ZEF Work Papers for Sustainable Development in Central Asia No. 12

Zentrum für Entwicklungsforschung Center for Development Research ZEF Bonn

Economic and Ecological Restructuring of Land and Water Use in Uzbekistan/Khorezm: A Pilot Program in Development Research

ZEF Work Papers for Sustainable Development in Central Asia

No. 12

Irrigation and Drainage Systems in Khorezm, Uzbekistan

Usman Khalid Awan, Bernhard Tischbein, Christopher Conrad, Murod Sultanov, John P. A. Lamers

Urgench, December 2011

ZEF-Uzbekistan working papers contain preliminary material and research results from the ZEF/BMBF/UNESCO-Project on Economic and Ecological Restructuring of Land- and Water Use in the Region Khorezm (Uzbekistan). They are circulated prior to a peer review process to stimulate debate and to disseminate information as quickly as possible. Some of the papers in this series will be reviews and eventually be published in some other form, and their content may also be revised. The sole responsibility for the contents rests with the authors.

Project internet site: http://www.khorezm.uni-bonn.de/

Table of content

Preface ...... 6

1 Introduction ...... 7

1.1 History of irrigation in Khorezm ...... 8

1.2 Evolution of drainage system in the region ...... 12

1.3 Water distribution structure ...... 14

2 Water Consumers Associations (WCAs) ...... 17

3 Irrigation network and irrigation network density in the region: Technical parameters ...... 18

3.1 Primary canals ...... 19

3.2 Secondary canals ...... 20

3.3 Tertiary canals ...... 21

4 Design discharge of canals in different irrigation systems ...... 22

4.1 Overview of the irrigation system ...... 23

4.2 Toshsoka irrigation system ...... 24

4.3 Palvon- Gazovot irrigation system ...... 27

4.4 Shovot-Kulovot irrigation system ...... 31

4.5 Karamazi-Kilichbay irrigation system ...... 37

5 Irrigation network efficiency of some of the main canals ...... 39

6 Lift irrigation schemes in the region ...... 41

7 Drainage network in the Khorezm oasis ...... 41

7.1 Collectors ...... 42

7.2 Drains ...... 42

8 Summary and Conclusions ...... 43

9 References ...... 44

10 Appendix ...... 45

List of Tables

Table 1 Change in size of irrigated lands in the Khorezm oasis over time (1000’ ha) ...... 9 Table 2 Changes in silt content of Amudarya water in 1985 along with the construction of the Tuyamuyun water reservoir (g m-3) ...... 11 Table 3 Length of the collector drainage system (CDS) of the Khorezm oasis and its estimated network density. The total area taken into consideration is 455,200 hectares (Hydromelioration Expedition, OGME)...... 14 Table 4 MK main canal of Toshsoka irrigation system ...... 24 Table 5 R-5 main canal of the Toshsoka irrigation system ...... 25 Table 6 Pitnakarna main canal of the Toshsoka irrigation system ...... 25 Table 7 R. Sabirov main canal of the Toshsoka irrigation system ...... 26 Table 8 R-8 main canal of Toshsoka irrigation system ...... 27 Table 9 P-9a main canal of Palvon Gazovot irrigation system ...... 27 Table 10 P-9 main canal of Polvon-Gazovot irrigation system ...... 28 Table 11 Nukusa main canal of Polvon-Gazovot irrigation system ...... 28 Table 12 Nukus main canal of Polvon-Gazovot irrigation system ...... 29 Table 13 Keneges main canal of Polvon-Gazovot irrigation system ...... 30 Table 14 Zey-Yop main canal of Polvon-Gazovot irrigation system ...... 30 Table 15 Tugay-Yop main canal of Polvon-Gazovot irrigation system ...... 31 Table 16 R-7 main canal of Shovot-Kulovot irrigation system ...... 31 Table 17 Urganch-arna main canal of Shovot-Kulovot irrigation system ...... 32 Table 18 Daryolik-arna main canal of Shovot-Kulovot Irrigation System ...... 33 Table 19 Kulovot main canal of Shovot-Kulovot Irrigation System ...... 34 Table 20 Beg Yop main canal of Shovot-Kulovot Irrigation System ...... 34 Table 21 "Davdon Yop" main canal of Shovot-Kulovot Irrigation System ...... 35 Table 22 Udachi Yop main canal of Shovot-Kulovot Irrigation System ...... 35 Table 23 Shovot-Kongli main canal of Shovot-Kulovot Irrigation System ...... 36 Table 24 Shovot-Begovot main canal of Shovot-Kulovot Irrigation System ...... 36 Table 25 KDOK main canal of Shovot-Kulovot Irrigation System ...... 37 Table 26 Yangibazar main canal of Karamazi-Kilichbay Irrigation System ...... 37 Table 27 Alga main canal of Karamazi-Kilichbay Irrigation System ...... 38 Table 28 Kengesbaev main canal of Karamazi-Kilichbay Irrigation System ...... 38 Table 29 Gurlan vetka main canal of Karamazi-Kilichbay Irrigation System ...... 38 Table 30 Toksan arna main canal of Karamazi-Kilichbay Irrigation System ...... 39 Table 31 Karakuz main canal of Karamazi-Kilichbay Irrigation System ...... 39 Table 32 Irrigation network efficiency of selected main canals ...... 40 Table 33 Lift irrigation schemes in the Khorezm region of Uzbekistan ...... 41

List of Figures

Figure 1 Overview of the irrigation and drainage system (source: Conrad, 2006) ...... 7 Figure 2 Average monthly values of reference evapotranspiration and precipitation (means from 1985-2007) ...... 8 Figure 3 The Tuyamuyun reservoir complex (Landsat satellite image, August 2010, false color composite, source: USGS, University of Wuerzburg ...... 11 Figure 4 Water distribution structure in the Khorezm oasis of Uzbekistan ...... 15 Figure 5 Delineation of the five irrigation management systems in the Khorezm oasis of Uzbekistan ...... 16 Figure 6 Organizational structure of the Lower Amudarya River Irrigation System Basins Management ...... 16 Figure 7 Average canal distance from water intake point to the water consumer associations (WCAs) located in Khorezm...... 18 Figure 8 Map of the irrigation system in Khorezm region of Uzbekistan...... 19 Figure 9 Map of the primary irrigation canals in the Khorezm region of Uzbekistan ...... 20 Figure 10 Map of the secondary irrigation canals in the Khorezm region of Uzbekistan ...... 21 Figure 11 Map of the tertiary irrigation canals in the Khorezm region of Uzbekistan ...... 22 Figure 12 Map of the main collectors in the Khorezm oasis of Uzbekistan ...... 42 Figure 13 Map of the drains in the Khorezm region of Uzbekistan ...... 43

Glossary

Name Description Unit

Collectors Ditches which take the water directly from the km drains and convey this drainage water out of the system (or to main collectors) Design discharge Design of the canal to carry required cubic meters of m3s-1 water in one second Drainage density The length of drains (m) per unit area (hectare of m ha-1 irrigated land) Drains Ditches taking surface runoff from the irrigated km fields, eventual overflow from the irrigation system and groundwater flow to control groundwater level; drains convey water to the collectors Irrigation network The length of canals (m) per unit area (hectare of m ha-1 density irrigated land) Irrigation network Measure of the losses from the irrigation channels % efficiency Lift irrigation Pumping stations which pump the water from the - schemes primary canals into the distributory canals Precipitation Any product of the condensation of atmospheric mm water vapor that falls under gravity (rainfall, snow) Primary canals Canals which do not irrigate directly fields but km supply water to the next hierarchy level of canals Reference Evapotranspiration from a reference crop i.e., from a mm evapotranspiration hypothetical crop with an assumed height of 0.12 m, with a surface resistance of 70 s m-1 and an albedo of 0.23 (Allen et al., 1998) Secondary canals Canals that are fed by water from primary canals km Tertiary canals Canals fed with water from the secondary canals and km convey it to the farm boundaries Yaps Uzbek word for canals -

PREFACE Irrigated agriculture is the lifeline of Uzbekistan’s economy as is the case in Khorezm, located in the Northwest of the country. The agricultural sector contributes to about 33 % of the country’s gross domestic product (GDP) and employs 60 % of its labor force (Djalalov, 2001). Due to the arid climate, agriculture consumes 95 % of Khorezm’s total water use of 5 km3 (Dukhovny and Sokolov, 2001). These amounts of water originate from the Amudarya River, the only source of (irrigation) water supply. An extensive irrigation is operated to distribute freshwater and the drainage infrastructure to manage groundwater table and control soil salinity for ensuring long-term crop production. Water availability from the Amudarya River is varying notably between the years. Statistical records between 1990 and 2011 show that the region frequently experiences insufficient water supply, as evidenced in the period 1999-2001 or in 2008 particularly so in the downstream and middle-stream reaches of the irrigation network. This document reports on the irrigation and drainage systems in the Khorezm oasis of Uzbekistan, geographically located at the lower reach of the Amudarya River. Addressed are in particular the design parameters (discharge; layout) of the irrigation and drainage systems including irrigation network efficiencies. Also the history and development of the irrigation and drainage systems are described. Moreover, this manuscript summarizes the evolution of the drainage systems which to a large extent was needed to react to the mounting problems of soil salinisation. Although funds have been made available from the national budget, additional resources are needed for especially continuous and adequate maintenance.

