Dunsborough region boating facility planning study SUMMARY report

Transcription

1 Dunsborough region boating facility planning study SUMMARY report for City of Busselton. April 2014 FINAL Report SCR1401

2 Executive Summary The purpose of this overall study was to identify a preferred site for a new regional boat ramp facility in the Dunsborough region. The following studies were undertaken as part of this project: Planning (City of Busselton) Report 1 Wave Modeling (APASA) Report 2 Initial Community Engagement (Carolyn Walker) Report 3 Vegetation Assessment (Onshore Env) Report 4 Preliminary Designs, Coastal Processes and Boating Demand Assessment (MRA) Report 5 Second Community Engagement (Carolyn Walker) Report 6 This study has identified a technical preferred (Quindalup Pro Fish) and community preferred (Locke estate) site within Geographe Bay, and developed a concept for a sheltered boat launching facility at Canal Rocks. This has resulted from substantial stakeholder engagement and technical studies that have reduced nine potential sites down to a shortlist of three. It has also identified further studies required to confirm the viability of a potential boat ramp at each of these three sites. Analysis of boating demand indicated that there is demand for several boat ramp facilities in the region if sites can be found. This study therefore recommends further investigations, design and approvals to confirm the viability of two boat ramps in the Dunsborough region, specifically: 1) On the Geographe Bay coast, a two lane boat ramp with associated finger jetty and trailer parking at either Quindalup Pro- Fish (recommended by technical experts) or adjacent to Locke Estate (preferred by community stakeholders). 2) On the West Coast, construction of a breakwater at the existing Canal Rocks boat ramp and associated upgrades to the parking and facilities. Studies required to confirm the viability of the proposed sites include: 1) Further analysis of the safety of craft entering and leaving a breakwater at Canal Rocks. 2) A survey of boat ramp users to confirm if ramps at each location would be widely used given actual boat user behaviour. 3) More detailed environmental studies and planning, especially where the facilities would result in the loss of peppermint woodlands (adjacent to Locke Estate and, to a lesser degree, Quindalup Pro- fish). 4) A Marine Precinct Plan for the Quindalup Pro- fish site to determine the effect of a potential ramp on existing users. 5) General Community Consultation. 6) Consultation with the government departments, including DPAW and DoT. The outcome of these additional studies would allow the project to progress to applying for the necessary approvals and preparing detailed designs. ii

3 Table of Contents 1 INTRODUCTION BACKGROUND DEMAND FOR A NEW FACILITY INITIAL SITE IDENTIFICATION (9 SITES) PLANNING ASSESSMENT WAVE MODELLING HYDROSURVEY INITIAL STAKEHOLDER CONSULTATION DETAILED INVESTIGATIONS (4 SITES) VEGETATION STUDY ABORIGINAL HERITAGE REGISTER COASTAL PROCESS ANALYSIS AND PRELIMINARY DESIGN REVIEW AND COUNCIL BRIEFING FURTHER STAKEHOLDER CONSULTATION RECOMMENDATIONS STUDY OUTCOMES WAY FORWARD GLOSSARY REFERENCES

4 Acknowledgements This planning study has been part funded by grants from the Department of Transports Recreational Boating Facilities Scheme (Round 16) The technical studies which form the basis of this summary report were undertaken by a number of consultants for the City of Busselton including MP Rogers and Associates APASA, Onshore Environmental, and by Strategic Planners for the City. Community engagement was undertaken by Carolyn Walker Public Relations and Estill and Associates (Linton Pike). Limitations of this Report This report and the work undertaken for its preparation, is presented for the use of the client. The report may not contain sufficient or appropriate information to meet the purpose of other potential users. Shore Coastal does not accept any responsibility for the use of the information in the report by other parties. Rev Issues Description By Review Date A Draft report ML SB/CoB 12- Mar B Final Report ML/OS SB 08- Apr

