Holcim New Zealand: Habitat restoration.

Rejuvenating native habitats through thirty years of progressive rehabilitation

Continuous monitoring and compliance with the conditions of the operating license are essential requirements for on-going quarry operations. In addition, Holcim New Zealand believes that well managed rehabilitation work can deliver environmental benefits, help secure future consents to operate, and build stakeholder trust.

The area surrounding the Cape Foulwind quarry and Westport plant has long been subjected to extensive habitat clearance, including significant deforestation for development and agriculture.

The plant has a long history of progressive rehabilitation in the “spent” quarry areas since 1980, resulting in rejuvenation and the establishment of indigenous biodiversity. Building on these efforts, the plant has developed, with extensive external stakeholder input, a new plan aiming to rehabilitate the site by 2043 to habitats that existed prior to development.

Project description:
Since 1957, the Westport cement plant operates the 120 hectare Cape Foulwind quarry in the West Coast of New Zealand’s South Island.

As a result of plant’s rehabilitation efforts, coastal vegetation has, to a certain extent, been reestablished in the area. Today, the quarry and adjacent Tauranga Bay are home to colonies of endangered New Zealand Fur Seal and Little Blue Penguin. A wetland catchment area provides habitats for many threatened species, such as the Long Tailed Bat (Chalinolobus tuberculatu), White Heron (Ardea alba Modesta) and Grey Duck (Anas uperciliosa).

Building on these results, Holcim New Zealand is now working towards rehabilitating the entire site into a landscape consisting of indigenous forest, a lake, and wetlands.

Little blue penguin

Objectives:
The overall goal of the rehabilitation project is to create, by 2043, a mosaic of indigenous forest and wetland communities similar to what in all likelihood existed prior to the land use changes. Once the work is complete, the ultimate aim is to make it a self-sustaining ecological unit.

Activities:
With expert advice from universities and NGOs and in consultation with local communities, the
rehabilitation plan follows four guiding principles:

  1. Focus on restoring original native habitat supporting native fauna species
  2. Human interference should be minimized
  3. Rehabilitation should be part of the routine operation of the site, to support the reprogressiveestablishment of native species.
  4. Costs must be well managed and sustained

Four zones were delineated reflecting the main habitat types in the area:

  • The coastal zone;
  • The wetland zone,
  • The quarry zone;
  • The inland zone of land adjacent to the road, including farmland.

The company involves local stakeholders in conducting some of the activities. For example, in the inland restoration zone, neighbouring farmers have been engaged to monitor water quality and soil composition. An onsite nursery was established to cultivate indigenous species for the rehabilitation works under local conditions providing 50,000 plants per year. The nursery is run by local residents and also sells plants to the community. The monitoring data and site activities are regularly reviewed by environmental scientists and the plans are revised accordingly.

Additionally, Holcim supports research by Lincoln University on the breeding and fledging success rates of the West Coast Blue penguins and provided funding for nesting boxes and predator control.

Results:
Systematic rehabilitation efforts have resulted in steady progress towards a self-sustaining ecosystem. Rehabilitated and regenerating bushland now covers over 60 ha of Holcim company land. Studies indicate that native plant species (e.g. Kahikitea and Totora) are re-established. The composition and abundance of ground-dwelling invertebrates in rehabilitated areas has been found to be healthier than in nearby non-restored sites. A range of new habitats for native biodiversity has been developed, enhancing ecosystem functioning. Moreover, the combination of restored areas and native forest remnants enriches the aesthetic appeal of the quarry area.

Rehabilitated site at Westport plant

Learning:
This project demonstrates the importance of progressive rehabilitation. The fact that ecological restoration takes time should be factored into management plans accordingly. Scientific data relating to soil, water and wildlife presence is required to set appropriate and achievable targets. In order to ensure the long term viability of a restored site, emphasis should be placed on reestablishing the native flora through a collaborative, consultative process involving appropriate experts and community groups.