Drainage and Nature-Based Solutions (NbS) Expert

Drainage and Nature-Based Solutions (NbS) Expert

Project Type

Construction Supervision for the Civil Works of Bridge and it’s Approach Roads

Introduction of the Project

The project will construct a 720-meter, two-lane bridge across the Fanga’uta Lagoon, together with 2.1 km of approach roads, linking Nuku’alofa to southern Tongatapu. The bridge will strengthen Tonga's key economic corridor by providing an alternative, resilient connection between Fua‘amotu International Airport and the Queen Salote International Wharf.

Project Output

[Project Output 1] Transport connectivity between Nuku’alofa and southern Tongatapu strengthened

: The program aims to strengthen governance and institutional capacity in Tonga’s urban, water, and road sectors for long-term climate resilience and sustainable asset management. It will enhance MOI’s capacity to manage resilient infrastructure, develop social inclusion and evacuation plans, and guide climate-resilient urban and water planning through a Sustainable Spatial Planning Framework. Community resilience will be reinforced with inclusive disaster risk management and digital early warning systems.

 

[Project Output 2] Transport connectivity between Nuku’alofa and southern Tongatapu strengthened

: The project will build a 720-meter, two-lane bridge with 2.1 km of approach roads across the Fanga’uta Lagoon, creating a resilient link between Tonga’s main airport and wharf. Climate and disaster risks will be integrated into the design through flood protection, cyclone resilience, elevated roads with drainage, and durable construction features. A gender-responsive road safety education program will also be implemented to ensure safe and inclusive use of the new infrastructure.

 

[Project Output 3] Climate-resilient and nature-based urban water infrastructure enhanced

: The project will apply climate-informed “sponge city” and other nature-based solutions in Nuku’alofa to address flooding and water insecurity from intensified rainfall and storm surges. Activities include building 7.3 km of urban drains, installing retention ponds and infiltration systems, restoring nature-based stormwater networks, and rehabilitating water supply systems to cut non-revenue water below 20% with advanced monitoring. These measures will enhance water security, improve operational efficiency, reduce climate vulnerability, and promote gender equality by increasing women’s participation in technical roles.

Summary of Scope of Work

(i) Contract supervision & quality assurance: Oversee construction, approve methods/materials, monitor safety, test compliance, and certify payments.

(ii) Safeguards & inclusion: Ensure implementation of CESMP, LAP, GAP, SEP, and GRM; support gender and social inclusion, training, and awareness programs.

(iii) Project monitoring & reporting: Develop and manage the PPMS; prepare monthly/quarterly/annual reports; handle contractor claims, variations, and progress tracking.

(iv) Capacity building & stakeholder engagement: Support MOI, PMU, and contractors with training, consultations, and implementation of safeguard plans.

(v) Handover & completion: Lead bridge O&M manual finalization, prepare an emergency evacuation plan, and assist MOI with the Project Completion Report.

 

I. Contract management, administration, and supervision

(i) Contract & project management: Oversee contracts, budgets, schedules, payments, handover, and maintain strong relationships with contractors, MOI, and stakeholders.

(ii) Quality management: Develop and implement a quality management system for design, construction, testing, and commissioning; monitor compliance and address non-conformances with training or corrective actions.

(iii) Safety oversight: Conduct safety audits at pre-, during, and post-construction stages, and ensure works meet international safety standards.

(iv) Capacity building & documentation: Update project manuals, support audits, and provide on-the-job training to MOI staff.

 

II. Environmental safeguards

(i) Implementation & compliance: Ensure all environmental safeguards, including Codes of Environmental Practice, are applied and comply with national laws and ADB requirements.

(ii) ESMS & CESMP management: Establish and manage the Environmental and Social Management System (ESMS); review, support, and approve contractor CESMPs.

(iii) Training & guidance: Provide environmental training and guidance to MOI, PMU staff, and contractors.

(iv) Monitoring & reporting: Inspect and monitor compliance, document incidents, issue corrective actions, and contribute to quarterly and semi-annual safeguard reports.

(v) Stakeholder engagement & regulatory support: Coordinate SEP and GRM implementation, and assist contractors with permits, licenses, and regulatory approvals.

 

III. Social safeguards and gender

(i) Land Acquisition & Compensation: Support implementation of the LAP, ensure completion of compensation, manage GRM, and submit validation and compensation reports for ADB clearance.

(ii) Social Safeguards Monitoring: Supervise contractor compliance with social safeguards, address non-compliance, and manage unanticipated land acquisition or access impacts.

(iii) Stakeholder Engagement: Implement SEP, conduct gender-inclusive consultations with affected persons and communities, and document all engagement.

(iv) Gender Action Plan (GAP) & GEDSI: Implement GAP targets, support MOI capacity building, develop GEDSI Action Plan, integrate gender and inclusion into urban, water, and WASH planning.

(v) Community & Safety Programs: Support community-based disaster risk management, implement Gender-Responsive Road Safety Program, and conduct SEAH and communicable disease training for contractors.

(vi) Reporting & Monitoring: Contribute to quarterly and semi-annual safeguards, GAP, and gender reports for ADB; monitor progress on safeguards, gender, and social inclusion indicators.

 

IV. Operations and maintenance manual

(i) Review the existing Bridge O&M Manual for technical accuracy, clarity, and local applicability.

(ii) Identify gaps, inconsistencies, or areas needing simplification or elaboration.

(iii) Consult with stakeholders (MOI, local authorities, maintenance contractors) to ensure practicality and ownership.

(iv) Revise the manual to include roles/responsibilities, routine and periodic maintenance, emergency protocols, inspection schedules, and resource needs.

(v) Provide a summary briefing and presentation to stakeholders on the revised manual.

 

V. Evacuation Plan

(i) Situational Analysis & Risk Assessment: Review existing emergency frameworks, identify hazard-prone areas, map vulnerable populations, and assess bridge usage during emergencies.

(ii) Traffic Management Planning: Develop evacuation-specific traffic plans, identify primary/secondary routes, staging areas, traffic control points, and assess transport capacity needs for persons with limited mobility.

(iii) Stakeholder Coordination & Community Engagement: Work with ministries, NGOs, community groups, and DPOs; facilitate workshops and consultations to ensure local input and ownership.

(iv) Inclusive Evacuation Plan Development: Integrate gender-responsive methods, disability- and child/youth-friendly measures, accessible communication materials, and recommend early warning improvements.

(v) Finalization: Prepare the final evacuation plan incorporating stakeholder feedback.

 Main Responsibilities

The expert will support the Team Leader in the design review, administration, and supervision of drainage and NBS components, ensuring that designs incorporate climate-resilient and sustainable approaches to reduce flood risk, improve water quality, and enhance ecosystem services.

Expected Assignment Period (Total 48 months)

- 27 November 2025 ~ 26 November 2029 (Tentative)

Proposed Position

- Drainage and Nature-Based Solutions (NbS) Expert (10 months, Input period is not determined yet)

 Qualification Requirements

- Education: Master’s degree or equivalent in civil engineering, environmental engineering, or a related field

- Project-related experience:

1) More than 10 years of relevant experience in drainage design, water management, and nature-based solutions for infrastructure projects, including at least five (5) years of international experience

2) Experience in road/highway projects

- Experiences of working on MDB Financed Project : More than 5 years in projects financed by the ADB or World Bank or similar international organizations

Deadline of Application

- 12 October 2025

How to Apply

Interested candidates can send their CV in the ADB format to iypark@samboeng.co.kr, trantuanvu@samboeng.co.kr