Gediz Basin irrigation system 

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... Turkey, irrigation is the most important element in agricultural development strategy. This importance is further increased by the dependence of the country’s industry on agriculture. As in the whole of the Middle East, water sources in Turkey are increas- ingly insufficient because of the rising population. Not only industrialization but also global warming and the lack of homogeneity in the distribution of water sources within the coun- try further increase the severity of this problem. In Turkey, 60% ͑ 5.1 ϫ 10 6 ha ͒ of agricultural land which can technically and eco- nomically be irrigated is actually under irrigation and about 70% of Turkey’s water potential is put to agricultural use ͓ Devlet Su İş leri ͑ DSI ͒ 2008; Çakmak and ve Aküzüm 2006 ͔ . Performance assessment of irrigation and drainage is the sys- tematic observation, documentation, and interpretation of the management of an irrigation and drainage system, with the objec- tive of ensuring that the input of resources, operational schedules, intended outputs, and required actions proceed as planned ͑ Bos et al. 2005 ͒ . The operation and maintenance of a significant proportion of Turkey’s irrigation systems was handed over in the short space of just a few years from the government organization the General Directorate of the State Hydraulic Works ͑ Devlet Su İş leri ͒ , which had been responsible for the planning, construction, and maintenance of the country’s irrigation systems, to the Water Users’ Associations ͑ WUAs ͒ in an accelerated program in the 1990s. By 2007, a total of 2 ϫ 10 6 ha of irrigated land had been handed over ͓ Devlet Su İş leri ͑ DSI ͒ 2008 ͔ . It is of great importance to evaluate the performance of the WUAs and their current level of success with regard to assessing whether the transfer reached its objec- tives ͑ Nalbantoglu and ve Çakmak 2007 ͒ . Work on assessing irrigation system performance has gained importance in parallel with this transfer operation, and many studies have been carried out on this topic ͑ Beyribey et al. 1995; Beyribey, 1997; Çakmak 1997; Geçgel et al. 2000; Svendsen and Murray-Rust 2001; Ünal et al. 2004a,b; Merdun 2004; Kıymaz 2006; Akkuzu et al. 2007a ͒ . A large proportion of these studies were carried out in the Gediz Basin in the west of Turkey, where the first transfers took place. Svendsen and Murray-Rust ͑ 2001 ͒ evaluated the effectiveness of the Turkish program of irrigation management transfer from a national perspective. They assessed the impacts of the transfer program, including changes in staffing levels, operational costs, service fee levels, and cost recovery from farmers. They reported that 79% of water fees were collected in WUAs and only 43% in DSI-managed schemes. They also indicated that a regular moni- toring program was needed for irrigation systems transferred from the DSI. Ünal et al. ͑ 2004a ͒ examined the water delivery performance of the Menemen Left Bank Irrigation System, which is the lower section of the Lower Gediz irrigation system in the west of Tur- key. In their study, performance was evaluated at tertiary canal level using the indicators of adequacy, efficiency, dependability, and equity. Water delivery performance to the tertiaries rated worse for adequacy, dependability, and equity than for efficiency. The analysis results of the spatial and temporal dimensions of these indicators show that factors causing this problem derive in part from physical structure and in part from management. Work by Akkuzu et al. ͑ 2007a,b ͒ at WUA level in the same basin showed similar results. Kıymaz ͑ 2006 ͒ stated that the operation of irrigation schemes transferred to WUAs in the Gediz Basin reduced operational ex- penditures and increased collection of water fees. The numbers of operation and maintenance personnel in İ zmir and Manisa DS İ were decreased by 57 and 65%, respectively. This reduced the financial burden of the DSI; However, the number of WUA personnel increased. According to the results of the study, the WUAs were not capable of operating and maintaining the irrigation schemes for various reasons, including insufficiency of machinery and lack of technical personnel. A study by Akkuzu et al. ͑ 2008 ͒ on the Menemen irrigation system in the Gediz Basin found that canal leakage was high because of such problems as the age of the canals and insufficiency of repair and maintenance work. In