Believe it or not winter can be the best time for testing irrigation equipment (obviously providing you have a water supply) as the weather is often at its most settled – fine days with no wind! There are different levels of testing being offered by the irrigation industry and you need to know what you are signing up for is the service you actually need. Given this we thought it would be useful to outline the various types of irrigation system performance assessments, the purpose and limitations of each alongside key considerations when engaging someone to assess your irrigation system.
There are three types of irrigation system assessments:
- An Annual Check involves pre and post start-up mechanical, pressure and flow checks to ensure your irrigation system is operating correctly. It is also prudent to periodically undertake these during the irrigation season, particularly for older equipment.
- A Bucket Test is an indicative check of the depth and evenness (uniformity) of the irrigation being applied. As no pressure or flow measurements are taken and a limited number of data points are sampled it is difficult to trouble-shoot any issues found. If you have a poor bucket test result, you should undertake a Full Performance Assessment to identify any issues prior to haranguing your service company as this will avoid unnecessary angst.
- Full Performance Assessments are the only way to assess an irrigation system with confidence. They are highly recommended if you are observing issues with crop production, energy or water consumption, but should also be undertaken at regular intervals throughout an irrigation systems life (we suggest a maximum of every 5 years). They involve buckets being placed at spacings that allow you to pinpoint individual sprinkler or regulator issues (typically 5m is required for this), alongside measurements of pressure and flow. Full Performance Assessments are the only effective means of systematically trouble-shooting irrigation system issues.
When engaging someone to undertake an assessment of an irrigation system you should ask them the following questions:
- What experience do they have, and if they hold the performance assessment qualification?
- What methodology do they use and how do they calculate the results? Specifically, for centre-pivots is the uniformity calculation weighted – does it recognise that more area is irrigated the further you move from the centre and weight accordingly – as this can impact results?
- Do they provide you with solutions to any problems found or do they just leave you with a list of issues?
- Ask to see a sample report as this will provide you the best indication of the service you are being provided with.
- Finally ask about the cost.
At Water Strategies, we only undertake Full Performance Assessments (Irrigation WOF). It is our opinion that irrigators are better offer investing in quality assessments of their irrigation equipment on a periodic basis (3-5 years) rather than ticking an annual compliance box. Given the considerable investment irrigators make in their irrigation systems the purpose of testing needs to focus upon maintaining production potential whilst optimising operational costs.