Stockwater exit sparks debate over creek flows

Methven farmer John McCaw fears the council’s stockwater service exit could come at the detriment of a natural waterway intertwined in the network.

McCaw said he supported Ashburton District Council's decision to end the service in Mid Canterbury, but warned that a full closure “represents a grave threat to the future of the Mount Harding Creek”.

“It’s more than just a water race."

He is happy to see the end of the stockwater service but wants the water to still be used to maintain flows in the creek – an environmental augmentation.

McCaw’s Mt Harding Farm is cross-sectioned by stockwater races he hasn’t needed for over 10 years, but pays rates for as well as having to fence them off.

The farm is home to Drayton’s gate, where water from the Pudding Hill intake meets water from the Methven Auxiliary intake from the Ashburton North Branch.

The Pudding Hill water is swept eastwards via stockwater races while the Methven Auxiliary water turns south along Mt Harding Creek, a natural waterway that operates as a main race to connect to the network.

The council’s decision last week will close the gate to the east and have the Pudding Hill water diverted down the creek with a reduced flow from the Methven Auxiliary intake, which is next on the exit schedule.

McCaw said the decision to partially close the Pudding Hill Intake network, and allow the water to flow down Mt Harding Creek, was a “pragmatic step”.

“The council should be congratulated for acknowledging the community's desire to see an environmental flow and to keep options open for the future.”

It could only be a temporary measure as the council is in discussions with Environment Canterbury on using the Pudding Hill intake for the environmental augmentation of Mt Harding Creek once it exits the stockwater service.

The consent is for stockwater use, not environmental flows.

McCaw said Mt Harding Creek is a natural waterway in the “highly modified environment” of the Canterbury plains.

“To turn off that augmentation will simply kill the stream.”

As a custodian of the creek, one that has subdivisions around it in Methven, he wants to see it continue to flow.

McCaw accepts this would raise questions around who pays for maintenance, monitoring, and management.

“With vision and leadership, none of those obstacles are insurmountable. There are ways and means of achieving this without putting an undue rate burden on the community. “

Te Rūnanga o Arowhenua, which sits on the stockwater group, has requested that water no longer required for the stockwater network remain in the source rivers.

Deputy Mayor Richard Wilson, who chairs the stockwater transition working group, said any environmental augmentation work will not be done by the council.

“We are happy to facilitate this discussion by all those who want water to stay in the creek for ecological and aesthetic reasons.”

He said properties that still need stockwater are encouraged to talk with Barrhill Chertsey Irrigation (BCI) about accessing water.

The council signed an agreement with the irrigation company. The company is willing to work towards offering a service, with the cost of providing that service between landowners and BCI.

BCI chief executive Nick Daniels said he supported best transition from council services to alternatives but raised concerns about community readiness and the council's timetable.

The drainage dilemma

The deputy mayor said the council is looking at alternative providers to either take over schemes or provide opportunities to connect to piped networks for those needing the service.

“The landowner has the right to fill in the dry race if they wish. It is their choice.

“Stormwater follows the natural contour of the land. Infrastructure is put in place by council, ECan, and landowners to mitigate the damage. This will continue.”

At the council meeting, assets manager Andy Guthrie said there are complexities with changing the races from stockwater to stormwater assets.

“We can’t just simply leave a race open and say it's for stormwater purposes.”

He said the preferred approach is for landowners to fill races in and then identify where drainage issues occur.

“It would be far more effective to do that post-closure than to try and predict it pre-closure.”

McCaw was at odds with retrospective flood management, calling for “a moratorium on filling in races until a proper drainage plan can be established”.

“I’m not sure they have heard the message yet about drainage,” McCaw said.

“There is a lot more work to do to ensure a functioning network of drains is maintained.

“We’ve had the benefit of those races for that reason for many years.

"It’s scary to think what it might look like if they get closed in.”

The partial closure of the Pudding Hill intake network was the first decision in the exit process and the council has 17 more intakes to work through in the next 18 months to meet the end of June 2027 deadline.

Wilson said the exit process “is on schedule”.

By Jonathan Leask