Earthworks contractor fined for 2018 Raglan harbour discharge

Hamilton based earthworks contractor, Pemberton Civil (Hamilton) Limited, has been convicted and fined $110,000 over sediment-laden stormwater discharges that killed shellfish and seagrass in the Raglan Whāingaroa Harbour in 2018.

The sentence for unlawful discharges of contaminants was delivered by Judge David Kirkpatrick from the Hamilton District Court on 20 November.

The prosecution, taken by Waikato Regional Council under the Resource Management Act, arose from incidents which occurred in the early stages of the Rangitahi Peninsula residential development.

Pemberton Civil (Hamilton) Ltd were contracted to complete the earthworks for the development site which included installing erosion and sediment controls. The development site had been recognised as high risk by the council due to its proximity to the Raglan harbour and its steep coastal terrain. As a result, additional requirements had been imposed for the sediment controls, which the council investigation discovered had not been undertaken.

Four of the sediment controls failed over several days in July 2018, two of these being stormwater detention and treatment devices situated on the escarpment above inner reaches of the Raglan harbour. These failures resulted in substantial volumes of sediment laden stormwater being discharged into the tidal reaches of the harbour around the Rangitahi peninsula.

The sediment discharged into the Whāingaroa Harbour and coated the marine environment in an orange sludge that was visually offensive and ecologically fatal for shellfish and seagrass in the vicinity. 

The impact on the environment, iwi and Raglan community was significant.   

The council’s Regional Compliance Manager Patrick Lynch said: “Whāingaroa is a treasured environment for the Raglan community and iconic in the Waikato and beyond. We all need to have confidence that residential developments, such as this one, are carried out sustainably.   

“This case has been a very protracted process, taking more than five years to get to this point, and the development at Rangitahi has advanced considerably in this time. On a positive note, we are not aware of any other such events occurring since those early stages,” Mr Lynch said.

Repairs underway to failed sediment control – 17 July 2018.

Tidal area impacted by sediment control failure – 3 August 2018.

Sediment control failure in coastal escarpment – 19 July 2018.

Sediment spread through harbour – 3 August 2018.