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Nuku'alofa's new roads and drainage not sustainable, warns report

Nuku'alofa, Tonga

Flooding at Hala'ovave, Nuku'alofa. 14 June 2016.

By Pesi Fonua

Improvements to Nuku'alofa's roads and drainage, under a successful multi-million project started in 2008, are "less than likely to be sustainable" if they are not properly maintained, warns a report released by the Asian Development Bank.

"There is a lack of evidence that the government has recognised the importance of maintenance of the improved assets," the report concluded.

Continual maintenance and cleaning of the new drainage system is considered to be essential by the engineers who designed it. Otherwise, the drains will not be able to relieve all the unsanitary flooding quickly, during periods of heavy rainfall over Tongatapu.

The report also reveals that cancellation of drainage plans and reallocation of funds from core projects had compromised the goals of the five-year development project.

The Sopu drainage channel was cancelled and funds were reallocated from high-priority core projects to non-core subprojects in the $13.4 million Tonga Integrated Urban Development Sector Project, started in 2008 and completed between 2013 and February 2015.

These were among the findings of a validation report assessing the project, prepared by the Independent Evaluation Department of the ADB and released in October 2016.

The project was financed with an $11.26 million loan/grant from the Asian Development Bank, and $2.11 million input from the Tonga Government. While the validation report recognized that the performance of the borrower was satisfactory and efficient in achieving the general outcome, at the same time it did not agree with a Project Completion Report that claimed the outcome was sustainable.

Football fields under 'Apifo'ou College lake. Flooding in Nuku'alofa, Tonga, 11 June 2016.

No commitment

Citing a "lack of evidence" of a commitment by government to meet the operation and maintenance costs for the upgraded roads and drainage systems, the project was instead validated as “less than likely sustainable” by the independent assessors.

They noted that changes to the plans, overlaps with a Chinese-funded aid project and reorganisation of the government's Ministry of Works that was executing the project, had created unfortunate set-backs for the roads and drainage project that aimed to improve living conditions for some of Nuku'alofa's poorly situated settlements.

"The project was highly relevant to government and ADB policies and strategies but weaknesses in project design and mitigation strategies for known risks limited the project's relevance and its effectiveness in achieving project objectives," the report stated. "The impact of training was constrained by heavy staff turnover…[and] securing the necessary financial and human resource support may prove challenging."

Unplanned growth

The multi-million urban development project was initially planned because, at the time, the development expansion in Tonga's capital had been driven by ad hoc projects leading to unhealthy settlements on unsuitable low-lying wetlands. Frequent flooding in parts of Nuku'alofa had resulting in declining health and social indicators.

In response to these poor living conditions, the Tonga Integrated Urban Development Sector Project aimed to improve environmental quality and public health in Nuku'alofa through improved urban infrastructure.

Expected outcomes

The project was expected to result in three main outputs in core areas:

  1. Roads – efficient and well-maintained primary road network;
  2. Drainage – well-maintained and functional drainage systems;
  3. Sanitation – monitored groundwater quality and assessed impacts of septic tanks on aquifers underlying Nuku’alofa.

It was expected that through improved drainage the cases of waterborne diseases such as diarrhea, along with dengue fever and typhoid fever could be reduced. It also aimed to reduce traffic accidents and reduce vehicle-operating costs by improving roads, particularly in low-income and low-lying residential areas.

Tonga’s Ministry of Works was the executing agency and responsible for the overall implementation of the project. Unfortunately, during the implementation period, MOW went through a reform process and merged with the Ministry of Transport to form a single ministry – the Ministry of Infrastructure. This involved the movement of some key MOW personnel, some of whom had been working with the project.

It was a set back for the capacity-building objective of the project and reduced the size of the operational unit,” according to the validation report.

There were also other changes and missing information, and even though the project was completed on time and within the approved budget, casting doubts over whether it can be maintained in future.

Sopu drainage

Flooding enters the home of ‘Ilaisaane Lomu and her children at Tongata'eapa, Nuku'alofa. 14 June 2016.

The Sopu drainage channel was highly relevant to the government and the ADB but it was cancelled.

This happened when it was found there was an overlap between the drainage rehabilitation and maintenance component of the grant and the Nuku’alofa CBD Reconstruction Project. The overlap led to the cancellation of a significant part of the drainage rehabilitation subproject. The validation report suggested that this overlap could have been foreseen by the designers of the [other] project funded by the People’s Republic of China.

Difficult land acquisition at Sopu also contributed to the cancellation of the drainage channel.


The validation report recommended that maintenance of project roads and drains is necessary to ensure long-term sustainability, that the focus on adequate and timely maintenance should be emphasised, and effective use of project-financed equipment should be made at all times.

"It is emphasized that the Ministry of Infrastructure should ensure that regular maintenance work is carried out to safeguard long-term sustainability of the Infrastructure and that adequate budgets are allocated at all times for regular Operation and Maintenance of the road and drain-cleaning equipment provided under the project."

While stating that "it is likely that the economy of Nuku'alofa and the wider surrounding region directly and indirectly benefited from the project", the validation also pointed out that "insufficient data was available to fully assess the project's performance," and that related data collection needed more emphasis.

Reference: 'ADB Validation Report PVR-457, Project 38160-032. Tonga: Integrated Urban Development Sector Project.' Independent Evaluation Department, Asian Development Bank. October 2016.

Related articles:

Nuku'alofa flooding to drain faster

Flooding exposes Nuku'alofa's sanitation crisis

ADB provides $11.3M grant to improve urban infrastructure in Nuku'alofa


Creating drainage, as was proposed by ADB, for the inhabited Sopu mangrove area by creating a channel was entirely ill-conceived.
Refer to the above article with the following points:
1. The reconstruction of the CBD and the ADB Urban Development Project were never directly connected in any way.
2. The Maintenance of drainage in the CBD was to be provided under the EXIM Bank of China soft loan by providing equipment to maintain the same.
3. Creating drainage, as was proposed by ADB, for the inhabited Sopu mangrove area by creating a channel was entirely ill-conceived. The area is wet because it is at sea level! In fact this area is historically connected with the Fanga’uta lagoon. You can’t drain the ocean to the ocean.
4. With regard to the ADB project of testing groundwater under Nuku’alofa (with the assumption that septic and other contaminants will contaminate the same at Mataki’eua?), is ill founded at best. To assume that the elevated parts of the groundwater lenses at Mataki’eua and onTongatapu will get backflow from Nuku’alofa contravenes the laws of physics (water does not run up hill). This is further corroborated by studies by Lao and Hunt 30+ years ago on the nature of the Ghyben-Herzberg fresh waster lenses on this island. Further, if groundwater is contaminated under parts of Nuku’alofa, as it undoubtedly is, there is little or nothing that can be done about it.
One has to wonder who is thinking what and for what reasons.- Richard Stoll

The equipment used in the CBD project to rehabilitate the drainage (a street sweeper and the truck mounted suction pump and tank) were supplied under the ADB project, but the work was part of the Civil Works included in the China loan programme.
The resealing the CBD streets with an asphalt overlay was carried out with product produced by a new asphalt plant and paver (have they been used since?) supplied under the China loan, but this was after I had left as project administrator. The result was some rebuilding projects were shelved. - Paul Karalus.