the proposed upgrade of Ella Bay Road from Flying Fish Point to Ella Bay. It is based on work completed for the EIS, and Supplementary EIS and subsequent studies contained in the SEIS Submission Response. The report summarises all relevant design and environmental advice and sets out the design criteria Ella Bay Road upgrade is required to provide suitable level of access for the Ella Bay Integrated Resort Development. Ella Bay Road is a long established gravel road which services the Seahaven Prawn Farm, visitors to Ella Bay National Park and access to Ella Bay property with a length of approximately 4km. The road winds through World Heritage Area Zone C around Heath Point Headland and is under the control of Wet Tropics Management Authority for construction and management approvals of the World Heritage Area (WHA) section. This report provides detailed road and environmental design covering road alignment, cross- section, clearing envelope, storm water treatment, fauna and flora mitigation and monitoring, and operational management and monitoring. Road concept and staging The road implementation differs from that proposed in the EIS & SEIS; Stage 1 of Ella Bay Road upgrade will be completed at the start of the Ella Bay Development and Stage 2 Flying Fish Point Bypass will be initiated once a trigger point of 1,000 vehicles per day has been reached. The road alignment chosen in the SEIS; Option D has been retained and further refined. The Multi Criteria Analysis presented in the SEIS selection of options has been reviewed and confirmed as the most appropriate option. The road traffic generation has been revised and confirmed within 10% of that presented in the EIS & SEIS. The reports are attached in the Appendix 2 & 3 of this report respectively. Stage 1 comprises a 4000 metre upgrade of the existing Ella Bay Road from Ruby Street in Flying Fish Point to the entry of Ella Bay Development. The road will be required to carry up to 1,000 vehicles per day prior to the commitment of stage 2. The road will be constructed to the full width as part of Stage 1 works. Stage 2 will comprise a new 880m road that bypasses Flying Fish Point to the west, Stage 2 will include construction of a roundabout and approaches on Bay Road to direct Ella Bay traffic north behind Flying Fish Point through a new tunnel, and connection to the existing Ella Bay Road alignment to the north of Ruby Street. The road will then follow the existing alignment to Ella Bay. The critical event of evacuation has been taken into account with the elevation of the road to a minimum of 5m AHD of which is approximately 2.5m above the 100 year ARI, Global Warming inundation levels. Environmental Significance and Potential Impact to WHA The Ella Bay Road study area is considered to be of National Significance for nature conservation. It supports a high diversity of terrestrial flora and fauna of conservation significance as well as important populations of Southern Cassowary (Casuarius casuarius Ella Bay Integrated Resort Development SEIS Submission Response Volume 4 ii Ella Bay Road Design and Environmental Rep. johnsonii), the Common Mist Frog (Litoria rheocola) and potentially the Torrent Tree Frog (Litoria nannotis), and Australian Lacelid (Nyctimystes dayi). The potential unmitigated impacts of the proposed access road and the effectiveness of mitigation measures on the site have been assessed. Extensive mitigation measures have been proposed to minimise this impact on fauna especially the cassowary. The complete set of these mitigation measures have not been trialled previously with cassowaries although the methodology is commonly used with other fauna. The proponent has initiated a number of studies and trials of elements of the mitigation: Cassowary fence and escape gate trials and surveys of cassowary usage of underpasses. The mitigation will also include fauna underpasses (culverts with fauna furniture) for smaller animals (macropods, amphibians, understorey and ground dwelling fauna) in order to minimise the barrier effects. Frog-exclusion fencing will be included within 25m of streams to reduce possible road mortality. The Ella Bay Road passes through Ella Bay National Park and World Heritage Area through the Heath Point headland which provides magnificent views of the coast line and to Ella Bay. The scenic values of the Wet Tropics Queensland and Great Barrier Reef World Heritage Areas will be showcased with the road upgrade. A Visual Landscape Analysis has concluded that the visual impact of the road widening and upgrade of the road, with incorporated visual impact mitigation measures, is unlikely to adversely affect the scenic values