Developers fined for sediment discharge in Porirua

Developers associated with the Kenepuru Landing housing development in Porirua have been convicted and fined a total of $93,625 for unauthorised earthworks during winter, breach of an abatement notice and unauthorised discharges of sediment to Mitchell Stream.

Greater Wellington laid charges against Kenepuru Limited Partnership, Kenepuru Developments Limited, Kia Consultants Limited and Calibre Consulting Limited. They were sentenced on a total of 22 charges at the Environment Court in Wellington on 17 October 2023.

The offending occurred between 1 June 2020 and 31 March 2021. Kenepuru Limited Partnership (with Kenepuru Developments Limited as sole general partner) held a resource consent for earthworks that was subject to consent conditions, requiring earthworks to be stabilised during the winter shutdown period from 1 June to 30 September every year.

Kenepuru Limited Partnership failed to stabilise the earthworks in 2020 which contributed to significant discharges of sediment to Michell Stream, a known habitat for inanga spawning and at-risk indigenous fish species, including giant kōkopu and long fin eel. Mitchell Stream is a tributary of Porirua Stream which flows into Te Awarua-o-Porirua Harbour.

On 23 June 2020, Greater Wellington issued an abatement notice to Kenepuru Limited Partnership directing them to stabilise earthworks in accordance with their consent conditions by 7 July 2020. Kenepuru Limited Partnership did not comply with the notice and further unauthorised discharges of sediment to Mitchell Stream occurred until 31 March 2021.

Judge B P Dwyer ruled the effects of the COVID shutdown on the stabilisation programme was a mitigating factor on the defendants’ culpability and discounts were given for early guilty pleas.

In passing sentence, the Judge commented that “The issue for the Court is the cumulative effect of the myriad of individually minor discharges of sediment which is the most pervasive and significant contaminant in New Zealand’s rivers, estuaries and coastal waters.

“That is a major environmental problem in the case of Porirua Harbour and should be recognised as a factor in sentencing for discharges which ultimately end up there, even if the individual effects of any one such discharge are minor. Strict compliance with conditions of consent managing sediment output from developments in the Harbour catchment is a matter of major importance.”

Greater Wellington Environment Group Manager Lian Butcher said the regional council only pursues convictions as a last resort.

“Following non-compliance with the consent conditions and subsequent abatement order, the only way for Greater Wellington to protect the stream was through the Environment Court,” Ms Butcher said.

Greater Wellington regulates earthworks and sediment discharge under the Natural Resources Plan for the Wellington region.