1 INTRODUCTION Continental arid climate conditions are typical for the middle and lower part of the Aral Sea Basin, where also the Khorezm region is located. The summers are extremely hot and potential evapotranspiration (ETo, see Annexes 1 and 2) exceeds precipitation by far (Conrad et al. 2012). Hence, to fulfill crop water demand (as indicated by ETo), irrigation becomes necessary. In Khorezm, irrigation is facilitated by water withdrawals from the Amudarya River only, which is channeled through an extensive irrigation system. As in all irrigation systems located in flat terrain such as is the case in the Khorezm region, a second infrastructural network, the drainage system became necessary to manage groundwater table and control soil salinity. The major branches of the irrigation and drainage system are presented in Fig. 1.

Figure 1 Overview of the irrigation and drainage system (source: Conrad, 2006)

The long-term annual average reference evapotranspiration (ETo) and precipitation for the last 25 years in the Khorezm region are 1,338 and 94 mm, respectively (Fig. 2). The maximum ETo occurs during the months of June (221 mm) and July (215 mm) whereas average rainfall during June and July is 4 and 1 mm, respectively. The vegetation season for

7 cotton, the dominant crop in the region, is roughly from April to September. The long-term average ETo during this period is 1098 mm whereas rainfall is only 33 mm.

Figure 2 Average monthly values of reference evapotranspiration and precipitation (means from 1985-2007)

To enable agricultural production in the Khorezm region, the large gap between crop water demand (as indicated by ETo) and precipitation is bridged by irrigation. As a prerequisite, an extensive irrigation system was established in Khorezm (Fig. 1). Since an irrigation network alone is insufficient later also a drainage network was implemented to manage soil salinity in the long-term (Fig. 1). For an adequate management of the irrigation and drainage systems in Khorezm, planners and operators need to be aware of various characteristics such as the geometry, hydraulic capacity and efficiency of the irrigation and drainage network. This knowledge can also contribute to research and studies related to irrigation and drainage practices in the Khorezm region.

1.1 History of irrigation in Khorezm The principal source of all water resources in the Khorezm region is the Amudarya river, which flows along the eastern part of the region. Around 455,000 ha of Khorezms’ territory (total ca 670,000 ha) are located on the left bank of the Amudarya. The river is fed by the streams from snow and glacier melt on the mountainous region in the Pamir Knot at the eastern end of Afghanistan's Wakhan Corridor. More than about 25-30 thousand years ago, the Amudarya oriented east and ended in the Khorezm depressions (Nasonov, 2007).

First irrigation structures on Khorezms’ territory are backdated to 1,000 Before Christ (B.C.). During the reign of Abulgozikhan and his son Аnnushakhan, much attention was given to canal digging. In 1681, the Shohobot (present Shovot) canal and between the 17th and beginning of the 18th century, the Gozovot canal was constructed. Between the late 17th and early 19th centuries, many canals and farm channels have been built in addition (Jabbarov, 2005). Between 1939 and 1941, a halq hashar (Uzbek for voluntary social work) warranted the maintenance of small and major channels and the construction of new ones in the Khorezm oasis. As a result, canals such as Polvon, Gozovot, Honka-Arna, Shovot and Kichik- Buzsu, which take water directly from the river, were united in one system, called since then the Toshsaka system. Along with the Тоshsaka system, the Kilichniyozboy, Tuksan-Arna, Mangit-Arna but also other canals were repaired and rebuilt. Yet, only within the Toshsaka system, hydraulic structures were built at all intake points to control the water flow. In the other major and inter-farm canals, none of such structures are built yet. The length of the Toshsaka canal is 175 km and was and still is of great importance while supplying more than 50 other canals.

Table 1 Change in size of irrigated lands in the Khorezm oasis over time (1000’ ha) Total area (left 1940 1960 1980 1990 2000 2002 bank) 455.2 136.97 146.3 171.9 259.6 254.2 260.9 % 30.1 32.1 37.8 57.0 55.8 57.3 Source: GIS lab of the ZEF/UNESCO project in Urgench

The Tuyamuyun reservoir complex and its role for the irrigation system of Khorezm Prior to the construction of the Tuyamuyun reservoir, the Amudarya River carried high quantities of water every year which resulted in flooding (Uzbek: Deygish) of the flanking lands when the river embarked outside its bank. These frequent floods explain in part that most water constructions regulating the water inflow through canals into the irrigation system of Khorezm has been constructed at several kilometers distance from the river bed. The Tuyamuyun reservoir complex (Fig. 3) is built in the southeast of the Khorezm oasis. In the vicinity of Pitnak, the Amudarya flows through hard rocks and forms the pitnak tirsak (elbow). The construction for regulating the water flow was built in the narrowest part of the river named Tuyamuyun. The Tuyamuyun reservoir is with an area of 650 km2 one of the largest in Central Asia. Its construction started in 1969 and the reservoir became operational in 1983.The hydro-engineering complex consists in fact out of four separated 9 reservoirs: the Channel Reservoir, Kaparas, Sultansandjar, and Koshbulak (Fig. 3). The Tuyamuyun water reservoir includes a dam of 181 m length, with a height of 28 m and a hydroelectric power station. The reservoirs’ average depth is 20 m but at deepest places it may reach 40 m and more. The initial (in 1983) storage capacity was 7.8 km3. Siltation processes reduced however the storage capacity by 1 km3 during the period 1983-2001 (Froebrich et al. 2007). The reservoir can supply up to 5 km3 to Uzbekistan and Turkmenistan. The capacity of the hydroelectric power station associated with the Tuyamuyun reservoir complex is 150,000 kilowatt per second and includes 6 units. The hydro-junction dam consists of 12 inlet gates, which can let in 54 m3 water per second. The water distribution unit on the left bank of the water reservoir has the hydraulic capacity to carry out 500 m3 per second; the one on the right bank to carry out 90 m3 per second. After the construction of the Tuyamuyun reservoir complex, natural discharge of the Amudarya could be regulated to a large extent for the entire Amudarya delta. But although this reservoir now cushions floods, in extreme years such as 2004, floods caused by melts of enormous snow volumes had a hazardous impact on agricultural production along parts of the natural riverbed, downstream the dam. A major part of the irrigation system of Khorzm (Toshsoka system) is directly fed from the Tuyamuyun reservoir complex, rather than directly from the Amudarya river. In fact, only a small part of the entire irrigated areas in Khorezm, which are part of the Pitnyak, Daryalik, and Klichbay systems and the areas fed by pumps installed at the river banks, receives its water directly from the river. Since however, these intake points are located downstream from the Tuyamuyun reservoir, they thus also depend on water releases from the Tuyamuyun back to the river. Since the river changes its beds regularly during the year, especially in drought periods, direct access to river water is and remains small and limited.

Figure 3 The Tuyamuyun reservoir complex (Landsat satellite image, August 2010, false color composite, source: USGS, University of Wuerzburg

Setting into operation the Tuyamuyun water reservoir reduced silt contents of the water applied for irrigation in the Khorezm oasis. According to studies conducted after the construction of Tuyamuyun reservoir, during the vegetation season, the silt content of the water flowing to the Khorezm oasis from the Amudarya had decreased drastically.

