The council's consent monitoring team leader John Gleeson said the person responsible was identified and abated to stabilise the site.
"The site was stabilised and infringements were issued for the initial works undertaken."
The infringements, issued in April, were related to undertaking unauthorised earthworks within five metres of the waterway and discharging sediment onto land where it could enter the water, Gleeson said.
Horizons Regional Council regulatory manager Greg Bevin said under LGOIMA (Local Government Official Information and Meetings Act) there were provisions that allowed them to withhold information about the identity of the people given the infringements.
Those provisions included protecting the privacy of a person, preventing the use of the information for improper gain or improper advantage, and "releasing the information could endanger the safety of a person".
The works themselves had resulted in a significant amount of exposed unstable surfaces which posed a risk of sediment discharge, Bevin said.
They had been finished about a week prior to coming to the council's attention.
"Our notice included an instruction to stop the works, however, as part of the abatement, they were allowed to do some works to help stabilise the site.
"It should be noted there is a track running parallel with the river and under Horizons' One Plan rules they are allowed to undertake track maintenance as long as it's not within five metres of the river."
Fines were paid in the order of $1000, with the fine level set by Resource Management Act infringement notice regulations.
The office of Te Pou Tupua, which acts in the name of Te Awa Tupua, has been approached for comment.