of the World Heritage Areas and in most cases the visual amenity will be improved through dust suppression and endemic revegetation strategies. The conclusion of the multi criteria assessment is that providing the design and mitigation strategies that are described in this report are implemented the proposed road upgrade will not have a net adverse impact on the integrity of the World Heritage Area. Road Design and Design Criteria Ella Bay Road will be designed to reduce the impact of edge effect on the rainforest by minimising clearing and retaining mature trees where possible. The road will be revegetated to seal the edge of the rainforest and prevent weed incursion. The road is expected to convey a maximum design daily two way traffic of 4,138 v/d with an annual average daily traffic (AADT) of 3,134 v/d. The maximum design hourly two way traffic is 350 v/h. The roadwidth chosen for the recommended speed of 60km/h is a sealed pavement width of 10.0m comprising 2 x 3.5m lanes with a 1.5m delineated sealed shoulder each side. This is based on Austroads single carriageway road widths where narrower lanes or shoulders are suggested based on: . The preservation of flora and existing edge sealing forms stringent controls preventing wider lanes; . The road speed is restricted to 60km/hr; . There will be little truck traffic except for servicing the resorts; and . The lane width is consistent with other roads in the World Heritage Areas. Localised widening of both the laneway and shoulder will be required where horizontal curves are less than 119m radius. The 1.5m wide shoulder is suitable for use as a bikeway and will be delineated to provide a bicycle lane in both directions. Extensive traffic calming comprising delineated roadside shoulders, cassowary signage, transverse line markings, chicanes and raised speed platforms will be used to reduce the operational speed. The bike lane and traffic calming will be used to support the “change of focus” as people enter the Ella Bay area. Ella Bay Integrated Resort Development SEIS Submission Response Volume 4 iii Ella Bay Road Design and Environmental Rep. Localised “pull off” lanes of 2.5m total sealed shoulder will be provided for service vehicles and for discretionary stopping of cars. The road widening will be located near mitigation features for servicing and monitoring e.g. fauna bridge, fauna culverts and escape gates. Preliminary design investigation has established that stopping sight distances, and manoeuvre sight distances will be compromised in some locations requiring reshaping of embankments with minor additional clearing and revegetation with low height species. A noise study has determined that the predicted peak hourly noise levels of Ella Bay Road will be more than 7dB(A) less (quieter) than the current Kuranda Range Road at 10m from the centre of the lane. At 33.5m it is predicted to be equivalent to the peak hourly noise level for the Kuranda Range Road at 100m. Hydrology, Catchment Integrity and Water Quality The road cross-section has been designed with a 3% one-way fall towards the east so that upstream flows emanating from heavily vegetated rainforest will be able to bypass contamination from road runoff by transport in table drains to culverts on the western side of the road. On the eastern side, the road runoff will be treated for gross and fine particulates removal with sensitive areas incorporating bioretention swales for treating soluble toxins from first flush road runoff. Table drains will be lined with vegetation and geo-fabric or concrete in steeper areas to prevent erosion. The culverts along Ella Bay Road will be changed from concrete pipe culverts and replaced with concrete box culverts and riprap discharge apron will be provided to prevent erosion. There will be three bridges along Ella Bay Road including a dedicated fauna underpass over a small drainage line. Where Ella Bay Road crosses two creeks, bridges will be constructed instead of culverts to provide cassowary fauna underpasses. The bridges have been sized for cassowary use and will far exceed the hydrological flow requirements. Visual Values Ella Bay Road has significant visual values along the majority of the road from Flying Fish Point to Ella Bay and encompassing the WHA of Heath Point. The alignment of Ella Bay road is located adjacent to and passes through the Wet Tropics WHA within a sensitive visual catchment which exhibits moderate to high levels of visual sensitivity. A landscape integration strategy has been prepared to provide safe travel for the public between Ella Bay and Flying Fish Point whilst retaining the natural visual sensitivity and catchment values.