5 1 Introduction City of Busselton 1.1 Background The Capes Regional Boating Strategy (Shore Coastal 2011) identified the need for additional capacity for recreational boat users in the Dunsborough Area. In response to this, numerous improvements to existing facilities recommended under the strategy have recently been constructed utilising grants from the Rounds 16 and 17 Regional Boating Facilities Scheme including: Abbey Boat Ramp Upgrades: 2 lane ramp, finger jetty, overflow parking. Quindalup (Sea Rescue) Boat Ramp: ramp extension, trial sand trap, overflow parking. Old Dunsborough Boat Ramp: finger jetty. Gracetown Boat Ramp: carpark upgrade. Gnarabup Boat Ramp: carpark upgrade. Georgette St and Dolphin Road: seasonal boat ramps. However, the Capes Regional Boating Strategy and other studies indicate that the current facilities will not be able to meet both current and future recreational boating demand in the Dunsborough region. In principal, a new facility could be either a new boat ramp (Level 4) or a harbour (Level 6). Numerous studies into a potential harbour in the Dunsborough region have been undertaken over the previous 30 years. A potential harbour on the sandy coastline would be subject to littoral drift and high associated maintenance costs. Given the current issues surrounding Port Geographe, public support for such a proposal is unlikely to be forthcoming in the near term and the financial viability is questionable. From an engineering perspective, a harbour on a rocky coastline has benefits. Previous such proposals, however, have been rejected by the Environmental Protection Authority (EPA) and large parts of the local community. The City of Busselton submitted a proposal under Regional Boating Facilities Scheme (RBFS) Round 16 for a planning study for a new Regional Boating Facility for the Dunsborough region. This study is to provide scientific and engineering data to allow a thorough assessment of potential sites and develop concept plans suitable for consultation. The need for this study is driven not only by the need for technical information to be provided to designers, but also because it is considered critical to demonstrate community support for a preferred site before detailed designs are developed. This grant application was approved by RBFS on 6 June After approved extensions, the approved date for completion of this project is 31 March The City of Busselton appointed Shore Coastal as project managers to facilitate the study. This summary report collates the technical studies and stakeholder engagement undertaken to achieve the requirements of the project. 3

6 City of Busselton Dunsbrough Region Boating Facility Planning Study 1.2 Demand for a new facility In the initial stages of the study, some basic demand analysis was undertaken to confirm the requirements for a new facility. In the Dunsborough region, the Department of Fisheries provided actual number of users for the Christmas period of During this two- week period, there were three (3) occasions where more than 150 boats were launched just from the Dunsborough, Quindalup and Abbey ramps, with 239 users on the peak day. This clearly exceeded trailer- parking capacity at the time of 111 bays, matching anecdotal evidence of widespread congestion and illegal parking of trailers. Even with the additional boat trailer parking recently constructed at the Quindalup (Sea Rescue) Boat Ramp, it is clear that additional recreational boating facilities are required to meet future demand around Dunsborough. Further demand analysis, evaluating the need in the overall City of Busselton, was undertaken by MP Rogers and Associates as part of their preliminary design analysis (MRA 2014, Report 5). This analysis used different methodology and different assumptions to the initial appraisal (e.g. different ratio of local users to tourists) and is included in the technical report. As with the earlier analysis, it was clear that the need for additional facilities is easily justified by the forecast demand for an additional 231 boat trailer parking bays by Figure 1.1 Quindalup Sea Rescue Ramp (Source Naturaliste Sea Rescue) 4

7 2 Initial Site Identification (9 Sites) City of Busselton 2.1 Planning Assessment A review of satellite imagery was undertaken with the City of Busselton to identify all potential sites for a future boat ramp and associated infrastructure in the Dunsborough region. Planning advice was sought from the City of Busselton Strategic Planners to identify planning issues surrounding each of the sites. Following this advice, a list of nine (9) potential sites was agreed upon (City of Busselton 2012 Report 1). These nine (9) potential sites were Canal Rocks (in National Park), Meelup/Eagle Bay, Caste Rock, Curtis Bay North and Curtis Bay South (in Meelup Regional Park), Quindalup Pro- fish, East Quindalup and Marybrook (on Crown Land) and Locke Estate or adjacent (Leasehold land or adjacent Crown Land to the west). The location of these sites is shown in Figure 2.1. The rapid assessment of these nine (9) sites by Strategic Planners from the City of Busselton indicated that each site had at least one significant challenge (Report 1 Planning Assessment). These nine (9) sites were taken to a Council briefing and a meeting of stakeholders for consideration and identification of a preferred site or sites. Figure 2.1 Initial Site Assessment (9 Sites) 5