Table 2 Changes in silt content of Amudarya water in 1985 along with the construction of the Tuyamuyun water reservoir (g m-3) Measurement point for silt content March May June July August Up Dargan-Ata reservoir - 12800 1360 1910 890 Down the Tuyamuyun water reservoir 40 30 50 700 120 ПК 34 (Toshsaka canal) 80 60 150 740 240 Urgench (Shovot canal) 430 480 200 1250 320 Polvon Gozovot in the direction of 190 290 820 1400 340 Urgench city Source: Fayzullayev, 1985

1.2 Evolution of drainage system in the region At different periods in the history of the Khorezm oasis, the development of the collector and drainage system was deemed necessary due to shallow groundwater (GW) levels caused by the intensification of the irrigation system over time which initially occurred without the installation of a drainage network (Assche and Djanibekov, 2011). But despite the construction of a drainage network, land degradation caused by soil salinisation continued as evidenced in the increase in soil salinity and a rise of the groundwater tables to unallowable depths (Ibrahimov et al., 2007). This has substantially been caused by the dysfunctional on- farm and inter-farm drainage system and severe outlet problems. The development of the collector and drainage system (CDS) in the Khorezm oasis can be described in three stages of which the first stage lasted for many centuries. Stage 1: For many centuries and until the middle of the last century, soil salinity control of the irrigated lands in the Khorezm oasis was based on a transition of the agricultural system. This was possible due to the low intensity of land use and slow movement of salts towards the non-irrigated sites (“dry drainage”). In addition, the irrigation system remained unused during the non-vegetation period (roughly November-February), whilst the irrigated sites were too small and well leveled, and the water level of the canals was lower than the ground surface. Water for irrigation was supplied through a system of so-called chigirs, which carried out a tight control of irrigation norms. The measures combined limited the recharge of the groundwater resulting in comparatively deep groundwater tables. In addition, also the large-scale cultivation of deep rooting crops such as Lucerne contributed to lowering groundwater levels in the root-inhabited layer. Deepened canals played the role of collectors, and effluents from main channels were diverted into adjacent lakes. Therefore, a more developed drainage system was initially not necessary and an organized discharge of drain waters and salt removal out of the Khorezm oasis was not needed during many centuries. The constructed inter-farm and inter-rayon collectors (see sections 3.1 and 3.2) were sufficient to bring the drained water to the lakes and lowlands. Stage 2: The second stage (1950-1961) in the development of the drainage system was triggered by the increase in irrigated lands which was followed by an immigration of people that in turn rapidly increased natural population growth in the Khorezm oasis. Since the existing irrigation system during this second period restricted the intended expansion of new agriculture land, it was inevitable to introduce a separate irrigation system, which in turn necessitated the reconstruction of the main head works and main canals. As a result of this, the level of the water in the canals rose considerably. This increased first the volume of the

12 water supply for irrigation but also the share of the irrigation water losses recharging the groundwater. This in turn brought about a sharp increase in the groundwater table and in the worsening of the land melioration. Due to in particular the sequence of these events, the construction of a drainage system, with magisterial and inter-farming collectors, became necessary. However, a full-scale construction of the highly necessary drainage system required huge funds, resources and time, which were unaffordable at that time. Therefore, a simplified alternative was chosen. According to the primary scheme, firstly, farm collectors were constructed for the discharge of drain water caused by water intakes into peripheral lakes and low lands. It was assumed that the discharge of drainage water into lakes and lowlands would be compensated for by the evaporation from the newly established water surface. For that purpose, the Ozerko-Urovnitelniy (Lake-Leveling) collector was constructed as to connect the lakes in the lower lying areas close to the southern border of Khorezm between and near to the irrigated areas. Stage 3: In the third stage (1961 till now), the Daryalik, Daudan and Ozerniy collectors were constructed as to discharge drain and excessive water to the Sarikamish depression (now in Turkmenistan). It was planned that the depth of collectors would be 2.5- 3.0 m, but due to the sand layers at this depth, it was impossible to reach this objective throughout Khorezm. The depth of the collectors is only 1-1.5 m, in deep places it is 1.75 m.

Table 3 Length of the collector drainage system (CDS) of the Khorezm oasis and its estimated network density. The total area taken into consideration is 455,200 hectares (Hydromelioration Expedition, OGME). Irrigated Length of CDS (km) Network Network Year area, density of density of 1000‘ ha Total From that CDS referring CDS referring Interfarm Within to irrigated to total area farm area 1953 143.6 2500.0 1210.0 1290.0 17.40 5.5 1961 146.3 2610.4 1385.0 1225.4 17..84 5.74 1963 151.8 2774.1 1548.7 1225.4 18.27 6.10 1965 151.4 3227.2 1889.7 1337.6 21.32 7.09 1968 150.7 4269.0 2250.0 2019.0 28.33 9.37 1970 151.9 4571.8. 2342.2 2229.6 30.10 10.04 1971 157.9 4939.4 2454.9 2484.5 31.28 10.85 1975 168.1 5755.4 2505.6 3249.8 34.24 12.65 1980 191.8 6569.1 3097.2 3471.9 34.25 14.43 1982 199.44 6780.1 3137.8 3642.3 34.0 14.90 1984 217.61 7702.1 3329.7 4372.4 35.39 16.93 1985 223.8 7830.5 3355.1 4475.4 35.0 17.20 1986 237.4 8645.5 3388.2 5257.3 36.42 19.00 1987 250.2 8894.0 3383.0 5511.0 35.55 19.54 1988 256.33 9021.6 3372.1 4649.5* 35.2 19.83 1989 259.17 9139.5 3394.3 5745.2 35.26 20.08 1990 260.80 9628.9 3400.0 6228.9 36.92 21.16 Source: Fayzullayev, 1985. *The estimated density results do not always match and should therefore in some cases be taken with caution.

1.3 Water distribution structure The National Ministry of Agriculture and Water Management (MAWR) is responsible for the planning of water allocation in Uzbekistan and collaborates therefore intensively with the Interstate Commission for Water Coordination (ICWC). Transboundary water management between Central Asian (CA) countries and Afghanistan is the responsibility of the BVO (Basin Water Management Organization) ‘Amudarya’, which is the executive body of the ICWC. The Khorezm oasis and part of neighboring Karakalpakstan is served by the lower- Amudarya River Basin Management, which consists of five Irrigation System Management bodies (Fig. 4). The main task of the BUIS (Basin Management Department of Irrigation System) is allocating water to Irrigation Systems and Magisterial Canals (UISs); the UISs then delegate tasks to sub-UISs (Irrigation System Management Organization), which ultimately distributes water to Water Consumers Associations (WCA) based on properties of the different canal types (e.g. capacity, conveyance losses).

Figure 4 Water distribution structure in the Khorezm oasis of Uzbekistan

Ministry of Agriculture and Water Management

Basin Managements of Irrigation System

Irrigation Systems and Magisterial Canals

Primary Water User

Secondary Water Users (Farmers and Households)

Regional level water distribution in Khorezm oasis

Based upon the main canals and their arable area, the Khorezm oasis is divided into five irrigation systems i.e., Toshsoka, Polvon-Gozovot, Shovot-Kulovot, Koramazi-Kilichbay, and Mangit-Nazarhan (Fig. 5) systems, which in turn are managed through different subsections (Fig. 6).

