HOT OFF THE PRESS: The Batemans Bay Bridge Replacement Review of environmental factors submissions report by Roads and Maritime Services | May 2018 The 422 page report is now available and makes very interesting reading. Roads and Maritime Services is proposing to construct a new bridge on the A1 Princes Highway over the Clyde River at Batemans Bay. The Batemans Bay Bridge replacement (the proposal) includes a new four lane bridge, two lanes each direction, to the west of the existing bridge and removal of the existing bridge. The proposal would improve access to Batemans Bay and surrounding areas, allow access for larger trucks, reduce traffic delays and improve the Kings Highway / Princes Highway intersection. The main issues raised in submissions for the proposal, by the community included the height of the new bridge, retention of the existing bridge, proposed changes to local roads and the Kings Highway / Princes Highway intersection, as well as foreshore works. Issues in regard to operational noise were also raised by the community.
Agency submissions related primarily to the sensitivity of the receiving environment, with the key issue raised being water quality during construction and operation. Over half of the submissions received commented on elements of the proposal design. In the summary below for those who are time poor to read the whole document we present the major elements regarding the Bridge A second summary will look at traffic. •Issue: The proposed bridge height is too low, a navigational clearance of between 14 and 20 metres would be preferred to accommodate larger vessels and allow boat access upstream. Response: The proposed 12 metre clearance would provide uninterrupted access for around 90 per cent of existing boat movements in the area. A range of navigational clearances from seven metres to 23 metres were considered in development of the proposal. Clearance of seven metres would not provide access for the majority of vessels known to use the area. The higher navigational clearances (14 metres, 18 metres and 23 metres) were not pursued as bridge approaches either side of the river would need to be lengthened to achieve the required grade. This would result in additional property acquisition and biodiversity impacts, as well as adverse urban design outcomes. •Issue: The existing bridge should be retained for its heritage and aesthetic value. Alternatively, components of the bridge should be retained for use as a fishing platform, fish habitat or as a diving wreck. Response: The existing bridge would be removed to provide improved access to the Clyde River and Batemans Bay for vessels. Removal of the existing bridge would also offer improved public access to the foreshore on the north and south riverbanks providing opportunities for new community spaces. Leaving the bridge in place as a pedestrian bridge or other tourist feature would require the lift span of the bridge to remain closed resulting in boats with a height over 3.5 metres not able to travel under the bridge. The existing bridge is in poor condition and would require ongoing costly maintenance. •Issue: The proposed changes to the Kings Highway / Princes Highway intersection would not be adequate. Design alternatives such as slip lanes or an overpass should be considered. Response: In response to submissions, additional design and traffic modelling investigations were carried out using peak holiday traffic data to review the suitability of design options against the heaviest traffic conditions. The additional investigations identified that the provision of left slip lanes on the Princes Highway northbound to the Kings Highway and on the Kings Highway to the Princes Highway northbound would provide additional benefit. As such, this design change is proposed to be implemented (refer to section 4.1of this submissions report). The construction of an overpass would result in a substantial increase in cost and is not proposed. • Issue: Ramps from the Princes Highway at Clyde Street should be included in the proposal to enable better access to Clyde Street and to avoid traffic issues on North Street. Response: Ramps on the Princes Highway to and from Clyde Street are not proposed as they would cause safety issues, property impacts, and increased impacts to SEPP 14 wetlands and would require additional infrastructure on the southern foreshore. Traffic modelling has shown that the intersection of North Street and the Princes Highway would operate at least at a level of service (LoS) B during peak holiday periods, meaning traffic flow is acceptable with cars travelling at their desired speed Biodiversity An additional biodiversity assessment report was prepared to clarify the vegetation communities present in the north of the study area and the potential impacts of the proposal. This assessment identified that up to 0.12 hectares of the Illawarra and south coast lowland forest and woodland critically endangered ecological community (CEEC), listed on the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) would be impacted by the proposal. An assessment of significance completed for this impactconcluded that the proposal would be unlikely to have a significant impact on this critically endangered ecological community. Impacts to this community would be offset in accordance with the Roads and Maritime Guideline for Biodiversity Offsets. Design changes In response to submissions and following further design development, a number of changes to the REF proposal were identified. No changes were required to the EIS proposal. In response to submissions, design changes are proposed to the Princes Highway intersections with the Kings Highway and North Street. These changes comprise: •provision of left slip lanes on the Princes Highway northbound to the Kings Highway and on the Kings Highway to the Princes Highway northbound to assist in reducing congestion at this intersection, particularly during peak periods •minor kerb realignment and removal of three on-street parking spaces on North Street at the intersection with the Princes Highway to enable safe turning movements by heavy vehicles up to 19 metres long, including semi-trailers and buses. Further design changes are proposed due to design progression since display of the REF. These changes comprise: • widening of Old Punt Road between Wray Street and the northern foreshore