8 2.2 Wave Modelling The wave climate at each of these nine (9) sites was evaluated in the wave modelling. It was recognised by the City that a new boating facility at open ocean sites within Geographe Bay might not meet the requirements of AS Guidelines for Design of Marinas under all conditions. Modelling the frequency of occurrence of conditions that meet AS3962 allowed the relative sheltering of sites to be compared and the risks to be quantified. Wave modelling was undertaken by Asia- Pacific Applied Science Associates (APASA 2013 Report 2). The percentage of times in summer that each of the nine (9) sites had waves less than 200mm is shown in Table 2.1. Table 2.1. Wave Modelling Summary (APASA 2012) LOCATION Percentage time in Summer waves less than 200mm RANKING QUINDALUP PRO FISH 66% 1 EAST QUINDALUP 56% 2 MARYBROOK 56% 3 LOCKE ESTATE 52% 4 CURTIS BAY SOUTH 51% 5 CURTIS BAY NORTH 39% 6 MEELUP/EAGLE BAY 39% 7 CASTLE BAY 29% 8 CANAL ROCKS 3% Hydrosurvey Initially, it was thought that the overall planning study would include conducting a Hydrosurvey adjacent to the Canal Rocks boat ramp. However, the 1996 survey by the Department of Transport (DOT ) was considered sufficient for the assessment of that site. Survey is currently being undertaken by the City of Busselton of the wider Geographe Bay that will allow better assessment of sediment transport rates at the Quindalup (Seas Rescue) and Locke estate sites in subsequent planning studies at the preferred sites. 2.4 Initial Stakeholder Consultation Carolyn Walker Public Relations was engaged as part of this project to develop and enact a community consultation strategy (CWPR 2012 Report 3). It was decided to use a stakeholder meeting to collaboratively review the issues surrounding each of the nine (9) potential sites in order to form a shortlist of three (3) to four (4) sites for further investigation. Stakeholders from a wide range of community groups attended this meeting, including representatives of boating, sea- rescue, environmental, business, indigenous and resident s groups, as well as DoT, local government officers, consultants and councillors. Using a Value Management 6

9 methodology, issues to consider at each site were grouped under Social, Environmental and Economic categories. Each site was given a rating for each issue by every stakeholder present. The results from these assessments were collated to give overall scores for each site. The whole group then discussed the overall scores and recommended three (3) sites for further investigation: 1) Quindalup Pro- fish. This is the site of an existing yacht club with a sand boat ramp and a mooring site for professional and commercial boats. 2) East Quindalup. This site would possibly require an access bridge across Toby Inlet. 3) Locke Estate or adjacent. This site is the furthest east, which is closer to both existing facilities at Abbey and the source of significant tourist traffic. The meeting noted that Canal Rocks could be considered if the unfavourable wave climate was able to be addressed. The development of a site at Canal Rocks with a breakwater (Option 4) was considered in further investigations and stakeholder engagement. 7

10 City of Busselton Dunsbrough Region Boating Facility Planning Study 3 Detailed Investigations (4 Sites) 3.1 Vegetation study A Level 1 Flora and Vegetation Survey of the three recommended sites, plus Canal Rocks, was commissioned from Onshore Environmental. The study found that there were no vegetation associations classified as Threatened Ecological Communities (TECs) on, or adjacent to, any of these four potential sites. There were, however, Priority Ecological Communities (PECs) in close proximity to each of the four (4) sites. Further detail on these vegetation associations is provided in the technical report (Onshore Environmental 2013 Report 4). The report found that it is unlikely that improvement and extension of the Canal Rocks Boat Ramp will have a significant impact on the adjacent PEC, particularly given the current condition of vegetation occurring adjacent to the existing ramp (page 23). The other sites, however, contain PEC Agonis flexuosa (peppermint) forests behind the foredune, and the report recommends that location of infrastructure and associated clearing is minimised within (this) community (page 23). Figure 3.1 Vegetation Mapping Quindalup (Pro Fish) (Onshore Environmental 2013) 3.2 Aboriginal Heritage Register The Aboriginal Heritage Inquiry System did not identify any Registered Aboriginal Sites or Other Heritage Places at any of these four (4) locations. 8

