Motivation

1. Environmental Design of Cottesloe Rock Swimming PoolFinal Year Project PresentationDate: 16th October 2013Luan Nguyen Presenter, School of Civil and Resource Engineering, the University of Western AustraliaJorg Imberger & Clelia MartiSupervisors, Centre for Water Research

2. Motivation Purpose of Research • Design of the environmental parameters of a low maintenance/maintenance-free rock swimming pool, constructed as an extension of the existing groyne. • Conduct structural design and feasibility study of the placement of the structure (to be done by Dan Courtney). • A facility for public usage as a mean for safe swimming, disability access and recreational activities. • To reflect the rich culture of Cottesloe and the history of the beach.

3. Study Domain Area of Research 500 m 500 m 500 m SOURCE: Google Maps & Google Earth

4. Current Proposal Conceptual Design for the current proposal 75m 25m AFTER BEFORE SOURCE: nearmap.com

5. Objective Goals of Research Determine environmental and cultural impacts of the placement of the Cottesloe Rock Swimming Pool by delivering environmental parameters of the system as inputs for structural design and public engagement techniques.

6. Approach Research Methodology

7. Wave Model - SWAN Wave breaking, bottom friction, reflection, diffraction, refraction and triad Description of model Validation: Cottesloe Wave Station Outputs: Significant wave height, period and direction Cottesloe Domain Cottesloe Domain SWAN Wind Field Weather Forecast and Research Model (WRF) Wind Field Perth Coastal Margin SWAN Nesting Spectrum Field Data from Carnac Wave Logger SOURCE: Google Earth

8. Wave Model - SWAN Control Case Modified Case • Pool’s wall added • Submerged reef near tip of groyne to ensure high waves near tip of groyne • Grid size: 5 x 5 m uniform grid • Quadruplets turned off due to shallow water • Model groyne as obstacle • Size: 550 x 1010 SOURCE: ARMS

9. Hydrodynamics Model - ELCOM Control Case Modified Case Pool’s wall added Submerged reef near tip of groyne to ensure high waves near tip of groyne • Plaid grid size with 50 m coarse grid and 5m fine grid • Wave forcing from CWR’s Perth Coastal Margin Model • Wind data from CWR’s Lake Diagnostic System • Default coefficients as given in user manual • Size: 500 x 1000 SOURCE: ARMS

10. ELCOM Tracers 4 4 3 3 2 2 1 1 5 5 6 6 SOURCE: ARMS & Google Earth

11. CWR’s Cottesloe Wave Logger Description of Validation Tool • Installed at the corner of SWAN’s domain • Record 15-minute intervals of wave height, period and direction • Use as a validationtool for the model

12. CWR’s Cottesloe Wave Logger Example of Outputs

13. RESULTS AND DISCUSSION

14. SWAN Results Discussion of SWAN Outputs – Significant Wave Height Control Case Modified Case SOURCE: ARMS

15. SWAN Results Comparison of the two cases SOURCE: ARMS

16. SWAN Results Higher waves within submerged reef region Comparison of the two cases SOURCE: ARMS

17. SWAN Results Higher waves within submerged reef region Comparison of the two cases Higher waves near pool wall SOURCE: ARMS

18. SWAN Results Similar wave conditions nearshore Comparison of the two cases SOURCE: ARMS

19. SWAN Results Wave near pool edge SOURCE: ARMS

20. SWAN Results Phase Differences between High and Low Water 1 2 Graph generated by Matlab

21. SWAN Results Data Validation SOURCE: ARMS

22. SWAN Results Discussion of SWAN Outputs – Mean Wave Period Control Case Modified Case SOURCE: ARMS

23. ELCOM Results Example of Tracer Outputs

24. ELCOM Results Example of Speed Outputs SOURCE: ARMS

25. Conclusion • Higher waves are experienced near the tip of the groyne and submerged reef area due to depth-induced breaking • Higher waves near tip of groyne and lower wave near side of pool can encourage flushing cycle of the water inside the structure • ELCOM results suggested there are changes in current velocity near the bed which can result in changing in shoreline

26. Recommendations • Continue SWAN realtime simulation for at least 6 months to gain enough data for 75-100 years design period • Determine sedimentary transport rate using Shield’s parameter and current outputs from ELCOM • Preliminary geometric design can still be performed using available logger and model data

27. SWAN Wave Model Details of Realtime Model • Visit CWR’s Realtime Management System Online (RMSO) • Select to view Simulations • Select to view the Perth Coastal Margin • Select GROYNE for control case, POOL for modified case • Select wave parameter to be viewed www.rmso.com.au

28. SWAN Wave Model Details of Realtime Model Model located under Simulations Model runs as nested domain in PCM Select COT-GROYNE for Control Case, COT-POOL for modified case Select variable to be viewed

29. Public Engagement Description of Website • Use as a tool for public engagement • To be used to educate, communicate to the main user groups in WA and as a space for the community to contribute inputs to the project • Still in development stage www.cwr.uwa.edu.au/cottrock/

30. Public Engagement Description of Website

31. Acknowledgement I would like to say thanks to: • My supervisors Jorg and Clelia • Jorg’s personal assistants: Emilia and Laura T • Project initiator: Tom Locke • CWR’s staffs and field team • Special thanks to Lee and Leticia for modelling help • PhD students for providing technical assistance: Daniel, Christina, Mahmood, Bronwyn, Vahid • Fellow intern students: Linh, Laura B, Lee, Josh, Saba, Dan, Taylor, Melanie, Laurianne, Gwendelyn, Geraldine • My friends and family • My workplace • Project supporters including Professor Bloomfield

32. Questions?

33. CWR’s Cottesloe Wave Logger Description of Wave Logger

34. CWR’s Cottesloe Wave Logger Description of Wave Logger