Nuku'alofa, flooding. 4 March 2013.

By Pesi Fonua

The flooding in parts of Nuku'alofa is a testimony to an ad-hoc decision-making process that has been taken in the urban development of Nuku'alofa, Tukua Tonga, the director of the Urban Planning Unit of the Ministry of Land, said today.

Flooding during this week's heavy downfalls of rain, has closed some schools and businesses, made roads impassable, and caused community concern over the rapid breeding of mosquitoes in stagnant drains and around flooded septic tanks.

When asked to comment on why a new multi-million pa'anga drainage system was apparently not working in many busy parts of the capital, Tukua said that there had been a failure to integrate the current civil work, which had yet to be completed, with plans and studies that have been carried out over the years to improve the standard of living in the Nuku'alofa urban areas.

He said a comprehensive report, the "Urban Planning and Management System" was launched in May 2010, with technical assistance from the Asian Development Bank and funded by the Japan Special Fund.

The report identified that wastewater management was a substantial concern. It proposed the preparation of a comprehensive sanitation and wastewater management master plan.

"The plan will consider the feasibility of phasing out the use of soak-aways and to interconnect septic tanks to sustainable village-based communal or area-wide centralized wastewater collection and treatment systems," he said.

Overseers

Tukua said that because of the current flooding of residential areas and the blockage of the drainage system, he had been trying to organize a meeting with officers from the Ministry of Infrastructure who are responsible for overseeing the civil work that is currently being carried out.

"But so far we have not been able to set a date for a meeting."

Tukua said that the only other option left for him and his Ministry was to stipulate the National Spatial Planning and Management Act 2012, which gives the Minister of Land the right to stop the work if it endangers the livelihood of the people.

Meanwhile, the CEO of the Ministry of Infrastructure, Ringo Fa'oliu, told Radio Tonga yesterday that the drainage system would work once the construction of roads and drains was completed.

High risks

Back in May 2010 the Urban Planning and Management System Report,  that aimed to improve the standard of living in Tonga's urban areas, pointed out that: "In Nuku'alofa there is an acute lack of drainage systems … and the drainage systems that are currently in place do not function well … and the retention period of flood water sometimes takes days.

"During these periods the city becomes an extensive breeding ground for mosquitoes, putting communities at risk of acquiring dengue or malaria."

The report went on to warn: "flooding exposes the people and water wells to risk of contamination with raw sewage and associated diseases, e.g. leptospirosis, dengue, malaria, typhoid and other intestinal and skin diseases."

There is no sewage system in Nuku'alofa, where septic tanks, flush toilets and pit latrines discharge their effluent through vertical soak-aways into the soil underground.

The report pointed out that flooding also disables economic activities and immobilises the flow of people, goods and services, and causes damage to properties.

Lagoons under stress

Unmanaged storm water drains into either to the sea or to the Fanga'uta Lagoon, which are receiving loads of pollutants that come with the storm water. "The lagoon is reported to be in a state of stress from nutrients and pollutants."

The report also noted that global climate change had resulted in rising levels of high tides that sometimes occurred with heavy downpours causing backflows in the Nuku'alofa systems.

Roads projects need drains

Citing all these facts, the report strongly recommended that the drainage components of the CBD reconstruction project and the China Government's Community Roads Upgrading Project phase 1, along with the Integrated Urban Development Sector Project, needed to be reviewed.

"To address the drainage concerns in Nuku'alofa, it should first be a rule to require all road projects to incorporate drainage provisions to agreed standards," it stated in 2010.

The flooding is expected to get worse every year. The report estimated that water demand in Nuku'alofa would double in the decade 2010-20 and therefore greatly increasing the amount of waste-water to be disposed of.