Waikato, Waipā and West Coast erosion and sediment reduction

Flood resilience programme
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  4. Coromandel Peninsula erosion and sediment reduction

Funded: $1.68m (Regional Investment Fund, administered by Kanoa – Regional Economic Development & Investment Unit)
Total project cost: $2.8m

Project Information

The severe weather events of 2022, 2023 (including Cyclone Gabrielle) and early 2026 Boom Stream before rock groynes were installed on the outside bend caused widespread and longlasting environmental and infrastructure damage across the Coromandel Peninsula, leaving its communities economically strained and – at times – isolated.  

The Coromandel Peninsula Erosion and Sediment Reduction project extends flood mitigation work to remediate waterways severely impacted by these weather events.  

Work includes a mix of soft and hard engineering methods to control erosion, the removal of blockages and debris in waterways, and fencing and planting riparian margins to improve streambank stability during heavy flow. 

The increase in frequency and intensity of heavy rain events and rising sea levels, combined with the low elevation land-sea interface and short, steep catchments of theBoom Stream after rock groynes were installed on the outside bend Coromandel Peninsula, is increasing flood and erosion risk for its communities.  

The repair and prevention of damage caused by these events is often cost-prohibitive for individual landowners, although the impacts and benefits are widespread. 

This project is being funded by the Regional Investment Fund (RIF), Waikato Regional Council and landowners. 

Project Benfits

  • Improving and enhancing channel capacity, reducing streambank erosion and riparian planting will safeguard agricultural land from flooding, enabling productivity and minimising economic losses associated with flood damage. Debris Pile Collected From Parakau Stream

  • Reducing erosion and sedimentation supports water quality outcomes for aquatic ecology, recreation, fishing and the aquaculture industry.  

  • Delivering economic benefits by protecting agricultural land, lifeline and key roading infrastructure, tourism values and small communities, which are vital to the Coromandel Peninsula's economy and social fabric.  

  • Creating employment opportunities for local contractors, ensuring economic resilience and growth. 

Rock revetment work on the Wharekawa River
Rock Revetment Wharekawa River
[1/2] Rock revetment on the Wharekawa River close up