LocationsFlood-proofing Apia by improving drainage, thanks to the GCF Vaisigano Catchment Project in Samoa
Dealing with flooding in the capital
July 20, 2023
Aerial shot of the capital, Apia, with the Vaisigano River in the foreground, weaving its way throughout the capital, and surrounding urban areas.
Photo: UNDP/A. Hoyos
Author
LAUFĀLĒ’AINĀ LESĀ
UNDP Samoa Communications Analyst
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Samoa’s capital, Apia, is located in one of the country’s most low-lying areas along the coast. Naturally, this makes it highly vulnerable to flooding, an issue that has long been the bane of the capital’s existence.
Heavy downpours always equal inundation of the drainage systems in Apia, which leads to flooding. Businesses within these flood-prone areas in the central business district (CBD) and its periphery always cop the full brunt of these flood waters.
The floods — a serious and frequent problem — are a constant source of worry, headaches, inconvenience, and more significantly, revenue loss, for many of the businesses located in Apia.
The Government of Samoa estimated flood-related damage costs to be approximately $70 million Tala, following the last major floods of December 2020.
Flooding in the area is mainly due to Apia’s proximity to the coast, and its fairly flat location, exacerbated by existing fragmented drainage systems.
In stepped the Green Climate Fund — Vaisigano Catchment Project (GCF-VCP). From Sogi on one side of Apia, along Beach Road, right to the other end of the capital, the GCF-VCP upgraded drainage systems and outfalls in hazard areas to accommodate for flooding events.
(left) Before: This intersection at Sogi is one of the busiest in the country. But it’s also one of the most affected during flood events. (right) After: The same area from a different angle, at the completion of the drainage upgrades, now also with an improved look.
Photos: UNDP/A. Trevor
Under the leadership of the Land Transport Authority (LTA), the project has completed eight drainage upgrades in the CBD and one in the Vaisigano area (designed by the GCF-VCP, but was built and supervised under another project, the Economy Wide Integration of Climate Change Adaptation (EWACC) project, funded by the Global Environment Facility).
This has led to reduced ponding and improved safety in the targeted areas.
The GCF-VCP has also improved road infrastructure in the area with the addition of new footpaths, asphalt and slip lanes to reduce traffic congestion.
“The drainage improvements have made a difference in the everyday lifestyle of communities and beneficiaries through the improvements seen in the management of overland water flow pathways, particularly in areas that previously had no drainage systems in place. The drainage improvements, along with road upgrades and footpath inclusions, have also benefited pedestrians due to improved safety, accessibility, and convenience,” said Galumalemana Taatialeoitiiti Tutuvanu-Schwalger, Chief Executive Officer, Land Transport Authority.
Apart from infrastructure upgrades, the GCF-VCP has also equipped local contractors with new, innovative skills.
Under the project, acquired contractor experience in casting large volumes of box culverts to the required standards has resulted in reduced reliance on imported materials for construction.
Other project benefits include improved contract management services within the Implementing Agencies (IAs) with lessons learnt from managing the different construction contracts concurrently.
The project team, led by Project Manager, Tevaga Pisaina Leilua Lei Sam (middle), during the drainage upgrade works.
Photo: GCF-VCP/M. Time
The Vaisigano River has a great bearing on what goes on downstream, which includes the town of Apia. Such is the impact of the river on Apia during flood events which was why it was targeted mainly for this project for flood mitigation.
“The Vaisigano region is prone to flooding, and with increasing frequency and intensity of extreme weather events, we need to focus on flood resilience to safeguard people and critical infrastructure, and to establish overall climate change adaptation efforts. Investing in the resilience of communities and infrastructure is essential for creating safer, more sustainable environments and ensuring the long-term well-being of the catchment area,” said Lute Mundia, former civil engineer with the Land Transport Authority, who worked on the drainage upgrades.
In addressing flood risk management, the GCF-VCP has also alleviated what was a major, continuous problem for establishments and businesses in the capital.
One individual success story from this project component is the completion of the Falealili Street drainage designs that were produced through the GCF-VCP.
Consultations and social surveys revealed a clear sense of urgency and demand from the community for the project to be implemented. The project included the construction of a new drainage network and the improvement of the road along Falealili Street. This development impacted a total of 49 households and businesses in the vicinity which directed stormwater from properties to the new drainage network.
Flooding as a result of heavy rains in December 2020 (shown in pictures above) affected countless businesses and homes in the capital Apia, as well as the Vaisigano area.
Photos: EWACC Project
With a total budget of $65 million USD ($57 million funded by the GCF and $8 million by the Government of Samoa), the Green Climate Fund Vaisigano Catchment Project represents the Government’s initial steps in operationalizing an integrated, comprehensive flood management solution in the Vaisigano River Catchment Area, which includes the town of Apia.
This is all in a bid to enhance climate resilience in the area.
As with every project of this magnitude and scale, there are always challenges. From a technical perspective, these came in the form of design management and unexpected issues that arose during construction which was why coordinating together with utility agencies and contractors was important.
Construction during the rainy season also presented challenges as fluctuating tide levels influenced the working hours and schedules, requiring careful planning.
On the people side, challenges involved addressing public concerns, ensuring proper traffic management, and minimizing disruption to residents and businesses during construction. Effective communication, consultation, and grievance management were essential in overcoming these challenges.
“The upgrading of the priority drainage areas and sites in the Apia CBD has been a major, positive achievement by the GCF-VCP, with already experienced reduced flooding in significant rainfall events since their physical completion in 2021 within the Apia town areas and along main road arteries as a key component of the Stormwater Master Plan,” said Tevaga Pisaina Leilua-Lei Sam, Project Manager, GCF-VCP.
The area in front of the Mulivai Cathedral in Apia was part of the drainage upgrade.
Photo: UNDP/G. Peck
Some key lessons from this project that can be replicated elsewhere include recognizing the significance of thorough consultations and social surveys for garnering community support and identifying project priorities.
Effective communication, including household-to-household consultations, played a crucial role in addressing concerns and minimizing disruptions. Continuous improvement in tender processes, contract management, and technical evaluations can enhance project delivery for more efficient implementation.
The completion of these drainage upgrades should translate to more resilient, flood-proofed infrastructure in the capital, able to withstand the inevitable heavy rains and related risks that will continue to come in the future.
-ENDS-