Figure 5 Delineation of the five irrigation management systems in the Khorezm oasis of Uzbekistan

Figure 6 Organizational structure of the Lower Amudarya River Irrigation System Basins Management

The Lower Amudarya River (Irrigation System Basins Management)

Toshsoka Polvon- Shovot- Koramazi- Mangit- Hydro Melioration Gozovot Kulovot Kilichbay Nazarhan Expedition

Kizilkum Bogot Bogot Yangibazar Amudarya Pitnak Khanqa Khanqa Gurlan Khazarasp Yangiarik Urgench Bogot Urgench Yangibazar Yangiarik Khiva Koshkupir Khanqa Koshkupir Shavat

2 WATER CONSUMERS ASSOCIATIONS (WCAS) Since independence of Uzbekistan in 1991, the managerial infrastructure and management of land and water resources in Uzbekistan has been changed (Veldwisch, 2007), including the transformation of the former kolkhozes (collective farm enterprise) to new Water Consumers Associations (WCAs). The WCAs are not only responsible for the water distribution, but have also been mandated with other tasks. These included for example the redistribution of land to families, increasing wheat areas for food security, implementing a quota system for cotton and wheat, changing in agricultural subsidies, and the dismantling of large collective farms (Abdullaev et al., 2008). The water allocation in the region is demand-driven, since the total water withdrawals from the Amudarya River are based on the total water requirements of all WCAs. In this bottom-up water demand approach, the water users within WCAs are the starting- point. The adequacy, equity and reliability of water allocation and water distribution in all sub-units are always questionable despite the high annual withdrawals. One relevant piece of information indicating the potential water availability is the distance of the canal in a given WCA to the entrance point of the irrigation system it belongs to (Conrad 2006, Fig. 6). Estimates were completed for several configurations of the irrigation system and on a monthly basis during the vegetation season. Based on observations in 2004 and 2005, the findings showed a high redundancy between the years which necessitated a design configuration of the system. For each configuration the reticular distances between the intake nodes of the WCAs to the respective provision nodes from the river or Tujamujun reservoir were therefore calculated and averaged. For instance, the canal distance within the Daryalik system (see Fig. 7) and the connected WCAs is low, but only in July and August, so during two months of the year. The rest of the year (10 months) the same WCAs form one tail-end of the Toshsoka system. As a result, the Daryalik system, even though located in close neighborhood to the river, is in fact one distal part within the irrigation system.

Figure 7 Average canal distance from water intake point to the water consumer associations (WCAs) located in Khorezm.

3 IRRIGATION NETWORK AND IRRIGATION NETWORK DENSITY IN THE REGION: TECHNICAL PARAMETERS The Amudarya River is, as previously mentioned, the sole source of (irrigation) water in the region. Water withdrawal from the river is conveyed to the agricultural fields through a network of irrigation channels consisting out of three types of hierarchical canals; magistral, inter-farm and on-farm canals1. The total length of all canals is 16,377 km (Fig. 7). The irrigation network density (the length of canal per unit hectare of irrigated land) of the Khorezm region amounts to 59 m ha-1 assuming that a total area of 276,600 ha can be irrigated which is not always the case.

1 Based upon the hierarchy of the canals, the local classification is magistral, inter-farm and on-farm canals. In this document, we used further the general terms i.e., primary, secondary and tertiary canals. Primary canals distribute water from irrigation source to the secondary canals which then supply water to the tertiary canals. 18

Figure 8 Map of the irrigation system in Khorezm region of Uzbekistan.

Source: GIS lab of the ZEF/UNESCO project in Urgench

3.1 Primary canals Primary canals, or magistral canals according to the local classification system, are defined as those canals, which do not irrigate directly fields but supply water to the next level of channels, the secondary canals. Primary canals are locally called magistral (transboundary) and inter-rayon canals, and include those canals that supply water to different districts/rayons. The water flow in magistral canals is controlled by the BUIS and UPRADIK (Irrigation Canals Division), whereas the inter-rayon canals are controlled by UIS/TEZIM (Irrigation System Authority). The total length of the primary canals in the Khorezm region is 639 km (Fig. 9). The irrigation network density for these primary canals is thus 2.31 m ha-1.

Figure 9 Map of the primary irrigation canals in the Khorezm region of Uzbekistan

3.2 Secondary canals Secondary canals, which are locally called inter-farm canals, are fed by the water from the primary canals. These inter-farm canals are managed by canal heads, which function as an extended branch of UIS/TEZIM. The total length of the secondary canals in the Khorezm region is 1718.34 km (Fig. 10). The irrigation network density for these secondary canals is thus 6.21 m ha-1.

Figure 10 Map of the secondary irrigation canals in the Khorezm region of Uzbekistan

3.3 Tertiary canals Tertiary canals are those canals, which are fed with water from the secondary canals and convey it to the farm boundaries. Locally these canals are reckoned as on-farm canals and defined as the canals, which convey water from inter-farm canals to the farm level networks. The water distribution by on-farm canals is managed by the WCAs. The total length of these tertiary canals in the Khorezm region is 14,020 km (Fig. 11), which is equal to a network density of 51 m ha-1.

Figure 11 Map of the tertiary irrigation canals in the Khorezm region of Uzbekistan

4 DESIGN DISCHARGE OF CANALS IN DIFFERENT IRRIGATION SYSTEMS Water conveyance systems for irrigation, comprising of the primary, secondary and tertiary canals have to be properly designed. The design process comprises of finding out cross-section parameters, the longitudinal slope, length of the canals based on the design discharge for a given command area. The channels are made up of different construction materials. For example, the unlined canals can pass through soils which are erodible due to high water velocity, while some others may pass through stiff soils which may relatively be less prone to erosion. This would affect the longitudinal slopes of canals which would be different for canals passing through loose or stiff soils. In the following a set of tables is provided with information on the design parameters (length, design discharge) of the main/selected/available canals in the Toshsoka, Polvon-Gozovot, Shovot-Kulovot, and Koramazi-Kilichbay irrigation system. Data source is the GIS lab of ZEF/Khorezm project.

4.1 Overview of the irrigation system

Length, km Water intake points # Main canals Irrigated area, ha Total Concreted Total With pump

Toshsaka irrigation system 1 MK section 107.67 39.52 6006 16 2 R-5 section 175.46 21.75 22080 98 59 3 Pitnakarna section 37.9 2.1 6597 19 13 4 R. Sabirov section 186.0 41.27 20607 148 84 5 R-8 section 159.7 - 16551 82 53 Polvon-Gazavot system 6 R-9 section 50.4 4.5 4205 53 5 7 Nukus main canal section 90.6 8.6 11916 77 36 8 Nukus main canal section 201.33 25.58 17499 226 104 9 Keneges section 544 1.7 4914 84 41 10 Zey-Yop section 96.3 - 12760 127 101 11 Tugay-Yop section 81 - 12491 116 76 Shovot-Kulovot system 12 R-7 section 96.2 - 11459 101 66 13 Urganch-arna section 86.7 15.9 6700 55 25 14 Daryolik-arna section 237.5 15.8 20608 90 54 15 Kulovot section 178.8 12.2 12153 99 43 16 Beg Yop section 52.6 1.5 5507 25 18 17 Davdon Yop section 26.8 12.4 4566 23 3 18 Udachi Yop section 45.4 1.7 8796 56 30 19 Shovot-Kongli section 73 9.9 10603 60 46 20 Shovot-Begovot section 26.3 4.7 10115 72 66 21 KDOK section 150.84 14432 17 10 Karamazi-Kilichbay 22 Yangibazar section 11.2 6660 35 33 23 Alga section 18.8 3211 28 4 24 Kengesbaev section 27.2 9541 65 29 25 Gurlan vetka section 36.9 6225 50 34 26 Toksan arna section 48.53 14.25 3526 42 20 27 Karakuz section 58.45 6799 94 12 Total 2905.58 233.37 276527 1958 1065

4.2 Toshsoka irrigation system

Table 4 MK main canal of Toshsoka irrigation system Length, km Canal's water intake points Irrigated Canal name capacity, Concreted area, ha Total m3 s-1 total With pump Honka beton 3.6 3.55 3.0 100 1 - PК-0-PК35+50 Water bringing canal PK-0- 10.0 - 8.0 400 1 - PK-100 Birlashuv PK-0- 26.5 - 15.0 1403 4 - PK-265 МК-PK-0-PK- 28.6 28.6 15.0 1603 3 - 286 МК-uzak (duct) 2.7 - 5.0 300 1 - PK-0-PК-27 Rehabilitation done МК PK-0- 12.6 7.37 6.0 500 1 - PK-126 Water bringing canal PK-0- 0.7 - 14.0 - - PK-7 Water bringing canal Khiva- 10.0 - 8.0 800 2 - Khanka PK-0- PK-100 Water bringing canal Khazorasp- 8.4 - 4.0 500 2 - Gurlan PK-0- PK-83+50 Kizilkum canal 4.7 - 5.0 400 1 - Total 107.67 39.52 6006 16 -

