Keeping your irrigation system up to scratch

Keeping irrigation systems well maintained throughout the year is crucial to ensure good management practice is followed, and water use is sustainable throughout the irrigation season.

Waimakariri and Hurunui Waiau Zone Delivery Lead Marco Cataloni says there’s been some unusual weather this summer.

“The conditions have created uncertainty for farmers trying to plan, cultivate and store winter feed in preparation for the next season change, and continue to grow crops for food, fibre and their whānau over summer – all of which requires irrigation,” he says.

Working together

Many of our farmers have been working closely with industry, or their irrigation schemes, to maintain good management practices (GMP) and to ensure a successful growing season over the summer.  

“There are two different types of irrigation consents we issue. Irrigation schemes typically hold a single consent covering all the irrigators that use the scheme, while individual consents cover a single farm not operating within a scheme command area,” Marco says.

“Both types of consents come with conditions and the responsibility to ensure that in exercising the consent, water is used responsibly.”

Good management practice

All farmers who irrigate must follow good management practice (GMP), which is a set of industry-agreed on-farm actions to improve water quality.

“GMP also helps farmers irrigate in a more sustainable and efficient way, identifies areas to improve their systems/practices, and can help in developing Farm Environment Plans,” Marco says.  

Good Management Practice in irrigation includes:

  • Checking soil temperatures and not irrigating where it is lower than 10 degrees Celsius.
  • Collecting  reliable information - soil moisture monitoring, past and forecast rainfall, and PET (potential evapotranspiration) forecasts and pasture/crop water needs.
  • Starting irrigating before crops get to stress points and never putting on so much that exceeds field capacity – aim for 90% of field capacity.
  • Checking if water restrictions apply, to avoid compliance issues.
  • Making sure the rate of application does not result in ponding or run-off, especially where effluent is applied. If it does, too much is being applied.
  • Grazing in advance of the irrigator to reduce soil compaction- stock hoofs compact wet soils. It is a good idea to keep a spade handy during the season to check on soil compaction.
  • Recording irrigation data and decisions for when the auditor arrives.
  • Adjusting application rate or turn off irrigator where rain is forecast.

Water metering

Last year, some changes were made to the New Zealand Water Meter Code of Practice, which sets the requirements and good industry practice for water metering/measurement devices.

“The key changes were to ensure these requirements aligned with the Government’s Resource Management Regulations, to require all water takes of five litres per second or more to record water use at 15-minute intervals, and provide this data to regional councils daily,” Marco says.

“This will be phased in between now and 3 September 2026, depending on the rate of water taken.”  

More information about what this means for farmers in Canterbury can be found at  

Technology maintenance

Technology is crucial to monitoring, understanding, and improving the way we irrigate.

“Keeping your technology up to date is key to running a smooth irrigation operation,” Marco says.

Here are some questions to ask yourself that can help you ensure your irrigation system is running optimally:

  • How uniform is your water application? Use a bucket test to check rate of application and distribution uniformity.
  • Do your water meter, pivot control and bucket test all agree on application rate?
  • How effective is your rate of application – is it infiltrating into the soil, ponding, or running off?
  • Are you able to control your system so that you do not put on more water than the soil can hold?  This is more challenging for K-lines and guns.

Asking for help

Marco notes that there’s always help available if farmers need advice or assistance.

“If you need help managing your irrigation, you can get in touch with your local Land Management Advisor by calling Environment Canterbury Customer Services on 0800 324 636 or contact Irrigation NZ,” he says.  

Find out more