Are we facing another very dry period for the summer of 2026/27 due to a change from La Niña to El Niño?
The latest ECMWF seasonal forecast system (SEAS5) indicates a heightened likelihood that El Niño conditions will develop during 2026 and persist into the 2026/27 summer, although there remains uncertainty regarding the eventual strength of the event due to the spring predictability barrier. Current model guidance shows a transition from ENSO‑neutral conditions to El Niño during the second half of 2026, with El Niño the most likely ENSO state through summer 2026/27.
An intensifying El Niño, combined with rising temperatures driven by climate change, is expected to significantly increase the risk of very dry conditions across parts of New Zealand.
In New Zealand, El Niño conditions are typically associated with more frequent westerly airflow, leading to enhanced rainfall in the west of the country and a greater risk of dry conditions in eastern regions, including Otago, Marlborough, Hawkes Bay, Canterbury, etc. During stronger El Niño events, this pattern can substantially reduce rainfall and river inflows from non‑alpine catchments. While the extreme global impacts often highlighted by international agencies are less likely to occur locally, El Niño can place significant strain on water demand and supply, particularly for foothills‑ and rainfall‑fed systems, where restrictions can be prolonged during dry summers.
The influence of El Niño on atmospheric circulation tends to be strongest from December through February, coinciding with the peak of the irrigation season in Canterbury. At this stage it is too early to state with confidence that summer 2026/27 will be a drought, but historical experience shows that some of Canterbury’s most severe droughts have occurred during El Niño years, including 1972–73, 1982–83, 1997–98, and 2015–16. When historical climate data are combined with current levels of irrigation and municipal demand in water‑supply simulations, the summer of 1972–73 consistently emerges as one of the periods of greatest stress on regional water resources.
Following the 1997–98 drought, the Canterbury Strategic Water Study, commissioned by the Canterbury Mayoral Forum in response to concern that Canterbury’s water resources were under unsustainable pressure, found that while the region has sufficient water overall, it is often unavailable at the right place or time. Water storage is therefore critical for managing seasonal variability. Although some progress has been made, gaps remain – particularly in preparing for severe El Niño‑related droughts – and improving short‑term resilience also supports long‑term climate change adaptation. The situation in other east coast regions is likely to be similar: the national-scale assessment of Water Availability and Security commissioned by MPI in 2021 found that opportunities for expansion of high-value land uses with sufficient resilience to climate variability and change would likely depend on the development of storage-based water infrastructure.
Experience from the 2015–16 El Niño drought illustrates this clearly. Irrigators supplied from alpine river systems generally coped well, especially where access to stored alpine water was available. In contrast, many foothills‑sourced schemes were subject to full or partial restrictions from Christmas through to late summer. The following irrigation season highlighted a compounding risk: successive summers with high water demand and limited winter recharge placed considerable pressure on groundwater levels, reducing system resilience even in less extreme climatic conditions.
While there is uncertainty around the precise conditions that will prevail in summer 2026/27, the emerging ENSO signal suggests that a more precautionary approach to water management is warranted. Managing demand early in the season as if drought is a possibility is prudent. Unlike floods, droughts develop slowly and are often well advanced before their impacts are fully recognised. Water users operating under annual volume limits should closely track usage, as the likelihood of allocations being fully utilised – or constrained by restrictions – is higher in El Niño‑influenced summers.
The importance of irrigation performance checks.
Performance checks are also important to meet Farm Environment Plan requirements associated with your property land use consent, you need to demonstrate that your irrigation system is designed and operating efficiently.
Far from an average irrigation season
The 2025-26 irrigation season has shown us once again that there’s no such thing as an average when it comes to describing the climate factors that drive irrigation demand and supply.
Do your effluent ponds leak? How do you know?
Most dairy effluent storage pond owners believe that their ponds are not leaking, particularly those that have been synthetically lined.
Measuring Water to Manage it Well
From September 2026, all water takes greater than 5 litres per second will need to be measured and recorded every 15 minutes, and the data telemetered directly to the Regional Council.
Renewing Your Resource Consent
The article I wrote for the last Canterbury Farming publication generated much interest and feedback.
Renewing Consents
The end of 2025 brought news of a huge amount of proposed change in the resource management space – too much to cover in one article.
A New Chapter for Farming Resource Consents
The major overhaul of the Resource Management Act (RMA) introduces two replacement laws: the Planning Bill, focused on enabling development and land use, and the Natural Environment Bill, dealing with environmental protection and management.
Understanding Source Water Risk Management Areas (Drinking Water Supply Protection Zones) and What They Mean for Rural Landowners
Source Water Risk Management Areas (SWRMAs) are becoming an increasingly important part of New Zealand’s drinking water safety framework, and for rural communities in particular, they can have real and lasting impacts on how land is used.
Consents – they need your attention!
Consent renewal isn't automatic. Understanding what councils are looking for and getting your application right matters more than ever.
We got off lightly, this time.
In Canterbury we’ve been fortunate to have been spared from the drought conditions that have been experienced over the 2024/25 summer in the top of the South Island and parts of the North Island, although parts of North Canterbury have been very dry at times.
Leaky effluent ponds? Prove it!
One of the drivers for proving that effluent storage ponds are not leaking, is the need for farms to operate at a minimum of Good Management Practice (GMP). Ideally the farming operation should be operating at better than GMP.
Will your irrigation consent be renewed?
Consent holders are now frequently asking questions about the renewal process and whether it is going to be possible to renew their irrigation consent.