Project West Wind, Wellington

Erosion and Sediment Control

Tonkin + Taylor offers high levels of expertise in all aspects of erosion and sediment control. Our team has worked on major civil engineering projects, both in New Zealand and overseas.

We minimise adverse environmental effects of sediment discharge by designing appropriate and effective erosion and sediment control management systems and structures.

Specific site geology, topography and climatic environment will determine the most practical solutions that are appropriate for meeting regional regulatory requirements.


Our key capabilities include:

  • Assessment of site soil characteristics
  • Erosion and sediment control plan preparation
  • Sediment control device design
  • Chemical treatment management plan preparation
  • Flocculation systems design
  • Water discharge quality monitoring
  • Independent auditing of control devices and site practices
  • Expert evidence provision.


Our recent project examples include:

Well-Connected Alliance, Waterview Tunnel

We provided erosion and sediment control advice during the project bid phase, proceeding to preparation of many earthworks contractor erosion and sediment control plans. We also certified construction of control devices and completed weekly internal audits of the project site. Our staff successfully managed key relationships with Auckland Council compliance officers.

Hobsonville Point Schools, Primary and Secondary Schools

Tonkin + Taylor prepared an earthworks management plan for consent for a new primary and secondary school development. The bulk earthworks required 40,000m3 of cut-to-engineered fill and import of 10,000m3 of material.

Precinct Properties New Zealand, Downtown Shopping Centre Re-development

We prepared an erosion and sediment control plan to support resource consent application. This covered indicative earthworks methodologies, and erosion and sediment control measures. We also outlined suitable options for dewatering a 90,000m3 basement excavation, including winter-works contingencies and contamination risk mitigation.

Project West Wind

T+T prepared the resource consent application project environmental management plan, and provided expert evidence on the proposed sediment control measures. We also monitored water quality and developed cost-effective flocculation systems. These reflected the relatively short life of sediment control structures on wind farm developments, and the large number of structures.

State Highway 1, MacKays Crossing

We completed an independent assessment of sediment control structures at the site. This ensured they complied with Wellington Regional Council’s Erosion and Sediment Control Guidelines and project consent conditions.

Silverstream Landfill

Our team designed sediment control structures for operation of Stage 2 of Silverstream Landfill. The work involved design and construction supervision of a 35,000m3 sediment retention pond to treat landfill catchment runoff.

State Highway 1 - Paramata Duplicate Bridge

T+T developed an environmental management plan which included erosion and sediment control measures. Our team also developed suitable methods to treat sediment-laden water from bridge pile dewatering and fill material erosion around the bridge abutments. We also completed monthly audits and reported to Wellington Regional Council and Porirua City Council.

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