11 3.3 Coastal Process Analysis and Preliminary Design A preliminary design report was commissioned from MP Rogers and Associates, providing demand analysis for the proposed facility, coastal processes analysis and preliminary design for the three recommended sites, as well as concept design for a breakwater at Canal Rocks (MRA 2014 Report 5). The demand analysis demonstrated a clear need for additional recreational boating facilities, as has been discussed in Section 1.2. The Coastal Processes analysis identified significant risks of accretion and erosion (especially in storm events) and high volumes of sand and wrack bypassing at all three sites on the sandy Geographe Bay sites. Recommended Coastal Process Allowances and Design Considerations from the report are shown in Table 3.1. Table 3.1 Coastal Processes Assessment (MRA 2013) SITE ALLOWANCE FOR ACCRETION ALLOWANCE FOR EROSION* SEDIMENT TRANSPORT PAST SITE LOCKE ESTATE 25m 47m 10,000-30,000 m 3 /yr EAST QUINDALUP 30m 34m 10,000-30,000 m 3 /yr QUINDALUP 30m 42m 20,000-35,000 m 3 /yr PRO FISH *Preliminary designs incorporated seawall protection of facilities to reduce setback for erosion. The preliminary designs aimed to meet the requirements, as far as practical, of DoT s Guidelines for the Design of Boat Launching Facilities in Western Australia below the 24th Parallel (DoT, 2009). However the following was noted: The coastal process assessment of the three Geographe Bay sites determined the following. No site achieved the safe launching conditions required by AS3962 (2001) due to wave activity. The Canal Rocks ramp was the most exposed site and the Pro Fish site the most protected. During severe storms the three sites in Geographe Bay could experience erosion in the order of 30 to 50 m from the ephemeral dune vegetation. Development of the boat ramps would therefore require some seawall protection at each site. The Pro Fish and East Quindalup sites are generally accreting over the longer term while the Locke Estate site is estimated to be receding in the longer term. However, the shoreline position at these three sites has been observed to experience periods of rapid accretion. Therefore, the design of the boat ramps at 9

12 these sites needs to allow for accretions of about 25 to 30 m occurring from time to time. There have been a number of studies of the longshore transport of sand in Geographe Bay. These studies suggest that there is approximately 10,000 to 35,000 m 3 /yr net transport of sediment eastward past the sites. The sites could be affected by the accumulation of seagrass wrack and this would need to be managed. MRA Preliminary designs were prepared for the three (3) Geographe Bay sites for both conventional ramps and for elevated ramps. In order to obtain the toe depth specified under AS while making allowance for accretion, the preliminary designs specify boat ramps with reversing distances well over 50m. While this reversing distance is considered to be relatively long, it is understood similar length ramps are in use elsewhere in Western Australia (Port Kennedy). Estimates of the capital cost and maintenance cost for each of the concepts were undertaken by MRA The results of this comparison are shown in Table 3.2 (MRA 2014 Report 5). It should be noted that the capital cost for Canal Rocks is the only the breakwater cost and does not include allowance for repairs or upgrades to the boat ramp or expansion of the boat trailer parking. Table 3.2 Comparison of Sites and Concepts (MRA 2014) MRA 2014 concluded the following: The provision of breakwater protection at the Canal Rocks ramp is the only scheme that would provide a facility meeting the Australian Standards AS 3962 (2001) for wave conditions. The unprotected ramp concepts in Geographe Bay would be unsafe to use for a significant proportion of the time. On this basis, it is recommended that the provision of the breakwater protection at Canal Rocks be considered as the first priority for development. 10