Table 5 R-5 main canal of the Toshsoka irrigation system Length, km water intake points Canal's Irrigated Canal name capacity, area, ha total Concreted m3s-1 total With pump # 1 Korayantak 13.8 - 10.0 1943 5 4 2 As-Yop 17.8 - 3.5 1518 2 1 3 Kizilravat 12.0 - 3.0 1057 1 4 Besharik 18.7 - 25.0 2172 21 20 5 Birlashma 10.6 - 3.5 1391 1 - 6 Toma-Yop 13.7 - 4.0 2282 6 3 7 Hujalik 18.0 6.27 6.0 1522 4 2 8 Nayman 18.0 2.32 6.0 1952 17 3 9 Kungirod 19.0 0 3.5 1947 9 5 10 Atov 6.6 6.50 2.5 623 1 1 11 Kelajik 7.8 0 3.0 300 2 1 12 Bogot-Yop 11.6 0 15.0 140 1 - 13 Obod beton 6.66 6.66 5.0 440 1 - 14 Amu-daryo nasos - - - 1187 6 1 15 Bayramsaka 1.2 - 6.0 1845 11 11 16 Toshsoka - - - 1571 9 6 17 R-8 - - - 190 1 1 Total 175.46 21.75 22080 98 59

Table 6 Pitnakarna main canal of the Toshsoka irrigation system Length, km water intake points Canal's Irrigated Canal name capacity, area, With total Concreted m3s-1 ha total pump # 1 Pitnakarna 21.6 2.10 35.0 3031 4 1 2 Sheh-Yop 6.5 0 3.0 1404 2 3 MK 6.0 0 5.0 851 1 1 4 Yangi-Yop 3.8 0 2.0 145 5 4 5 Toshsoka - 0 - 1052 6 6 6 Amudarya - 0 - 114 1 1 Total 37.9 2.1 - 6597 19 13

Table 7 R. Sabirov main canal of the Toshsoka irrigation system water intake Length, km points Canal's Irrigated Canal name capacity, area, ha With Total Concreted m3s-1 total pump # 1 R. Sabirov 21.0 - 45.0 2339 11 8 2 HPK 13.2 - 1154 12 10 3 R-1 9.1 - 3.0 801 1 - 4 R-2 12.5 - 5.0 1070 1 - 5 Muhomon 15.0 - 3.8 637 1 - 6 Hossa-Yop 7.1 5.1 6.5 1749 9 8 7 R-4 3.7 - 2.0 953 1 8 R-3 8.4 - 6.0 1409 17 13 9 Left tributary (kozonli) 5.6 - 1.5 795 1 - 10 Yumalok 8.1 - 2.0 570 1 - 11 Urta Oyrik 5.6 - 2.0 630 1 - 12 Lesopitomnik 4.0 - 1.0 520 1 - 13 Mashin canal 10.7 - 3.5 588 1 - 14 Water distiobute canal 7.0 - 1.5 200 1 - Left tributary of Khorezm 15 5.0 1340 right bank canal 17.51 17.5 8 - 16 МК-2 7.18 7.18 5.0 1299 26 17 МК-1 10.8 10.8 6.0 510 9 1 18 Link canal (МНС) 0.68 0.68 2.7 - 19 Mashin canal НС 9.0 - 4.0 500 1 - 20 Khazarasp canal link 0.76 - 4.0 1 - 21 Nasosniy orasi 5.8 - 2.0 105 1 - 22 Kirov-Yop 3.27 - - 89 1 - 23 nasos Amudarya - - - 500 9 11 24 nasos Toshsoka - - - 2704 24 24 25 nasos Bayramsoka - - - 145 3 3 26 nasos R-3а - - - 6 6 Total 186.0 41.27 20607 148 84

Table 8 R-8 main canal of Toshsoka irrigation system water intake Length, km points Canal's Irrigated Canal name capacity, area, ha With total Concreted m3s-1 total pump # 1 Yangiraik 27.0 - 60.0 1887 18 16 2 Kuriktom 21.9 - 16.0 2131 13 12 3 Olga 6.5 - 2.0 535 1 4 Pursang 8.5 - 9.0 2461 15 9 5 Ostona 6.5 - 20.0 1644 7 6 6 Hon-Yop 8.2 - 2.0 245 1 - 7 Beshayvon 3.4 - 1.8 218 1 - 8 Boyot 7.0 - 1.5 489 3 - 9 Kushlok 8.0 - 2.0 589 1 - 10 Karakuz 5.4 - 2.0 597 - 11 Ok machit 15.7 - 9.5 2452 7 4 12 Egizak 5.1 - 1.5 517 1 - 13 Uygur 4.3 - 1.5 361 1 - 14 Kattabor 10.3 - 8.0 1338 9 6 15 Karmish -Yop 6.3 - 4.0 332 1 - 16 Tagan 3.6 - 2.0 482 1 - 17 Gullanbog (novruz) 3.0 - - - - - 18 Shursolma 2.1 - 3.0 157 1 - 19 Mustakillik 6.9 - 2.5 116 1 - Total 159.7 - 16551 82 53

4.3 Palvon- Gazovot irrigation system Table 9 P-9a main canal of Palvon Gazovot irrigation system Length, km Water intake points Irrigated # Main canals Total Concreted area, ha Total With pump

1 P-9 50.4 4.5 4205 58 5 2 Nukus Yop 90.6 8.6 11916 77 36 3 Polvon 201.63 25.5 17499 226 104 4 Keneges 54.4 1.7 4914 84 41 5 Zey Yop 96.3 - 12760 127 101 6 Tugay Yop 81 - 12491 116 76 Total 574.33 40.3 63785 688 363

Table 10 P-9 main canal of Polvon-Gazovot irrigation system Water intake Length, km Canal's points Irrigated # Canal capacity, area, ha With Total Concreted m3s-1 Total pump 1 P-9 19 0.8 2222 12 24 5 2 Madir Yop 1 13.1 - 633 3.5 9 - 3 Madir Yop 2 11.3 - 600 3.5 1 - 4 Mulla Yop 5 3.7 420 1.5 12 - 5 Jamma 2 - 330 1 7 - Total 50.4 4.5 4205 15.5 53 5

Table 11 Nukusa main canal of Polvon-Gazovot irrigation system Water intake Length, km Canal's points Irrigated # Canal capacity, area, ha With Total Concretedm3s-1 Total pump 1 Kazak Yop 5.3 1.7 252 1 1 - 2 Navoiy Yop 16.5 2.4 881 2 5 - 3 Korakopsh Yop 5.7 - 457 2 6 - 4 Nukus Yop 1 23 - 1495 12 17 2 5 Nukus Yop 2 12.5 4.5 824 5 1 - 6 Durgadik 3.5 - - - - - 7 Sherobod 17.1 - 2115 6 8 1 8 Gaybu Yop 7 - 582 1.5 6 - 9 Polvon-Gazovot - - 5310 19.2 33 33 Total 90.6 8.6 11916 51.2 77 36

Table 12 Nukus main canal of Polvon-Gazovot irrigation system Length, km Water intake points Canal's Irrigated # Canal capacity, area, ha Total Concreted m3s-1 Total With pump 1 Polvon 13 - 3303 54 20 18 2 Sayt 17.23 - 1319 6.5 21 12 3 Irdimzan 14.1 - 1475 2 9 - 4 Birlashken 8.5 - 616 1 5 - 5 Pahtakor 12.2 - 197 2 1 - 6 Gurlenbog 8.7 - 584 1 1 - 7 Pirnahos 10.6 1.18 1066 5 17 7 8 Ziri Yop 6.3 - 58 1 1 - 9 Pishkenik 14.3 - 1043 5.5 17 10 10 Ak-Yop 18.5 1.2 2190 10 26 19 11 Angarik 2.5 - 211 1 11 2 12 Humbuz 6.6 1.05 378 2 6 1 13 Shihlar Yop 4 - 122 1.5 9 1 14 Sirchali 7.3 3.06 530 2.5 16 5 15 Kenik 4.2 - 380 1.5 3 1 16 Dashyak 6 2 254 1 7 3 17 Horosan 8.6 - 180 1.5 9 2 18 Gauk 12.7 929 1769 14 24 13 19 Boz-Yop 7.6 7.8 414 2 7 3 20 Korpkup 8.6 - 1410 6 16 6

