Media release: ORC staff hold science discussions with Manuherikia catchment

over 1 year ago
Manuherikia3

Otago Regional Council met with irrigators and water permit holders in Omakau for a series of sessions to explain the science that informs the draft minimum flows.

In total, five sessions were held on Wednesday and Thursday, which focused on tributaries in the Manuherikia catchment. This included Dunstan, Lauder, Thomsons and Chatto creeks, along with a session focusing on the main stem of the Manuherikia River.

Staff from the Environmental Resource Science unit presented detailed information on the ecology and hydrology of the Manuherikia catchment.

“Following on from an initial round of community sessions in early June, we had clear feedback from the community, that they wanted to hear more about the science that underpins the draft minimum flow limits,” said Chief Executive Sarah Gardner.

“With a series of irrigation schemes, many of which originated from the old days of goldmining, the Manuherikia catchment is a complex one. These sessions have given us an opportunity to explain the ecology and hydrology of the catchment while listening to the community and verifying what we know. While the conversations have been robust and constructive, we’re happy with the number of people who have turned-out. It has made the sessions very worthwhile,” said Mrs Gardner.

Social, economic and cultural reports are yet to be completed for the Manuherikia catchment. When finalised, these reports will help determine the minimum flow limits that will be put forward for notification.

“In line with the Council resolution was that was passed on 27 June, we’ll be continuing to work with the community as we progress through this plan change, and as these reports become available,” said Mrs Gardner.

A similar science session focusing on the Upper Cardrona catchment, will take place in Wanaka next week.

Mrs Gardner made an organisational commitment to hold more meetings in order to share and understand data from irrigators.

She said, “This will inform the development of a model that will allow us to run a variety of scenarios to evaluate surety and contribute to further economic analysis. One of those scenarios will include the current minimum flow that irrigators on the main stem manage.”

The data presented to the attendees was collected from two sources: resource consents and data collected from flow monitoring and flow gauging.

Mrs Gardner concluded, “We recognise that this is not a complete data set. In order to ensure our science is as accurate as possible, we need the ongoing assistance of the community to supply the data they have and to continue attending these sessions moving forward.”

Background

Manuherikia Catchment

Minimum flows are set to provide a management regime that will look after the values of a river during periods of low flow. Low flow periods pose a “crunch time” for aquatic ecosystems as habitat and food availability for many aquatic organisms tends to decrease.

The values that a minimum flow will support in the Manuherikia catchment are:

  • Recreation, for example, swimming particularly in the lower reaches
  • Trout habitat, the Manuherikia catchment is a regionally significant fishery
  • Long fin eel, this is a specific cultural value
  • Water use for irrigation
  • Maintaining the natural character and safeguarding the health of waterways

Setting Minimum Flows

Section 30 of the Resource Management Act 1991 (RMA) requires regional councils to set levels and flows for water bodies, where appropriate.

The National Policy Statement for Freshwater Management 2014 (NPSFM) requires every water management unit to have ‘environmental flows and/or levels’ and to phase out over-allocation and ensure efficient water use.

There are a number of historic ‘deemed permits’ in Otago which provide rights to take water which have not yet been required to comply with take restrictions such as minimum flows. Under the RMA these expire in 2021 and the process of replacing deemed permits with resource consents has begun. Plan changes for catchments with high numbers of deemed permits are now prioritised to ensure as much certainty as possible for those applicants replacing deemed permits.