13 It is also noted that there is significant demand for better facilities in Geographe Bay near Dunsborough. Consequently, it is recommended that the City confirm that developing unprotected ramps that don t meet the Australian Standards would not result in unacceptable risks due to public safety concerns. Should the City then wish to proceed with unprotected ramps, it is suggested that an elevated ramp at the Pro Fish site be given priority for the following reasons. The wave conditions at Pro Fish are the best of the three Geographe Bay sites. The sediment and seagrass wrack dynamics are less onerous than the Locke Estate site. Lower whole of life costs compared to a conventional ramp. The existing road access is suitable. The upgraded ramp facilities would complement the Dunsborough Bay Yacht Club. The site location is close to the Dunsborough population. (MRA 2014 Report 5) 3.4 Review and Council Briefing The MRA 2014 draft report has been reviewed by the Department of Transport and Department of Parks and Wildlife. These comments were incorporated into the final report however further consideration is required, in particular, to the size of any sheltered facility at Canal Rocks The findings of the technical studies (Reports 1 to 4) were presented to the City of Busselton Council at a Council Briefing in November Technical studies were subsequently completed and further stakeholder consultation undertaken on the four (4) nominated sites (Locke Estate, East Quindalup, Quindalup (Sea Rescue) and Canal Rocks. The results of these studies and consultation will be submitted to Council for consideration. 3.5 Further Stakeholder Consultation Further consultation with stakeholders on four (4) sites was held on February 26, 2014 (Carolyn Walker 2014 Report 6). This meeting followed a similar format to the previous stakeholder meeting, using a Value Management methodology. The following four concepts were assessed: Quindalup Pro Fish: A two lane elevated ramp with associated finger jetty and parking at Quindalup Pro- Fish. East Quindalup: A two lane elevated ramp with associated finger jetty and parking at East Quindalup, without the construction of a bridge over Toby Inlet Locke Estate: A two lane elevated ramp with associated finger jetty and parking on land immediately west of Locke Estate. Canal Rocks: Upgrade of the existing two- lane facility at Canal Rocks, including construction of a breakwater. 11

14 Following review of this process, workshop participants generally agreed: Canal Rocks and Locke Estate are supported on a simple score basis within the assumptions made, with some concern expressed for open ocean safety. Technically Quindalup Pro is the most suited (for approvals) and safest option (in Geographe Bay) as a coastal engineering design. If it resulted then: o o Need consideration for yacht access as a regional yachting destination. A rationalisation of moorings may be needed to avoid conflict in peak demand by DPaW with a supporting Mooring Plan. Technically Canal Rocks with a breakwater is the only way that the Australian Standard for wave height at the boat ramp can be met. The risks associated with breakwater access and egress needs to be understood and quantified if a Canal rocks solution resulted. Quindalup East could be an option only if a bridge were constructed from Geographe Bay Road. A better understanding of the needs and origins/destinations of boat owners is needed to ensure the resultant facility is optimally located to satisfy future demand. If a Geographe Bay option resulted then more possum research would be required. 12

15 4 Recommendations 4.1 Study Outcomes Each site has challenges that need further investigation prior to commitment to construct a facility at that location. However, preferred sites have been identified and key issues at each site clarified. The major challenges at each site are summarised as follows: A) Quindalup Pro- fish. a. Marine Precinct Plan. This would require preparation of plan for the way the interaction of the diverse boat users could safely operate in this area. Users include the yacht club, professional fishermen, commercial tour operators and recreational boaters. b. Vegetation and fauna. A Level 2 vegetation study and a possum survey should be undertaken. This could lead to:- B) Adjacent to Locke Estate i. modification of the design of the land- based facilities; ii. preparation of an offset plan for replacement of possum habitat; and iii. potential referral to the federal Department of Environment for evaluation. a. Demand in this location. The Locke Estate site is the furthest from Cape Naturaliste and the west coast, which anecdotally is the destination for the majority of recreational boat users. It is therefore recommended that a survey be undertaken of at existing boat ramps in the Dunsborough region during the peak summer period. Such a survey would include:- i. Place of registration of boat; ii. Place boat was housed the previous night; iii. Intended destination; and iv. Reason this boat ramp was chosen. Such a survey would assist understanding of boating demand in the Dunsborough region and help determine whether an additional facility adjacent to Locke Estate would meet that demand. b. Vegetation and fauna. Similar to the Pro- Fish site, although as the site adjacent to Locke Estate site is heavily vegetated, this is likely to be an even more significant issue at this location. 13

