Fixing drainage in flood prone Muri

Infrastructure Cook Islands is carrying out a project to overcome flooding and erosion issues in Muri.

cookislandsnews Heavy and consistent rain brings with it flooding and erosion issues – an ongoing problem in Rarotonga.

Infrastructure secretary Diane Charlie-Puna says Muri, the tourism hub of the island, is one of the several hotspots where drainage problems occur after a heavy downpour.

To overcome flooding in this area, Infrastructure Cook Islands is conducting a Aroko and Muri Drainage Improvement Project aimed at fixing drainage and stormwater improvements around the island.

Charlie-Puna said 14 culverts were identified for drainage improvement within the Muri and Aroko areas.

She said the first supply of culverts have arrived onsite in Ngatangiia and were ready for installation. The culvert upgrades will start from the Aremango stream at the Te Vakaroa and Sailing Club culverts, working upstream.

Charlie-Puna said from September 19 to October 30, the clearing of streams and widening work was completed, an approximate total of 1km was cleared along both the Aremango and Areiti streams in Muri by contractors Landholdings Ltd who were awarded the Muri Drainage Improvement Project.

Charlie-Puna said government have prioritised these major infrastructure upgrades over the past financial years to address ongoing flooding issues around the island.

In August 2019 the ministry’s Ridge to Reef project contractor Tonkin and Tailor Ltd carried out the Muri Catchment Feasibility Study for Stormwater Management.

The drainage improvement project is the implementation of the report that resulted from study.

“At this stage the improvement works aims to address drainage capacity by widening streams and increasing culvert sizes to cater for flood event,” said Charlie-Puna.

“At a later stage, attenuation and treatment which is the slowing down of flows and absorbing sediments, will be addressed by improving existing wetlands along the streams.”

Charlie-Puna said they were encouraging riparian planting (planting the areas beside waterways) along all cleared stream embankments.

In collaboration with the Muri Care Group, Infrastructure have an agreement for the riparian planting and the community will also be involved. 

Landowners near the streams are asked to not plant the banks at this stage with rauti and other plants.

“One of the major causes of culvert blockage in the areas are coconuts and kikau, dry leaves, branches and other debris. Therefore, we need to be selective at what vegetation, plants are replanted on the stream banks,” Charlie-Puna said.

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