21 Khiva kanal 5.9 - - 2 - - 22 Gurlanbag 3.9 1 (link) - - - - Total 201.33 25.58 17499 226 104

Table 13 Keneges main canal of Polvon-Gazovot irrigation system Length, km Water intake points Canal's Irrigated # Canal capacity, With Total Concreted area, ha 3 -1 Total m s pump 1 Keneges 16 1.7 1356 12 10 4 2 Eski Hanobod 19.9 - 1348 3 40 17 3 Hanobod 1 15.7 - 1624 8 20 9 4 Katta keneges 6.5 - 364 20 11 3 5 Hadra Yop 5.3 - - - - - Total 544 1.7 4914 43 84 41

Table 14 Zey-Yop main canal of Polvon-Gazovot irrigation system Length, km Water intake points Canal's Irrigated # Canal capacity, area, ha Total Concreted m3s-1 Total With pump 1 Zey-Yop 41 - 7321 25 85 64 2 Hanobod-2 23.8 - 3667 8 40 37 3 Hanobod-3 12.5 - 650 6 1 - 4 Hosiyan Yop 7 - 1122 6 1 - 5 Tagalak 7.5 - - 3 - - 6 Boyavul Yop (on the 3 - - 1 - - balance of WCA) Total 96.3 - 12760 28 127 101

Table 15 Tugay-Yop main canal of Polvon-Gazovot irrigation system Length, km Water intake points Canal's Irrigated # Canal capacity, area, ha Total Concreted m3s-1 Total With pump 1 Uzbek Yop 6.5 - 760 3.8 1 - 2 Tugay Yop 25.5 - 2819 14.6 32 6 3 Ok-Yop 7.9 - 847 3 13 2 4 Gazovotr Yop 3.5 - - - - - 5 Tugayyap (link) 1.3 - - - - - 6 Davdon Yop 3.5 - - - - - 7 Amirkul-Yop 3.5 - 501 5.3 2 2 8 Gurvak-Yop 25 - - - - - 9 Mast-Yop 6.6 - - - - - 10 Masharip Rahimov 2 2.5 - - - - - 11 Masharip Rahimov 3 4 - - - - - 12 Ohunboboev 2 - - - - - 13 Shih Yop 2.5 - - - - - 14 Uzbek Yop 2 6.5 - - - - - 15 Gazovot kanali - - 7564 32.3 68 66 Total 81 - 12491 55.2 116 76

4.4 Shovot-Kulovot irrigation system Table 16 R-7 main canal of Shovot-Kulovot irrigation system Length, km water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 R-7а 22.5 - 75.0 5224 33 20 2 Left line of R-7а 12.1 - 15.0 1485 16 1 3 L-15 3.1 - 1.0 123 1 - 4 L-17 4.1 - 1.0 132 1 - 5 L-19 3.7 - 1.0 145 1 - 6 Huja-yorgan 5.7 - 5.0 1080 3 - 7 Urganch-arna 13.6 - 100.0 505 14 14 8 Daryolik-arna 16.5 - 100.0 806 20 19 9 Karamazi Yop 14.9 - 4.0 194 10 10 10 Amudarya - 1765 2 2 Total 96.2 - 11459 101 66 31

Table 17 Urganch-arna main canal of Shovot-Kulovot irrigation system Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 Urganch-arna 9.6 - 18.0 887 10 10 2 Kozok Yop 13.6 - 6.0 1229 11 10 3 Dustlik Yop 6.4 4.1 4.0 593 19 5 4 Durman Yop 17.2 - 11.0 2456 7 - 5 Kaysar 9.8 - 5.0 250 1 - 6 Ukchi 11.7 3.0 150 1 7 Chakka Yop 3.6 3.6 2.0 300 2 - 8 Kirgiz Yop 10.7 7.8 3.0 635 3 - Link for 9 Dustlikyap and 0.4 0.4 0.5 - Chakkayap 10 Ung Yarmish 3.7 2.0 200 1 Total 86.7 15.9 6700 55 25

Table 18 Daryolik-arna main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigate # Canal name capacity, d area, Total Concretedm3s-1 ha Total With pump

1 Buston Yop 14.0 - 12.0 1508 2 2 Hayvat Yop 11.0 - 5.0 1700 1 3 Uygur Yop 14.0 - 5.0 490 5 4 4 Deliver canal Daryolik 9.4 - 4.0 Kumyap bagalanyap link 5 3.7 - 2.0 (tail end) 6 Bogolon Yop 15.6 - 4.5 720 2 1 7 Kiyot Kungirot 8.6 1.8 9.0 1160 1 8 Buz-acha 13.0 4.8 1300 1 (Kilichboy) deliver canal of 9 heads of Bogolon Yop and 7.0 - 2.0 Kum YopКум-яп, 10 Boshkir Yop 5.6 - 3.0 200 1 11 Shirin-acha 13.0 - 4.8 2072 1 12 Kum Yop 14.0 14.0 4.0 260 1 13 Interdistrict Daryolik-arna 10.5 - 50.0 3241 17 17 14 Daryolik-arna 10.2 - 40.0 1340 8 5 15 Eski-Daryolik 14.5 - 7.0 1075 2 16 C-l Daryolik 9.0 - 12.0 1000 2 17 Uyrat-yab link 4.5 - 2.0 - - - 18 Chavdir yab link 18.0 - 8.0 618 16 12 19 Xayvat uygur yap link 4.3 - 3.0 - - - 20 Bustan yap link 4.5 - 2.0 - - - 21 Tugoy-obod 13.6 - 14.0 1315 16 9 22 Left line of Tugoy-obod 10.1 - 1.5 300 3 1 23 Tugay abad link 2.0 - 4.0 800 2 - 24 Water bringing canal 0.7 - 5.0 - 25 Tugoy Yop 6.7 - 1.5 442 4 - 26 Daryalik tashlama - 1067 5 5 Total 237.5 15.8 20608 90 54

Table 19 Kulovot main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigate # Canal name capacity, d area, Total Concreted m3s-1 ha Total With pump

1 Kulovot canal 35.6 - 25.0 3238 33 24 2 Chandir Yop 9.5 - 2.0 295 1 3 Kum Yop (Urganch) 6.3 - 6.0 651 1 4 Laylak Yop 11.0 - 5.0 639 18 15 5 Begovot Yop 8.2 - 5.0 1320 5 - 6 Daud Yop 3.1 - 2.0 500 1 - 7 Kulavat link (gazavat) 6.1 - 10.0 - 8 Ogorod salma 5.7 - 1.0 340 1 - 9 Leskhoz salma 5.0 - 3.0 300 1 - Left line of Kum Yop 10 (Urganch) 17.2 - 8.0 700 1 - 11 Kumyap concrete (telecenter) 0.3 - 0.5 10 1 - 12 Right line of Kulovot 17.2 12.2 12.0 2180 28 4 13 Left line of Kulovot (Urganch) 18.8 - 4.0 600 3 - 14 Kum Yop -1 3.0 - 0.7 100 1 - 15 Kum Yop -2 6.0 - 0.7 150 1 - 16 Istiklol 5.0 - 1.5 610 1 - 17 Mustakillik 6.5 - 5.0 420 1 - 18 Kulavat left bank 14.3 - 3.0 100 1 - Total 178.8 12.2 12153 99 43

Table 20 Beg Yop main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 Beg Yop 36.0 1.5 15.0 4177 19 18 2 Hitoy Yop 11.0 - 3.0 944 4 - 3 Buston Yop 2.5 - 1.0 205 1 - 4 Kum Yop 3.1 - 0.7 181 1 - Total 52.6 1.5 5507 25 18

Table 21 "Davdon Yop" main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 Dovdon 23.4 12.4 14.0 4473 22 3 2 Tugoy Yop 3.4 0.7 93 1 Total 26.8 12.4 4566 23 3

Table 22 Udachi Yop main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 Udachi 28.7 1.7 11.0 4058 29 10 2 Udachi-1 1.7 - 1.0 280 4 - 3 Hassa Yop 10 - 3.0 960 2 - 4 Yarmish solma 5 - 1.0 160 1 1 Turkman- 5 yarmish - - - 3338 20 19 Total 45.4 1.7 8796 56 30

