Climate Change and Sea level Rise: Challenges for Manilas - PowerPoint PPT Presentation

Climate Change and Sea level Rise: Challenges for Manila’s Infrastructure David van Senden APAC Water Resources Director

Presentation Overview • Climate Change and Sea Level Rise • Laguna de Bay – Water Source • Coastal Processes and Planning Examples - NSW • Concluding remarks

Future Climate Effects • Gradual sea level rise ( rising hinterland water tables and increased flooding ) • Increased storm intensity with fewer storms but larger wave events (coastal erosion) • Dryer but more intense rainfall events (extreme event flooding) • River meets Sea - Joint probability ocean storm surge with waves and catchment flooding needed to assess risk, emergency management challenge • Infrastructure Design life – how to accommodate future changes

Projected 30% reduction in Rainfall in Laguna • Catchment by 2060 0.4 m sea level rise by 2060 (Flooding and • Saline ingress to Lake) Competing water demands and changing quality LLDA Website

Hydrodynamic investigation of a shallow tropical lake environment (Laguna Lake, Philippines) and associated implications for eutrophic vulnerability, Herrera et al. (2015)

LLDA Website

Laguna de Bay Water Source risks over next 50 years? Rising Sea Level – increased tidal flushing and salt ingress Tidal barrage, flood mitigation works Reduced rainfall – decreased flushing and water quality West Bay development – increased contamination and poor water quality dispersing eastwards Changing treatment requirements during life time of WTPs

Coastal Storm Erosion Collaroy/ Narrabeen June 2016 Storm Erosion Planning: 2 decades inaction 2005 Buyback Value ~$800M Today’s value? Proposal for Funding Protection works 10 % State/Local Gov. 90% Residents contribution

Coastal Hazard Planning

Concluding Remarks Long term adjustments of natural systems due to Climate Change and Sea Level Rise need to be incorporated into Infrastructure Design projects • Adjustments due to CC and SLR required during the Infrastructure life cycle • Economic Assessments cost implications to ensure true viability assessment • Community engagement – LG Educate about CC and SLR implications • Improved Modelling – Long term predictions Joint occurrence events (forecasts for emergency management), • Monitoring – for long term trends and are IPCC/others projections being realized? • Better conversion of Data to Information • Ongoing Risk Review and Adaptive Management

Thank you