16 C) Canal Rocks a. Effect of sea- state conditions. The design of the breakwater should be further evaluated and refined to evaluate the effect of: i. surges in the water level due to long period waves ii. potential risks entering and leaving the shelter of the breakwaters during heavy swell and high wave conditions. Discussions should also be held with DoT regarding the breakwater design. b. Location in National Park. This study has been undertaken for the City of Busselton. This facility, however, is located within the Leeuwin- Naturaliste National Park and is managed by the Department of Parks and Wildlife. Further planning for a facility on this site would require increased involvement of Department of Parks and Wildlife (DPaW) and Department of Transport (DoT). Public consultation should be held for all concepts in addition to the technical considerations specific to each site. 4.2 Way Forward There are a number of recommendations from the individual technical reports that require further consideration going forward. These recommendations are outlined in the individual reports. It particular, the outcomes of the recent stakeholder engagement provide a broad framework going forward. Whilst a technical preferred site has been identified, broader community acceptance of any proposal will be required. On the basis of the technical studies and stakeholder engagement undertaken for this project, we would recommend the following way forward: 1. Council considers the outcomes of the February 2014 stakeholder engagement workshop. 2. Wider public consultation is undertaken on the preliminary designs for Canal Rocks, Quindalup (Pro Fish) and Locke Estate. 3. Further investigations are undertaken by the City of Busselton to nominate a preferred site for Geographe Bay. These should be focused on the community preferred (Locke Estate) and the technically preferred (Quindalup Pro Fish) sites. These investigations should include, as a minimum, a Level 2 flora and fauna survey, a boat user survey during a peak period and development of a marine precinct plan to manage boat user conflicts at the Pro Fish ramp. 4. Further consideration is given to the risks of open ocean ramps within Geographe Bay. 5. Further consultation between City of Busselton, Department of Parks and Wildlife and Department of Transport with regards to the Canal Rocks proposal. 6. Nomination of either a preferred Geographe Bay site, or the Canal Rocks site, for further development of approvals and design. These recommendations should be the basis for the next phase of this project. A funding application has been submitted to the round 19 RBFS and would commence in the 2014/15 financial year subject to a successful grant application. 14

17 5 Glossary Source: USACE 2003 Glossary of Coastal Terminology, EM Accretion Artificial Nourishment Beach Berm Beach Erosion Breakwater Chart Datum Coastal Processes Cusp Crest Downdrift Erosion Groyne Littoral Drift May be either natural or artificial. Natural accretion is the buildup of land, solely by the action of the forces of nature, on a beach by deposition of water- or airborne material. Artificial accretion is a similar buildup of land by reason of an act of man, such as the accretion formed by a GROYNE, BREAKWATER, or beach fill deposited by mechanical means. The process of replenishing a beach with material (usually sand) obtained from another location. A nearly horizontal part of the beach or backshore formed by the deposit of material by wave action. Some beaches have no berms, others have one or several. The carrying away of beach materials by wave action, tidal currents, littoral currents, or wind. A man- made structure protecting a shore area, harbor, anchorage, or basin from waves. A harbor work. The plane or level to which soundings (or elevations) or tide heights are referenced (usually LOW WATER DATUM). The surface is called a tidal datum when referred to a certain phase of tide. To provide a safety factor for navigation, some level lower than MEAN SEA LEVEL is generally selected for hydrographic charts, such as MEAN LOW WATER or MEAN LOWER LOW WATER. Collective term covering the action of natural forces on the SHORELINE, and near shore seabed One of a series of short ridges on the FORESHORE separated by crescent- shaped troughs spaced at more or less regular intervals. Between these cusps are hollows. The cusps are spaced at somewhat uniform distances along beaches. They represent a combination of constructive and destructive processes. CREST Highest point on a beach face, BREAKWATER, or SEAWALL. The direction of predominant movement of littoral materials. The wearing away of land by the action of natural forces. On a beach, the carrying away of beach material by wave action, tidal currents, littoral currents, or by deflation. Narrow, roughly shore- normal structure built to reduce longshore currents, and/or to trap and retain littoral material. Most groins are of timber or rock and extend from a SEAWALL, or the backshore, well onto the foreshore and rarely even further offshore The movement of beach material in the littoral zone by waves and currents. Includes movement parallel (long shore drift) and sometimes also 15