to enable safe two-way traffic • further development of construction methodologies, including use of temporary construction jetties, removal of piles to varying depths below the riverbed, potential for use of driven piles and changes to construction equipment • further development of supporting utility and road work, including utility connections and pavement tie-in work. Need and justification for the proposal The respondents to in their submissions to the RMS call for community feedback stated that money for the replacement of the Batemans Bay Bridge should be spent on 'better' meaning projects. Response The replacement of the Clyde River crossing is regionally important as the Princes Highway is a critical link for both passenger and freight transport between the NSW South Coast, Canberra, Illawarra and Sydney regions. The existing Batemans Bay Bridge is in need of repair or replacement in the medium to long term and has the potential to be deemed unsafe for use or require the introduction of further weight restrictions for heavy vehicles. Due to the lack of alternative routes, unavailability of the Clyde River crossing would result in substantial detours between the NSW South Coast and north of Batemans Bay, resulting in travel times of between two and a half and four hours. The loss of this key route would potentially result in economic impacts on the NSW South Coast region due to its importance for both the tourism and freight industries. The new bridge would allow an increase in higher mass limits which would support economic growth and productivity. The aim of the proposal is to improve connectivity between north and south Batemans Bay and along the Clyde River. In particular, it would: •improve freight access by enabling larger trucks across the bridge particularly semi-trailers and B-doubles (would improve reliable access to markets for businesses in Batemans Bay, would improve access to products for the Batemans Bay community providing economic and social benefits) •address current poor bridge condition and reduce ongoing maintenance and major rehabilitation obligations resulting in improved connectivity and reduction in traffic delays •improve local and regional network connectivity for motor traffic (improving access to Batemans Bay CBD for residents on the north side of the bridge, including access to basic services such as medical and emergency services. improving access for residents to regional services in Nowra and Canberra, improving access for tourists to Batemans Bay which is a large industry in Batemans Bay) •improve journey reliability, particularly during holiday seasons (without the need to raise a lift span for maritime vessels, highway traffic would be more reliable and would avoid traffic delays as traffic waits to cross the bridge - particularly at the Kings Highway / Princes Highway intersection). Roads and Maritime recognised that the community strongly identifies with the existing bridge through its character and historical significance. A community survey to inform the REF found that about 35 per cent of respondents believe the existing bridge contributes to neighbourhood character and identity of the town of Batemans Bay. Lift span operation of the existing bridge is an impediment to the efficiency and consistency of traffic flow and journey reliability. Regular network severance and consequent traffic build up and delays are caused by scheduled morning and afternoon lift span openings. During the Christmas and New Year period, northbound and southbound queues to the bridge take around one hour and 45 minutes to clear after the lift span has opened for marine traffic Severance of the network and delays can have substantial implications given the large residential areas, commercial activity and emergency service requirements on both sides of the river. When the lift span fails, interruption to highway traffic means that people are cut off from basic services including medical and emergency services and businesses are cut off from markets and products. For regional communities, highway traffic interruption affects access to key regional towns and interstate freight movements. In the past five years, there have been numerous failures of the lift span that have resulted in long delays, with the only available alternative route being around a 360 kilometre journey. As a result of these failures and to provide a long-term benefit to local and regional communities, the existing bridge is to be replaced to provide improved connectivity and journey reliability. One of the objectives of replacing the Batemans Bay Bridge is to improve freight access by allowing larger trucks and B-double heavy vehicles up to 26 metres in length across the Clyde River. This initiative is identified within the Princes Highway Corridor Strategy to address the NSW Long Term Transport Master Plan objective of improving road productivity to promote economic growth. The Princes Highway serves as the main transport corridor providing freight and passenger movements to and from the Illawarra and South Coast regions. As well as providing improved freight access through the regions, the proposal would also improve freight access to urban centres along the highway, including Batemans Bay. Improved freight access could assist in local business deliveries as well as enabling local businesses to more efficiently dispatch goods to regional, national and international markets. The bridge renewal option would also meet some of the proposal objectives, however it would have the following disadvantages: •would not remove the operational height and width constraints of the existing bridge •as the existing bridge and lift span mechanism ages, there would be increasing maintenance costs (above what is currently expended) •extensive period of disruption with temporary bridge closures and periods where the lift span would remain closed impacting on marine vessels •the cost for the works would be high and the program lengthy due to the complex nature of the works. Bridge replacement was selected as the preferred alternative as it would: •enable the use of the Batemans Bay Bridge by higher mass limit (HML) heavy vehicles •lower maintenance costs compared to the existing bridge •improve the reliability of the river crossing by increasing the bridge capacity and allowing most marine vessels to pass under the bridge