Irrigation is widely accused of being a wasteful, low-value use of water. There is widespread confusion in the literature about what constitutes ‘‘water use’’ or what is “Water Use Efficiency”. The distinction between diversion and consumption of water is often overlooked. Water Use Efficiency, in the context of irrigation, is frequently interchanged with irrigation efficiency, or is often misquoted. The water balance approach, within defined boundaries, or across different levels of irrigation systems is crucial to assess performance of the systems within the Water Management Area. The fraction of the water abstracted from the source that can be utilised by the plant, can be called the beneficial water use component and optimised irrigation water supply is therefore aimed at maximising this component. “Measure; assess; evaluate; improve”, promotes an investigative water balance approach to improve water use efficiency.
ICID, under its policy to extend its knowledge dissemination wider, is initiating Webinar Services for its members in particular and wider irrigation and drainage community in general. This is the First Webinar being given under “ICID Webinar Services”, to bring a common understanding on the term “Water Use Efficiency” among the water policy makers, irrigation managers and wider water research community.
Er. Felix Reinders, a Professional Engineer, registered with the Engineering Council of South Africa, will be delivering the webinar. With vast experience in Irrigation and Drainage Engineering at the Agricultural Research Council’s Institute for Agricultural Engineering, Mr Felix plays a pivotal role especially in the co-ordination of irrigation engineering research, development, testing, design and training, and mentoring.
With his experience in the irrigation field and as former Chairperson of the South African National Committee on Irrigation and Drainage, he will present the South African experiences on the subject. At present, he serves on several International Committees and is Honorary Vice President of ICID and the force behind the Working Group for On-Farm Irrigation Systems. He is also the past President of the South African Institute of Agricultural Engineers and the South African Irrigation Institute
Dr. Chris Perry worked for the World Bank on irrigation and water resources projects for more than 20 years; and was subsequently head of research at the International Water Management Institute (IWMI). After retiring, has worked as a consultant for bilateral, multilateral donors, and was Editor in Chief of Agricultural Water Management Journal for five years.
Extract from the Introductory Speech
It is a privilege to introduce this discussion, and ICID should be congratulated on this initiative in starting this very wide conversation. We look forward to your comments and contributions later—these are important and complicated issues!
I am sure all of those participating today share a common interest in how we can move towards more sustainable water use, especially in areas where aquifers are already falling, rivers are drying and polluted, yet still demand for irrigation and other water services are expanding. No doubt we all have unique experiences to bring to the discussion, because almost every “water” situation has its own special features.
But one thing we all face: in future, we shall have to manage water resources better and more productively. And “we” includes farmers, engineers, administrators and politicians—not to mention academics, researchers and financing agencies. Much has been written and said on the topic in international conferences, papers and reports: lots of words, but little basic consensus about what actually needs to be done. Felix’s contribution will clarify at a very practical level what is happening in South Africa—but first a few words of background.
The most important change in the context of water resources management over the last 50 years or so has been the emergence of competition for water at basin scale: what we divert from a river or pump from an aquifer in one location has implications for other users and other sectors. This new reality means that the perfectly legitimate objectives of local water managers (individual farmers, projects managers, water supply utilities, etc) to better serve their local needs will have implications for other users. This in turn means that we need a common terminology for describing the impact of our interventions—terms like “water use”, “efficiency”, and “losses” have quite different meanings, for example to a farmer and a water supply utility. Indeed the meanings may even change between seasons if “inefficiencies” in irrigation during the monsoon are “recharge” for use in the dry season.
We need terminology that is clear for all users in all sectors, so that the analysis of an intervention in one location by one sector is useful and informative to another users at another location. That was what prompted the discussion (now some ten years ago) among the ICID community to reach a consensus on how to at least improve our analysis of these issues. As I think Felix’s presentation will demonstrate, we discover new insights when we apply this approach, we understand things better, and we make better decisions as a result.
Thank you for joining, now over to Felix.
ICID Webinar Schedule (Tentative)
3.Practical Benchmarking for Improving Performance of Irrigation and Drainage Schemes