18 perpendicular (cross- shore transport) to the shore. Nourishment Overtopping Recession Runup Salient Sand Scarp, Beach Scour Scour Protection Seawall Still Water level Storm Surge Updrift The process of replenishing a beach. It may occur naturally by longshore transport, or be brought about artificially by the deposition of dredged materials or of materials trucked in from upland sites. Passing of water over the top of a structure as a result of wave runup or surge action. A continuing landward movement of the shoreline. (2) A net landward movement of the shoreline over a specified time. The upper level reached by a wave on a beach or coastal structure, relative to still- water level. A bulge in the coastline projecting towards an offshore island or breakwater, but not connected to it as in the case of a TOMBOLO - see also Ness and Cusp. Developed by WAVE REFRACTION and diffraction and long shore drift. Sediment particles, often largely composed of quartz, with a diameter of between mm and 2 mm, generally classified as fine, medium, coarse or very coarse. Beach sand may sometimes be composed of organic sediments such as calcareous reef debris or shell fragments. An almost vertical slope along the beach caused by erosion by wave action. It may vary in height from a few cm to a meter or so, depending on wave action and the nature and composition of the beach. (See Figure A- 1) See also ESCARPMENT. Removal of underwater material by waves and currents, especially at the base or toe of a shore structure. Protection against erosion of the seabed in front of the toe. 1) A structure, often concrete or stone, built along a portion of a coast to prevent erosion and other damage by wave action. Often it retains earth against its shoreward face. (2) A structure separating land and water areas to alleviate the risk of flooding by the sea. Generally shore- parallel, although some reclamation SEAWALLS may include lengths that are normal or oblique to the (original) shoreline. A SEAWALL is typically more massive and capable of resisting greater wave forces than a BULKHEAD. The surface of the water if all wave and wind action were to cease. In deep water this level approximates the midpoint of the wave height. In shallow water it is nearer to the trough than the crest. Also called the UNDISTURBED WATER LEVEL. A rise above normal water level on the open coast due to the action of wind stress on the water surface. Storm surge resulting from a hurricane also includes that rise in level due to atmospheric pressure reduction as well as that due to wind stress. The direction opposite that of the predominant movement of littoral materials. 16

19 6 References Asia Pacific ASA 2012, City of Busselton Dunsborough Region: Wave Modelling Study, report no. J0173 (Report 1). City of Busselton 2012, Dunsborough Regional Boat Ramp Planning Study CoB Strategic Planning Dunsborough Coastal Boating Environmental and Planning Framework assessment (Report 2). Carolyn Walker Public Relations 2012, Dunsborough Region Boating Facility Planning Study, Stakeholder Reference Group, Value Management Workshop (Report 3). Carolyn Walker Public Relations 2014, Dunsborough Region Boating Facility Planning Study, Stakeholder Reference Group, Value Management Workshop #2, 26 th February 2014 (Report 6). MP Rogers & Associates 2014, Dunsborough Regional Boating Facility Planning Study: Preliminary Design at 4 Sites report no. R384 Rev 1 (Report 5). Onshore Environmental 2013, Dunsborough Regional Boating Facility Planning Study: Level 1 Flora and Vegetation Survey (Report 4). Shore Coastal 2011 Capes Region Boating Strategy. SCR1005 Rev C January