A Bay of Plenty company carried out unlawful earthworks at a Te Puke kiwifruit orchard which led to the discharge of sediment-contaminated stormwater into a Kaituna River tributary.
The Bay of Plenty Regional Council says it was likely that suspended solids from the two discharges would have eventually discharged into the Kaituna River.
The river is an important habitat for indigenous fish species and threatened flora and fauna, and a whitebait spawning site, and highly valued by local iwi.
In the Environment Court in Tauranga on Tuesday, G & J Vercoe Contracting Limited pleaded guilty to two charges of using land in a manner that contravenes the Bay of Plenty Regional Council's Water and Land Plan.
The council's prosecution case relates to the company carrying out earthworks at a kiwifruit orchard, owned by Maketu Estates, on Gridley Rd, Te Puke in 2016 and 2017 without resource consents.
The company's offending was detected by a regional council enforcement officer during an inspection of the property on May 12, 2017.
The officer discovered a highly discoloured flow of stormwater coming from one of the two earthwork sites from a channel cut through the fill which leads to the Kaituna River.
In early 2017 Maketu Estates again engaged the defendant company to undertake more earthworks to bench the second gully at the same property.
Following a complaint, a regional council enforcement officer visited the property and ordered the works to stop until a resource consent was obtained.
About 2000 cubic metres of earth had been moved without erosion or sediment controls.
Before a resource consent application could be lodged and granted, an extreme storm happened in April 2017, and the sediment and erosion controls put in place failed.
That led to a discharge of sediment contaminated stormwater into the watercourse.
Council said the earthworks were likely to have added to the cumulative impact of sedimentation and erosion in the Kaituna River catchment, including Maketu Estuary.
Victoria Brewer, a lawyer for the regional council, told Judge David Kirkpatrick that given the scale of the offending, total fines of almost $30,000 were being sought.
Brewer said the offending was at "very least, extreme recklessness" by a highly experienced operator who ought to have known resource consents were required.
The defendant's lawyer Deborah Riley argued that this was a case of "carelessness" rather than a deliberate flouting of the rules by her client.
The defendant "got it wrong on this occasion" and had made changes to its operating practices to ensure it does not happen again, she said.
Judge Kirkpatrick reserved his decision.