NSW Maritime Panel and PIANC Australia

Practical Adaption to Climate Change on NSW Coasts

Port and Harbour Considerations

Greg Britton, WorleyParsons

Monday 24th August 2009

9/09/2009

Focus of talk

� Adaptation, not mitigation� Not considering issues

such as carbon footprints and trading, sustainability of material inputs, energy use, etc

� Ports are considering these issues, eg Sydney Ports Green Port Guidelines

9/09/2009

Why are ports and harbours vulnerable to climate change?

� potential effects of climate change• sea level rise• increased rainfall intensity /

frequency• changes to ocean storm

intensity (increased wave heights)

• increased wind loads• ocean currents• acidification

� features of ports and harbours

Source: DECC (2009)Draft Technical Note: Scientific basis of the 2009 sea level rise

benchmark

Features of ports and harbours:

� location: connected to the sea (sea level rise)

• embayments : natural, man-made (relative protection)

• in the open sea (storminess)

• within river estuaries (rainfall / runoff, sedimentation)

Features of ports and harbours:

� channels, berthing basins, swinging basins• declared depth• water surface level variation• bed level variation

� land / water interface infrastructure: wharves, jetties, dolphins• functionality, eg deck level• uptime• susceptibility for damage• associated equipment, eg

shiploaders

Features of ports and harbours:

� protective structures; breakwaters, seawalls, revetments• depth limited waves, stability• overtopping performance• degree of exposure

� land-based infrastructure: hardstand, stockpile areas, buildings, roads, stormwater• flooding• drainage• water quality

Features of ports and harbours:

� planning life

• infrastructure

• equipment

� significance to the Australian economy

• ports act as the gateway for trade into and out of Australia andobviously have vast economic significance

• 83% of all our exports by value (about $100 billion)

• 70% of all our imports by value (about $80 billion)

Factors affecting climate change adaption methodologies for ports and harbours:

� uncertainty in the magnitude of climate change effects

� high natural variability in existing physical processes

� significant embedded infrastructure

� life of infrastructure, including variability of components

� infrastructure must be functional now as well as over its future life

Ultimately a flexible approach required, risk based assessment, often a low investment outcome adopted

Existing Guidelines:

� AS 4997-2005 Guidelines for Design of Maritime Structures. Focus on sea level rise.• amount of SLR depends on design life• does not necessarily mean raised decks• examples of allowance for SLR: raise heights of restraining

piles on floating structures at a later time, or install substructure of adequate strength to permit future topping slabs etc.

� Guidelines for Responding to the Effects of Climate Change in Coastal and Ocean Engineering (Engineers Australia, 2004 Update): retreat, accommodate or protect.

� International practice

Some examples of adaptive methodologies:

� Port of Newcastle maintenance dredging of shipping channels

� Sydney Harbour Ferry Wharves Upgrade

Port of Newcastle maintenance dredging:

� located on a major river estuary subject to flooding (Hunter River)

� ongoing requirement for maintenance dredging, commenced 1859, greater than 130 Mm3 to date, typically 200,000 to 300,000 m3 per annum

� two sources of sedimentation

• fluvial inputs

• coastal processes

Adaptive approach:

� retain NPC owned dredger

� seek permit for high range maintenance dredging quantity

� seek alternative disposal areas

� undertake regular hydrographic surveys including surveys beyond channel limits

� supplement NPC dredger with contract dredger as required

Sydney Harbour Ferry Wharves Upgrade:

� NSW Maritime has upgrade strategy for 46 ferry wharves over next 15 years

� WorleyParsons has undertaken review of standard concept wharf designs, addressing following issues:

• general design criteria, eg design life, sea level rise

• site specific environmental design criteria

• operational constraints, including disabled access

• value engineering review, including public safety

Sydney Harbour Ferry Wharves Upgrade:

Important design details

� design life 50 years

� fixed landing level

� hinged access ramp slope, length, width

� satisfying disability guidelines for accessible public transport

Adaptive approach

� fixed landing level 2.9m CD, longer ramps

Conclusion:

� ports are vital to the economy

� restricted attention has been given to date to impacts of climate change on port infrastructure, port operations and the environment

� attention is likely to have to escalate