another study of the same system, A ş ık et al. ͑ 2004 ͒ found that a very low proportion of the budget was spent on maintenance and repair. Most of the studies carried out are ones which deal with operation, maintenance, and finance and assess the current situation of transferred irrigation system to WUAs. The effect of the change in management on the use of land and water resources has not been sufficiently addressed, and the question of how irrigated agriculture performed with limited water and land resources before and after management transfer has not been satisfactorily answered. However, the main aim and focus of this study is to draw attention to the effects of the management transfer on water and land productivity and water supply in the Gediz Basin, which has great agricultural potential and which was one of the first to be transferred. The Gediz Basin in western Turkey has long been an important center for agricultural production. It has a total area of some 17, 000 km 2 . During the winter months precipitation exceeds 700 mm, falling as snow at elevations above 1,000 m. Total irrigation command area of the Lower Gediz Irrigation Scheme is 110,000 ha. The Gediz basin is dominated by cotton and grapes and is one of the largest producers of raisins in the world. Other commercial crops such as fruits and vegetables are exported throughout Turkey as well as directly to the European Union ͓ Murray-Rust et al. 2003; Devlet Su İş leri ͑ DSI ͒ 2000 ͔ . Operation of the four irrigation systems of the Lower Gediz Basin ͑ Adala, Turgutlu, Manisa, and Menemen ͒ was managed by the DSI until 1995, after which it was handed over to ten WUAs which were formed. The net irrigated areas and water sources of these associations are given in Table 1 ͓ Devlet Su İş leri ͑ DSI ͒ 2000 ͔ . Water in the system is supplied via the Demirköprü Dam to the Adala, Ahmetli, and Emiralem Regulators in that order from the source and to six main canals connected to them. In months when irrigation in the system is intense, water is supplied from the extra sources of the Gölmarmara Lake to Ahmetli and the Menemen Regulator ͑ Fig. 1 ͒ . The DSI is responsible for control of the dam and the regula- tors and for delivery of water to the associations. The WUAs have full responsibility for operating and maintaining all secondary and tertiary canals, they devise and develop water distribution policies among water users, and they are fully responsible for implement- ing the water allocation and distribution plan ͑ Akkuzu et al. 2007a,b ͒ . Payment for irrigation water is calculated according to land area. Before that start of the irrigation season, WUAs prepare a budget estimating operation maintenance and other costs and announce the charge for irrigation water per unit of land area in accordance with this budget. For more details on the Gediz Basin irrigation system, see Svendsen and Nott ͑ 1999 ͒ and Svendsen and Murray-Rust ͑ 2001 ͒ . In this study, six WUAs representing the head, middle, and lower end of the system were selected from among the 10 WUAs of the Lower Gediz Basin, namely, Salihli Right Bank and Salihli Left Bank from the upper valley, Sarikiz, Mesir, and Turgutlu from the main valley, and Menemen Left Bank from the delta. The land irrigated by the six WUAs selected comprises about 78% of the Gediz irrigation system. Data for the years 1985–2005 on irrigation ratios, crop planting areas, and seasonal delivery of irrigation water and yield of crops and local prices are taken from DSI reports ͓ Devlet Su İş leri ͑ DSI ͒ 1985–2005a,b ͔ . This study compares the performance of five irrigation associations in the Lower Gediz Basin in the periods before ͑ 1985– 1988 ͒ , during ͑ 1993–1996 ͒ , and after ͑ 2002–2005 ͒ the transfer. Six of the nine comparative ͑ external ͒ performance indicators were used for this purpose. These external indicators have been widely field tested and published as the set of comparative indicators in International Water Management Institute ͑ IWMI ͒ . These indicators are a tool for comparison between countries and regions, different infrastructures, management types, and environ- ments and for assessments over time of the trend in performance of a project ͑ Sakthivadivel et al. 1999 ͒ . The first four of them relate annual output to land and water and provide the basis for comparison of irrigated agriculture. The other two relate to water supply. These indicators are calculated as follows ͑ Molden et al. 1998 ͒ ...