Management evaluation of Water Users Associations using benchmarking techniques

The development of different tools to evaluate the performance of Water Users Associations (WUAs) is an important practice for improving water and energy management, together with other production costs. One of these tools is the Benchmarking technique, which is based on the comparison between different WUAs to determine the best practices in each of them.In this paper, a Benchmarking process is applied to seven WUAs located in Castilla-La Mancha (Spain) during three irrigation seasons (2006–2008). The performance indicators developed by the International Programme for Technology and Research in Irrigation and Drainage (IPTRID) are used, while new indicators dealing with production and energy are proposed. The goals of this paper are to group WUAs with the same characteristics, using performance and energy indicators, and to reduce the set of indicators using statistical methods. The most important indicators, easy to obtain and yielding result in maximum information are retained for further use.Three proposals reducing the initial number of indicators were proposed, with an aim of being useful for future applications based on characterizing WUAs. Indicators results highlighted that irrigable areas can be grouped based on the application of drip irrigation systems and those with sprinkler irrigation systems. When using groundwater resources, no significant differences were observed for energy consumption between these irrigation systems. This can be explained by the indicator energy load index (ICE, m), which had similar values in all WUAs analyzed. According to annual irrigation water supply per unit irrigated area (VTSr, m3 ha−1), the highest values (between 5200 m3 ha−1 and 6800 m3 ha−1) were obtained in WUAs with sprinkler irrigation systems, which contained crops characterized by high water requirements, compared to the VTSr (less than 1800 m3 ha−1) of WUAs with drip irrigation systems, with crops that required less volume of irrigation water. Regarding production efficiency indicators, in drip irrigation systems the high presence of vineyards, almond and olive trees, crops with low water requirements, explained high values of gross margin per unit irrigation delivery (MBVs, € m−3)(close to 0.82 € m−3) in comparison with sprinkler irrigation systems (close to 0.36 € m−3).

Research highlights▶ The application of Benchmarking techniques based on indicators was a useful way to characterize WUAs and to analyze differences between them due to different crop systems, hydraulic design, irrigation systems, or management strategies. ▶ The combined application of multivariate techniques such as Principal Components Analysis (PCA) and Cluster Analysis (CA) for grouping WUAs and performance indicators has proven to be a useful methodology to discern which indicators have a higher contribution in characterizing WUAs. ▶ Cluster Analysis applied to WUAs showed a notable difference between irrigable areas with sprinkler irrigation systems and with drip irrigation systems. The similarities between areas irrigated with sprinkler irrigation systems were higher than between WUAs with drip irrigation systems. Slight differences between irrigation networks operated on demand and those operating under a rotational schedule were found. ▶ In sprinkler irrigation systems, energy costs represented 60% to 78% of the total management, operation and maintenance cost (CMS, €), while in drip irrigation systems energy represented about 45% of the total costs. ▶ In drip irrigation systems, the high presence of vineyards, almond and olive trees, which have low water requirements, can explain high values of gross margin per unit irrigation delivery (MBVs, € m−3)(close to 0.82 € m−3), in comparison with sprinkler irrigation systems (close to 0.36 € m−3).