Table 23 Shovot-Kongli main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concreted m3s-1 Total With pump # 1 Shovot 4586 43 42 2 Otalik 8.0 8.0 3.0 780 1 3 Kishlok Yop 13.4 - 3.0 750 1 4 Ushaktam 8.5 - 3.0 575 5 4 5 Ruzim Yop 4.7 - 2.0 367 1 - 6 Buz Yop 7.0 - 2.0 907 1 - 7 Manak Yop 4.1 - 1.5 240 1 - 8 Somonli 4.2 - 2.0 421 1 - 9 Akbashli 4.1 - 2.0 420 1 - Uzbekiston 10 Yop 3.8 - 1.0 280 1 - 11 Mahtumkuli 3.0 - 1.5 210 1 - 12 Kangli Yop 7.3 - 2.0 582 1 - 13 Guliston 1.9 1.9 1.0 170 1 - 14 Eshvoy 3 - 0.5 315 1 - Total 73 9.9 10603 60 46

Table 24 Shovot-Begovot main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, area, ha Total Concretedm3s-1 Total With pump # 1 Canal Ok-oltin 6.2 4.0 160 2 - 2 Chakka yap link 2.7 2.7 0.5 - - - 3 Sub Begavatyap 2.7 15.0 412 7 7 4 R-1 3.5 2 734 1 - 5 Davdon Yop 6.6 - 0.5 549 1 - 6 Dustlik Yop 4.6 - 3.5 1300 2 - 7 Shavat - - 6960 59 59 Total 26.3 4.7 10115 72 66

Table 25 KDOK main canal of Shovot-Kulovot Irrigation System Length, km Water intake points Canal's Irrigated Canal name capacity, Including Total Concreted 3 -1 area, ha Total m s pump # 1 Dustlik 14.2 - 6.0 1645 1 - 2 МК-1 5.5 - 5.0 - - 3 М-2 25.0 - 8.0 3966 1 1 4 М-1 11.0 - 5.0 812 1 5 canal KDOK 37.9 - 12.0 4000 1 1 Taldikyap right 6 bank 10.7 - 5.0 418 2 - Canal left bank 7 KDOK 12.8 - 5.0 429 1 - 8 Kipchak Yop 16.04 - 3.0 840 1 - 9 Gurlan Yop 17.7 - 6.0 - - - 10 Ak-Bashli - - 1322 7 6 - 11 Amudarya - - 1000 2 2 - Total 150.84 - 14432 17 10

4.5 Karamazi-Kilichbay irrigation system Table 26 Yangibazar main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Klichbay - - - 940 4 4 2 Line Klichbay - - - 1620 5 5 3 Amudarya - - - 2230 5 5 4 Turangi saka - - - 1270 17 17 5 Turangi obod - - - 400 1 - 6 Amu - 1 6.2 - 3.0 100 1 1 7 Amu - 2 5.0 - 3.0 100 1 1 8 Sbros canal - - 1 - Total 11.2 - - 6660 35 33

Table 27 Alga main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Alga yab 14.2 - 4.0 1923 19 - 2 Klichbay - 1198 5 4 Taksan arna 3 link 4.6 - 5.0 100 4 - Total 18.8 - 3211 28 4

Table 28 Kengesbaev main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Klichbay - 2394 22 21 2 Kengesbaev 9.7 - 25.0 655 6 - 3 Savo Yop 11.0 - 10.0 4131 29 3 4 Dukanbay 6.5 - 5.0 1751 4 1 5 Jamshid - 510 4 4 Total 27.2 - 9541 65 29

Table 29 Gurlan vetka main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Gurlan vetka 27.0 - 60.0 4351 41 30 Yangi yab 2 Gurlan 9.9 - 4.0 1654 4 1 Yangi yab 3 (Kipchak) - - 220 5 3 Total 36.9 - - 6225 50 34

Table 30 Toksan arna main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Toksan arna 3.0 1.0 10.0 140 1 1 2 Nukus yab 24.8 7.9 6.0 2187 29 11 3 Hizir eli 20.73 5.35 4.0 1199 12 8 Total 48.53 14.25 3526 42 20

Table 31 Karakuz main canal of Karamazi-Kilichbay Irrigation System water intake Length, km points Canal's Name of the Irrigated № capacity, canal area, ha With Total Concreted m3s-1 Total pumps

1 Karakuz 19.0 - 15.0 2855 35 7 2 Toza-targan 12.0 - 3.0 1156 31 2 3 Amudarya - 588 2 2 4 Kayir yab 14.35 - 10.0 1018 22 1 5 Saratov 11.0 - 11.0 1120 1 6 Karakuz link 2.1 - 5.0 62 3 Total 58.45 - - 6799 94 12

5 IRRIGATION NETWORK EFFICIENCY OF SOME OF THE MAIN CANALS Irrigation network efficiency is defined as the ratio of the water available at the tail of the canal to the water available at the head of the canal. It indirectly is a measure of the conveyance and distribution losses in the irrigation network. The estimated network efficiencies of various channels are summarized in Table 32.

Table 32 Irrigation network efficiency of selected main canals Efficiency Efficiency Efficiency Canal District (%) Canal District (%) Canal District (%) R - 7b Bagat 93.6 Kazak - yab Urgench 93.6 Birlashgan Khiva 90.4 sbr K.Rоvоt Bagat 93.4 Urgancharna Urgench 93.6 Sоyot Khiva 90.4 K.Yantоk Bagat 93.4 Daryolik arna Urgench 93.6 Kеnеgеs Khiva 90.4 As – yab Bagat 93.4 Tugоy оbоd Urgench 93.6 Pоlvоn Khiva 90.4 sbrDaryolikarn R - 7 a Bagat 93.6 AD Urgench 100 nas.P.Gazavat Khiva 90.4 R – 5 Bagat 93.6 Amudarya Urgench 100 nas.Gоzоvоt Khiva 90.4 Nukus – yab Bagat 93.7 nas. Bayram Khazarasp 94.3 Dоvdоn Shavat 90.4 R – 8 Bagat 93.7 R - 3 Khazarasp 93.2 Bеg – yab Shavat 90.1 nas.Tashsaka Bagat 93.6 ХОK Khazarasp 93.8 Хassa Shavat 90.2 nas.Bayram Bagat 94.3 ХPK (R - 3a) Khazarasp 93.8 Udachi Shavat 90.1 Amudarya Bagat 100 nas.Tashsaka Khazarasp 93.2 nas.Shоvоt Shavat 90.1 Daryolik arna Gurlan 93.6 Pitnak arna Khazarasp 100 nas.T.YArmish Shavat 90.2 Gurlanvеtka Gurlan 92.5 Amudarya Khazarasp 100 R – 8 Yangiarik 91.3 Kilichbоyvеt Gurlan 92.5 Kulоvоt Khanka 94.2 SHеrоbоd Yangiarik 90.4 Amudarya Gurlan 100 R - 9 Khanka 93.8 nas.T.YArmish Yangibazar 90.2 Pоlvоn Kushkupir 90.4 R - 8 Khanka 93.7 nas.SHоvоt Yangibazar 90.5 Kеnеgеs Kushkupir 90.4 R - 7a Khanka 93.6 Gurlanvеtka Yangibazar 92.5 Gazavat Kushkupir 90.4 Nukus - yab Khanka 93.7 Kilichbоyvеt Yangibazar 92.5 Kulоvоt Kushkupir 90.8 nas.SHоvоt Khanka 94.3 Turangi saka Yangibazar 92.5 Davdоn Urgench 90.4 Madir yab Khanka 93.8 Daryolik arna Yangibazar 93.6 Kulоvоt Urgench 90.8 Gaybu - yab Khanka 90.5 Tugоy оbоd Yangibazar 93.6 nas.SHоvоt Urgench 90.7 nas.P.Gazavat Khanka 90.8 Urganch arna Yangibazar 93.6 Urganch arna Gaybu – yab Urgench 90.5 v/b Khanka 93.6 Amudarya Yangibazar 100 Daryolik arna nas.Gоzоvоt Urgench 90.4 v/b Khanka 100 nas.LBK Pitnak 94 Bеgavat – yab Urgench 90.7 Amudarya Khanka 100 Pitnak arna Pitnak 100 Urganch arna Urgench 93.6 Irdimzan Khiva 90.4 Amudarya Pitnak 100

6 LIFT IRRIGATION SCHEMES IN THE REGION As canals of high hierarchy level are dug-in in the region, the water needs to be pumped up into the distribution canals. However, depending on the topography, some farms receive irrigation water directly from the dug-in canals. The present datasets indicated that about 55% of the total water supply to farmer’s field is ensured through lift irrigation schemes using pumps (Table 33), whereas the remaining 45% has surface water supply through gravity canals. The pumping stations which supply water directly to the WCAs are under the control of the WCAs. However, pumping stations, which operate at the level of magistral or inter- rayon canals are operated by UNU (Management Organization of Pumping Stations).

