Irrigation Evaluation - Code of Practice & Qualification

To provide the production (quality and yield) benefits farmers want from their irrigation investrment and to minimise its environmental impact, irrigation needs to be efficient and effective. This requires good system design, installation, operation and maintenance.

From an operation and maintenance viewpoint irrigators need to know how much water their systems are applying and how well their system is performing........ and they need to know why it is not working if they are to fix it!

How to evaluate?

Each type of irrigation system (pivot, traveller, long lateral, drip, microsprinkler.....) functions differently. Each is affected by different factors and so different methods of assessment are needed. Fortunately, many performance indicators are common, so although we may need to measure systems in different ways, the performance of irrigation systems is easily comparable.

An Irrigation Evaluation focuses on a set of key checks -

• Is the system applyng the expected depth of water?
• Is it applying the water evenly (uniformly)?
• Is it applying the water at a rate that the soil can accept?
• Is the energy use reasonable?
• What is causing any non-performance? 

To formalise the evaluation process, the Code of Practice for Irrigation Evaluation was developed. The Code sets out protocols and procedures for evaluating the common types of irrigation systems. It is supported by a software package to help simplify and ensure consistent data analysis and is backed by a New Zealand National Certificate in Irrigation Evaluation.

IrrigationNZ recommends that irrigators should undertake a simple performance check of their irrigation system on an annual basis and there are a number of tools available to do this including Irrig8Quick and DIY Spray Irrigation Performance Evaluation.

However, if you know you have performance problems with your irrigation system or you have recently undertaken a 'simple performance check' and things are not looking too hot, there are a number of Qualified Irrigation Evaluators that you can engage to help you get back on track.