What’s the story about Greenstreet Creek

It’s been six months since the low flow event at Greenstreet. The additional water diversion to the irrigation channel and subsequent creek ended in July following winter rain. 

Although the channel is currently flowing well, we are already talking to irrigators and landowners about what will happen if dry conditions return.  

We’ll also be talking about Greenstreet at the Ashburton Water Zone Committee on Tuesday 24 September at 1pm if people would like to come along  (held in the Ashburton District Council Chambers).

In the meantime, here's a quick update from Judith Earl-Goulet, General Manager Catchment Implementation in our Water and Land team.

Being prepared to help protect biodiversity in future dry times 

Looking after native biodiversity across Waitaha/Canterbury is important and we appreciate every member of the community who goes above and beyond to protect our unique species, like native fish and tuna/eels.  

Dry conditions are expected more frequently in the future and, over time, waterways like Greenstreet may not continue to flow. If this happens, we won’t be allowing additional water to be diverted from other streams, beyond what is consented. 

We’re planning well ahead of dry times to ensure help is available for those who have the Greenstreet channel going through their properties and we are happy to visit in person over the next few months. Get in touch via our advisory team on 0800 324 636.

We’ll be able to talk about the freshwater ecosystem of the channel and how people can be ready for any future fish rescue operations if needed. We’re also keen to hear ideas from the community on how we can work together more closely in this catchment going forward. 

Adding more water from other streams isn’t always possible

We understand that many in the community may want us to keep adding more water from other streams, like we did earlier this year as a one-off temporary measure. The reality is that in dry seasons, there isn’t enough water to maintain minimum environmental flows in our natural waterways and top up waterways from irrigation channels that are becoming dry. 

Our approach will remain in line with the agreed planning framework to keep water in natural creeks and rivers. For example, the lowering of the minimum flow at Greenstreet helps support O’Shea Creek, one of the sources of Greenstreet’s water and a natural fish refuge.

Summing up the Greenstreet approach this summer 2024/25 

We have a plan for preparing for dry weather and low flows and are happy to visit landowners to talk about this; 

The irrigation society is aware that another temporary diversion of additional water from O’Shea Creek won’t be allowed; 

Current rules will remain in place across the area and in many cases this will mean less water available for irrigation in dry weather. 

We will be ensuring compliance with consent conditions that are in place and supporting consent holders if they would like to explore different options for water allocation under the Land and Water Regional Plan.  We will begin to consider a new integrated plan in 2027, which will include a review of the Ashburton River planning framework.  

Chief Executive Dr Stefanie Rixecker has made the decision to allow water to be diverted into Greenstreet Creek.

We know the community’s frustration regarding the recent fish strandings at Greenstreet Creek and acknowledge we haven’t kept the community well informed.

The bigger picture is that we are amidst the impacts of the El Niño weather pattern and climate change, here and now, and we’re seeing very dry riverbeds across Canterbury.

Added to this, we’re the largest region in the country, with the greatest number of rivers and freshwater sources (78,000km of rivers and streams; 70% of the country’s groundwater) – we’re water central of Aotearoa New Zealand.

This means challenges and the need to make trade-offs – tough calls that weren’t made by previous generations are here and now.

The Ashburton River/Hakatere is an over-allocated catchment with significant challenges, including natural changes in modified environments. We recently undertook water take consent reviews on this part of the Ashburton River/Hakatere, precisely because of these challenges.

The decisions that came from the water take consent reviews are what our team has been working through and grappling with in this particular case. These changes are tough on communities who deserve better conversations about the changes.

Better approach needed to support community

We need a better approach to “just transitions” – supporting our region to adapt to the effects of climate change in as fair a manner as possible.

As Chief Executive, I’m making the call to allow water to be diverted into Greenstreet Creek.

I’m making this decision in the face of climate change and in recognition that we didn’t get the “just transition” conversation right; we own that.

This is not the only place in Canterbury where we will face a challenge like this, but we must work better with our communities and landowners, our rūnanga partners, and the wider public.

The diversion is the immediate action in this current situation. However, future conversations need to happen about how we recognise the needs and interests of the community, our rūnanga partners and the environment itself, to make the hard calls together.

Lastly, I'd like to acknowledge the fish salvage work undertaken by Fish and Game and the local community over recent days – thank you.

While our local team has been responding to landowners and impacted consent holders about this issue, we hadn’t updated the wider community and we’re sincerely sorry for this omission – we could have responded to community concerns with this information much sooner.

Restrictions and rules are in place

Regrettably, there has been a loss of aquatic life in this stream and we acknowledge the fish salvage work undertaken by Fish and Game and the community. There are irrigation restrictions and consent conditions that are in place to protect the overall water quality and flow across the wider Ashburton River catchment – so allowing additional water into this creek it is not a straightforward request.  It’s also unlikely that adding additional water at such a dry period would provide anything other than a very temporary solution. 

Taking all of this on board – we are immediately addressing how we can work better, and update the community faster, when we become aware of incidents like this.

All rivers in the Ashburton catchment are currently on full restriction. This means consent holders are prohibited from taking water from any waterway in the catchment, regardless of the purpose. In the coming months, if sufficient rainfall occurs, we would then expect to see water naturally in the creek.

Protecting the Hakatere/Ashburton River catchment

Minimum flows were established during the Ashburton River plan development (made operative in 2015) with the community to protect the waterways’ values and for people and the environment within the Hakatere/Ashburton River catchment.

The Ashburton water consents review was carried out in 2018-2022 to implement these minimum flows on consent conditions. New minimum flow restrictions became effective from 1 July 2023 for all consent holders within the Ashburton catchment. The Ashburton consent review process did anticipate that such circumstances would occur from time to time, and with it also being a very dry year, the impact of that consent review has been felt sharply. The review was supported by the Ashburton Water Zone Committee.

Irrigation restrictions in place

It should be noted that winter 2023 and early spring were relatively wet compared to other years. However, climate conditions have shifted to El Niño and, as a result, the past few months have been warm and dry. With the lack of significant rainfall and lack of snowmelt (from a dry winter) occurring, river flows are decreasing throughout the region, especially in all our foothill and lowland rivers.

Many river flows are below their minimum flows and most consent holders are on full restriction, including the tributaries and mainstem of the Ashburton/Hakatere River. The temporary discharge of water such as that requested by the consent holders of Greenstreet Creek would not be a long-term solution to protect instream life such as tuna and fish.  

A continual water take and release to Greenstreet Creek would be needed to augment the creek even then, due to dry conditions in the catchment, there would be no guarantee that the flow from Greenstreet Creek would be sufficient to allow connection with mainstem Ashburton flows.