It’s been an early start to the irrigation season, but as I sit here writing this article over 20 mm has now fallen meaning irrigation should not need to start again until early October. This season’s predictions are for a strong El Nino weather pattern, which means careful management of water allocations will be required. Taking account of the weather forecast, specifically rainfall and ET in the spring and autumn, is important for a productive irrigation season.
Over the last couple of days, I’ve seen irrigators going when perhaps they should not. Over 20 mm of rainfall and ET dropping to under 2mm/day has been forecast for the last 3-days. The weather has been unseasonably warm to date meaning irrigation has been justified (ET has averaged 3.5mm/ day and there’s been no rain). However, once the 3-day weather forecast is predicting significant rain and low temperatures, at this time of year we should be switching off, seeing what happens, and then catching up as required. This approach will save water allocations for the much drier times ahead.
Given 2023-24 is predicted to be a dry one, our suggestion is all irrigators need to have a close focus on their water meter data this season. In part this is to ensure allocations are not exceeded and compliance issues avoided, but as important is an accurate record of how much water is required in a dry season.
We’ve recently dealt with a couple of water take consent renewals where there has been difficulty retaining their full allocation. One involved an inaccurate water meter, and the other a poorly maintained telemetry system with gaps in the data record.
Environment Canterbury now takes account of historic water use when renewing consent allocation volumes. If your actual use is less than that allocated, then allocation volumes are being reduced accordingly. This is understandable because many zones are currently over allocated. When water use data is inaccurate this can jeopardise the viability of the farming business, or lead to a very expensive consent renewal process.
Checking the water meter and telemetry system is working is key. At the very least a back of the envelope calculation comparing expected flow rate with that being recorded should be undertaken. Better still is having the water meter and telemetry system independently verified. Quality water use data will ensure you are well set up for your future consent renewal.
Primary Insight are specialists in irrigation and water measurement. If you want to put in place reliable and accurate soil moisture monitoring on you farm, need support with trouble shooting an existing installation or would like to verify your water meter is reading correctly, we are here to help.
Alternatively, join us at one of our free irrigation workshops in October and November. Check out the event listings on our website for more information on dates and locations www.primaryinsight.co.nz. You’ll also get a certificate of attendance that satisfies your Farm Environment Plan irrigation training requirements.