Hydrographic Authority PACIFIC REGIONAL NAVIGATION INITIATIVE SAMOA Hydrographic Risk Assessment Annexes Report Number: RNALZ17001_C Version: 1.1 Date: 17 September 2017 SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________ Supported by the New Zealand Aid Programme PACIFIC REGIONAL NAVIGATION INITIATIVE SAMOA Hydrographic Risk Assessment Annexes A joint production by: Land Information New Zealand Level 7 Radio New Zealand House 155 The Terrace Wellington NEW ZEALAND and Rod Nairn & Associates Pty Ltd Hydrographic and Maritime Consultants ABN 50 163 730 58 42 Tamarind Drive Cordeaux Heights NSW AUSTRALIA Authors: Rod Nairn, Michael Beard, Stuart Caie, Ian Harrison, James O’Brien Disclaimer: The views expressed in this publication do not necessarily reflect those of the New Zealand Government. Satellite AIS data under licence from ORBCOM (augmented by IHS Global Pte Ltd) ii Rod Nairn and Associates Pty Ltd Hydrographic and Maritime Consultants SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________ SAMOA Hydrographic Risk Assessment Annexes A. Event Trees B. GIS Track Creation and Processing C. Traffic Risk Calculation D. Likelihood and Consequence Factors E. Hydrographic Risk Factor Weighting Matrices F. Hydrographic Risk Calculations G. Benefits of Hydrographic Surveys to SAMOA H. List of Consultations References RNA 20170916_C_V1.1 iii SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________ This page intentionally blank RNA 20170916_C_V1.1 iv SAMOA Hydrographic Risk Assessment _______________________________________________________________________________________ ANNEX A - Event Trees 1. Event trees were used to determine the most likely and worst credible impacts of defined unwanted navigation events. For consistency and commonality across the South West Pacific hydrographic risk assessment area, the event trees in this Annex are based on the generic event trees in the Risk Assessment Methodology1 and those used in the Cook Islands2 and Tonga3 and Niue4. 2. Samoa has substantial domestic traffic due to the frequent inter-island passenger/vehicle ferry service from Mulifanua to Salelologa and regular cargo/fuel journeys from Apia to Salelologa. This category represents the highest likelihood of incident due to the frequency of passages and the constrained navigation at the terminal ports. 3. Recreational vessels present a different type of risk in that this class of vessel is more likely to navigate into poorly charted waters in remote areas and therefore do present a risk, though consequence is limited to personnel casualties. Accordingly, an event tree that covers the grounding of recreational vessels has been included. 3. The event trees were used to confirm the veracity of the weightings of the risk consequence factors employed in the overall risk calculations and to estimate consequential costs of incidents in the cost benefit analysis (described in Section 8 of the main report). 1 (Marico Marine Report No. 15NZ322 Issue 03, 5 August 2015) 2 (Marico Marine Report No. 14NZ262MR Issue 02, 20 January 2015) 3 (Marico Marine Report No. 14NZ262 – TM, Issue 1, 27 November 2014) 4 (RNAPL16002 - NIUE Hydrographic Risk Assessment, 2016, p. Annex A) RNA 20170916_C_V1.1 Page A-1 SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________________________________________________________________________________________________________________________________ ANNEX A - Event Trees Marine Accident Grounding Foundering Collision Recreational Vessel SOLAS Dry Cargo SOLAS Liquid Bulk SOLAS Passenger Most Likely Scenario Worst Credible Scenario Vessel grounds at night or in bad weather on Vessel breaks mooring weather side of island and is washed ashore on and breaks up to reef. Most likely Worst Credible consequence impacts consequence impacts Environment Property Economic/Stakeholder Stakeholder/Economic People Possible loss of 100 Vessel suffers some Search and rescue Environment People litres diesel fuel. hull and propellor Property efforts by Samoa. Cost of repairs by Minor physical damage. Can be Minor disruption to Minor physical boatowner. damage to reef, refloated and Possibly 2 fatalities Vessel a total loss. fishing. Diesel spill damage to reef in debris field along repaired at Apia with Minor local disruption and serious injury insignificant but Nil or minor injuries vicinity of grounding. coast minor impact local and shipped to tourists and temporary disruption to on fishing and equipment Possible spillage of subsistence fishing. tourism 100 litres diesel. foreshore. RNA 20170916_C_V1.1 A-2 SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________________________________________________________________________________________________________________________________ ANNEX A - Event Trees Marine Accident Grounding Foundering Collision Recreational Vessel SOLAS Dry Cargo SOLAS Liquid Bulk SOLAS Passenger Worst Credible Scenario Most Likely Scenario Vessel grounds at high Vessel grounds at low speed on fringing reef due speed while cyclone, poor manoeuvring entering weather/visibility, Apia, through navigation equipment or equipment failure, engine failure. Salvage tug human error. and international cleanup effort required Most likely Worst Credible consequence impacts consequence impacts People Economic/Stakeholder Stakeholder/Economic Property Environment People Environment Property Loss of national tourism Possible loss of 300 income, damage to Vessel suffers minor Possible release of 1 Possible failure of tonnes MFO bunkers. local reef and fish damage on coastal Serious hull and tonne MFO. Minor planned cargo Possibility of injuries stocks and breeding reef. Vessel able to structural damage, Massive damage to physical damage to exchange will have or fatalities areas. Interruption to clear reef under own requires salvage and reef, breeding reef ivo grounding. minimal impact. particularly if ship subsistence fishing. power. drydocking or may be grounds, and tourist No injuries Local pollution Schedule of island re- strands and is provisioning disrupted a total loss. sites. International media impact on abandoned interest. subsistence fishing Some impact on and tourist sites. tourism. RNA 20170916_C_V1.1 A-3 SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________________________________________________________________________________________________________________________________ ANNEX A - Event Trees Marine Accident Grounding Foundering Collision Recreational Vessel SOLAS Dry Cargo SOLAS Liquid Bulk SOLAS Passenger Most Likely Scenario Worst Credible Scenario Cyclone avoidance - vessel navigates to sea Vessel encounters to avoid and remain cyclone and is unable to clear of dangerous navigate to safety, cargo semicircle. shifts and vessel becomes unstable - lists Experiences heavy and sinks. weather Most likely Worst Credible consequence impacts consequence impacts Economic/Stakeholder Environment Stakeholder/Economic Disruption to Property Environment Vessel sinks in deep People People import/export cycle, Property water. All fuel leaks loss of cargo created Vessel suffers storm Cargo lost overboard Schedule delay in cargo to sea slowly and Possibility of crew may present danger Possibility of entire temporary difficulty. damage, possible loss exchange may impact Total loss of vessel dissipates. Oil slick injury with shifting to navigation and Samoa. crew being lost (20 on exposed shores to Loss of national tourism cargo of containers or and cargo damage to cargo. may wash up ashore persons) leeward. Deck cargo income as pollution on exposed coasts. Some cargo may be impact on tourist sites. lost or damaged. breaks free and some buoyant items cause International press navigation hazard or interest wash ashore RNA 20170916_C_V1.1 A-4 SAMOA Hydrographic Risk Assessment _________________________________________________________________________________________________________________________________________________________________________________________________________________ ANNEX A - Event Trees Marine Accident Grounding Foundering Collision Recreational Vessel SOLAS Dry Cargo SOLAS Liquid Bulk SOLAS Passenger Worst Credible Scenario Most Likely Scenario T-bone collision. Glancing collisiion in Extensive damage to open sea, with plate both vessels above and indentation and some below waterline but splitting above the neither vessel sinks. waterline requiring in Cargo tank ruptured and water repairs possibility of fire/explosion. Most likely Worst Credible consequence impacts consequence impacts Environment Economic/Stakeholder Property Environment Property People Stakeholder/Economic People Possible loss of 300 Loss of national tourism tonnes HFO. Oil slick income, damage to could impact on Vessel suffers Nil impact to Samoa local reef and fish Samoan coast. Long damage requiring stocks and breeding Both vessels require term damage to repairs alongside - areas. Interruption to Serious injuries and 1 repair in dry dock. biological sensitive slow transit to port Some international subsistence fishing. Minor injuries media interest fatality One vessel requires areas and fish of repair tow to repair port International media