without use of a lift span. The workshop recommended the western option as the preferred option as it: •provides the best connectivity and functionality •provides better opportunities for parking to support CBD growth and foreshore access •provides the greatest flexibility in terms of options for construction •has superior geometry (for better safety) •allows a better driver experience that is more visually appealing •would lead to better pedestrian accessibility •provides better opportunities for parking and boating facilities on the northern side of the river. The central option was identified as being more difficult to construct, with a pier and abutment to be built on the existing Princes Highway alignment. This would require more extensive temporary roadworks to maintain the Princes Highway in operation during construction The respondents stated that the pier and girder design of the new bridge is not a suitable design and an arch structure spanning across the river should be built. Response The new bridge has been designed to have larger spans to minimise the number of piers in the river to minimise potential environmental and maritime traffic impacts. In addition, a range of measures would be implemented to minimise biodiversity, water quality and marine traffic impacts on the waterway caused by the construction of the bridge (refer to Chapter 6 of this submissions report). A structure with no piers in the river, known as a clear spanning concrete arch structure is not suitable due to the lack of available space either side of the river to construct such a structure. The lack of space is due to the bridge alignment and the need to connect to existing infrastructure as well as a number of environmental constraints including the SEPP 14 wetland area at the southern end of the proposal area. The bridge has been designed in accordance with relevant Roads and Maritime urban design guidelines. Navigational clearance A number of respondents noted that the proposed 12 metre navigational clearance of the new bridge would not allow for many boats to pass upstream to the Clyde River. A clearance between 14 metres and 20 metres would be preferred to accommodate larger vessels and allow boat access up stream. There has been a lack of consideration to future river use and the limitations further upstream. Response As described in section 2.4.4 of the REF, the design development process considered a range of navigational clearances from seven metres to 23 metres. These were considered against evaluation criteria. Based on this evaluation, the lower navigational clearance of seven metres was not pursued as it would not provide sufficient clearance for the majority of vessels. The higher navigational clearances (14 metres, 18 metres and 23 metres) were not pursued as bridge approaches either side of the river would need to be lengthened to achieve a maximum grade of less than five per cent for pedestrians including those with limited mobility. This would particularly impact on the Kings Highway / Princes Highway intersection. These options would also result in adverse urban design outcomes and visual impacts. The increase in height of the bridge from 3.6 metres to 12 metres would provide uninterrupted access for vessels that can pass under a navigational clearance (MHWS) of 12 metres. The 12 metre navigational clearance has considered tides, storm surge and sea level rise. A boat study undertaken as part of the proposal (summarised in section 6.7 of the REF) identified that the forecast future maritime trends suggest that vessel lengths and the number of long vessels are increasing, however, the growth in powered vessels is higher than the growth in yachts. While there is expected to be a growth in vessels over six metres in length, this would be at a slower pace than overall boat numbers. This would mean that the proportion of yachts is expected to decrease compared to the growing prevalence of powered boats which have lower clearance requirements. The boat study found that the proposed 12 metre clearance would provide uninterrupted access for around 90 per cent of existing boat movements in the area. This includes all current commercial operators and the majority of vessels using the current bridge lift span, including double storey houseboats and most yachts. This would increase the proportion of maritime users that would have uninterrupted access upstream of the proposed Batemans Bay Bridge. In addition, further upstream of the new Batemans Bay Bridge is an overhead electrical river crossing. These electrical cables have a safe navigational clearance of 15 metres MHW (mean high water). A higher bridge clearance that would allow taller marine vessels to pass under the bridge would be of limited benefit as they would not be able to travel underneath the powerlines. As part of the proposal, the T Wharf would be replaced to allow for a range of vessels to be moored to access the CBD. Bridge removal A number of respondents stated that the existing bridge should be retained for its heritage and aesthetic value as it is a tourist attraction, encourages businesses to use the bridge and hold special events. A respondent suggested that the existing bridge could be used as a pedestrian crossing of the river. A suggestion was also made that to keep the existing bridge, tourist boats should change to be “low profile”. Response The existing bridge would be removed to provide greater uninterrupted access to the Clyde River and Batemans Bay for vessels. Leaving the bridge in place as a pedestrian bridge or other tourist feature would require the lift span of the bridge to remain closed resulting in boats with a height over 3.5 metres not able to travel under the bridge at any time. The existing bridge is in poor condition and would require ongoing costly maintenance. Removal of the existing bridge would also offer improved public access to the foreshore on the north and south riverbanks providing opportunities for new community spaces.Roads and Maritime would prepare and implement a heritage interpretation strategy (environmental management measure NAH4). Roads and Maritime would liaise with Council and stakeholders as to whether there are any parts of the existing Batemans Bay Bridge which could be salvaged. The bridge name plates and memorial plaque would also be salvaged. You can read the full 422 page report HERE
