Tiritiri Matangi Island Conservation Work

Tiritiri Matangi Island is a wildlife sanctuary and internationally acclaimed conservation project 3.5km off the eastern end of the Whangaparāoa Peninsula.

The sanctuary is managed by the Department of Conservation in partnership with the Supporters of Tiritiri Matangi, a voluntary community group and major contributor to the success of Tiritiri Matangi as a wildlife sanctuary. The island is home to some of New Zealand’s rarest birds including:

• red-crowned kākāriki
• tīeke (North Island saddleback)
• pāteke (brown teal)
• pōpokatea (whitehead)
• takahē
• toutouwai (North Island robin)
• kiwi pukupuku (little spotted kiwi)
• hihi (stitchbird)
• North Island kōkako
• mātātā (North Island fernbird)
• tītīpounamu (rifleman)
  

Other native fauna on the island includes tuatara and species of skink and gecko. Invertebrates include the introduced and endangered wētāpunga. Freshwater fish include longfin and shortfin eels.

The Supporters of Tiritiri Matangi engaged Hick Bros to carry out some much-needed civil works on Tiritiri Matangi Island. This included metalling of access tracks, surface drainage, cross culverts etc and cleaning silt, vegetation and other debris from some old water storage ponds on the island. In order to do this, Hick Bros barged a digger, skid steer and a roller compactor and a 4wd site vehicle to the island to complete the works. Metal, second hand pipes etc were also taken to complete the works. The instructed works took about 2 weeks to complete.

While Hick Bros staff were on the island, they found that most of the ponds didn’t hold water in dry periods or leaked significantly and that it was a major problem for the island because it had no standing water during dry periods for the wildlife. Island staff had to put out water in trays for the wildlife during dry periods.
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On further investigation we found that there was no readily available clay on the island to seal the ponds and that the underlying bedrock was fractured and permeable which was the cause of the ponds leaking. Following this, Hick Bros staff, wanting to add to the good work that was being done by volunteers on the island, took a proposal to the Hick Bros Board of Directors which included the installation of a geosynthetic clay liners (GLC) in 4 of the ponds to stop the leaking.
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The Board of Directors agreed to fund a return to the island and cover all costs to supply and install a GCL in the leaking ponds as a contribution to very important wildlife project. The Hick team again barged plant, materials and staff to Tiritiri Matangi Island and successfully performed the remedial works. As a result, the island now has reliable free-standing water for the wildlife during dry periods.

Hick Bros is very proud to be associated with this outstanding conservation project.

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