Table 33 Lift irrigation schemes in the Khorezm region of Uzbekistan Electric pump stations Diesel pump stations Total No. of No. of No. of Total no. of Total Districts electric installed Associated diesel capacity Associated pump capacity pump aggregates area (ha) pump (horse area (ha) stations (kW) stations (pumps) stations power) Baghat 142 118 118 7183 9842 24 3120 1656 Gurlen 123 117 117 5959 10943 6 780 797 Kushkupir 226 170 170 9972 11787 56 7280 3472 Urgench 209 168 168 9242 9023 41 5330 1381 Khazarasp 196 166 166 10679 14295 30 3900 1359 Khanka 77 68 68 5059 5988 9 1170 292 Khiva 125 113 113 7120 9849 12 1560 618 Shavat 156 145 145 9785 15485 11 1430 472 Yangiarik 85 60 60 4336 5606 25 3250 1748 Yangibazar 191 185 185 11609 13233 6 780 148 Regional 1530 1310 1310 80944 106051 220 28600 11943 Source: GIS lab of the ZEF/UNESCO project in Urgench

7 DRAINAGE NETWORK IN THE KHOREZM OASIS An open horizontal drainage network is used to remove excess surface and groundwater from the area along with the salts, the latter especially stemming from leaching events prior to the vegetation season. The drainage network consists of laterals and collectors. The overall length of the drains and collectors in the irrigation and drainage system is 8,790 km. The drainage density of the drainage network (length of drains per unit hectare of irrigated land) amounted to 31.78 m ha-1 based on an irrigated area of 276,600 ha.

7.1 Collectors The total length of the collectors (defined as ditches which takes the water directly from the drains and convey this drainage water out of the system) is 3,290 km (Fig. 12), which is equal to a network density of 11.89 m ha-1.

Figure 12 Map of the main collectors in the Khorezm oasis of Uzbekistan

7.2 Drains Drains and lateral (field drains) are defined here as those ditches which operate at field level, collect the water from the fields and convey it to the collectors. According to the GIS-based maps (Fig. 13), the total length of drains in the Khorezm region is 5,500 km, which is equal to a network density of 19.88 m ha-1.

Figure 13 Map of the drains in the Khorezm region of Uzbekistan

8 SUMMARY AND CONCLUSIONS The irrigation network in the Khorezm region comprises of primary, secondary and tertiary canals which supply water to the crops either by the lift irrigation schemes or by gravity flow. Along with the dense irrigation system, also a dense drainage infrastructure exists. Although, drainage efficiency is nevertheless poor at various places in the Khorezm region due to the bottlenecks at the outlet of the main collectors, the existing drainage infrastructure still allows maintaining the groundwater levels at an acceptable limit. This makes the existing irrigation and drainage infrastructure suitable for intensive agriculture. However, the sustainability of the irrigation and drainage systems are questionable. High irrigation efficiency through main earthen canals is due to the strong interaction between the full supply level of canals and the groundwater levels. During the vegetation season, some canals act as drains i.e., movement of groundwater into the irrigation canals. This results in exfiltration rather than seepage from canals. However, in tertiary canal system, the water losses are high as interaction between the canals and the groundwater levels consists of percolation and seepage.

9 REFERENCES

Conrad, C (2006) "Fernerkundungsbasierte Modellierung und hydrologische Messungen zur Analyse und Bewertung der landwirtschaftlichen Wassernutzung in der Region Khorezm (Usbekistan). (In English): Remote sensing based modeling and hydrological measurements for the assessment of agricultural water use in the Khorezm region (Uzbekistan). Dissertation." University of Würzburg, Germany.

Dukhovny, V. A. and V. Sokolov. 2001. Diagnostic Study. Rational and Effective Use of Water Resources in Central Asia. UN-Special Program For Economics of Central Asia. Tashkent, Uzbekistan and –Bishkek, Kyrkyzstan.

Fayzullaev BF (1985) The influence of cotton irrigation from the Tuyamuyun reservoir to the soil conditions and cotton yield and to develop agrotechnical negative impact of irrigation water quality change. Archives of SANIIRI, NTO, Tashkent, 1985.

Froebrich J, Bos M, and Wegerich K (2007). "Editorial." Irrigation and Drainage Systems, 21(3), 159-160.

Ibrakhimov, M., Khamzina, A., Forkutsa, I., Paluasheva, G., Lamers, J.P.A., Tischbein, B., Vlek, P.L.G., Martius, C. 2007. Groundwater table and salinity: Spatial and temporal distribution and influence on soil salinization in Khorezm region (Uzbekistan, Aral Sea Basin). Irrig. Drainage Syst. 21 (3-4), 219-236. Online at DOI 10.1007/s10795-007-9033-3

Jabbarov H. 2005. Irrigation canals and collector-drainage systems in Khorezm. Internal report of the ZEF/UNESCO project Urgench. 35 pages. In Russian

Nasonov, 2007 Collector-drainage system development in the Khorezm oasis and ways for drainage improvement. Internal report of the ZEF/UNESCO project Urgench. 23 pages in Russiann.

Conrad C, Schorcht G, Tischbein B, Davletov S, Sultonov M, Lamers JPA (2012) Agro- meteorological trends of recent climate development in Khorezm and implications for crop production. In: Martius C, Rudenko I, Lamers JPA, Vlek PLG (Eds.) Cotton, water, salts and soums - economic and ecological restructuring in Khorezm, Uzbekistan. Springer: Dordrecht, Heidelberg, London, New York, pp. 25-36 van Assche K, Djanibekov N (2011) Spatial planning as policy integration: The need for an evolutionary perspective. Lessons from Uzbekistan. Land Use Policy, doi:10.1016/j.landusepol.2011.06.004

Veldwisch GJ (2007) Changing patterns of water distribution under the influence of land reforms and simultaneous WUA establishment: Two cases from Khorezm, Uzbekistan. Irrig Drain Syst 21(3-4): 265-276

10 APPENDIX -1 Annex 1: Monthly averages of the daily ETo (mm d ) from 1985-2009

ET (mm day-1)

Year-Month J F M A M J J A S O N D Total/Year

1985 0.42 1.23 1.79 5.11 6.13 7.50 6.56 5.19 4.30 2.10 1.48 0.50 1291

1986 0.43 1.29 1.93 4.78 6.08 7.39 7.35 5.85 4.63 2.53 1.38 0.49 1347

1987 0.91 1.00 1.53 3.10 6.78 7.74 6.92 6.07 3.75 2.35 1.65 0.68 1299

1988 0.66 0.84 2.20 4.80 5.96 7.83 6.90 5.63 3.81 2.68 1.39 1.00 1335

1989 0.56 1.06 2.47 4.31 5.85 7.00 7.49 5.75 4.18 3.01 1.21 0.60 1330

1990 0.50 1.13 2.46 4.02 7.07 8.24 6.65 5.81 4.71 2.42 1.56 0.80 1385

1991 0.59 1.12 2.33 4.31 5.20 7.27 7.37 6.14 4.27 2.63 1.17 0.73 1318

1992 0.55 0.93 1.98 4.14 5.13 7.39 7.35 5.53 4.53 2.72 1.50 0.74 1297

1993 0.74 0.94 2.04 4.41 6.03 7.80 7.03 5.44 4.30 2.47 0.81 0.36 1294

1994 0.55 0.95 2.05 4.28 6.28 7.27 6.71 6.19 4.21 2.80 1.03 0.81 1319

1995 0.79 1.05 2.23 5.76 6.29 7.07 7.08 5.99 4.22 2.38 1.94 0.77 1391

1996 0.78 1.07 2.32 3.80 6.21 7.58 7.07 6.48 5.07 3.22 1.50 1.27 1417

1997 0.81 1.34 2.36 4.46 6.06 7.67 7.19 6.39 4.31 2.81 1.49 0.70 1393

1998 0.43 0.90 1.84 4.92 5.78 7.65 7.48 5.90 4.67 2.78 1.90 0.81 1376

1999 0.98 1.85 2.76 4.69 6.61 7.83 6.90 6.65 4.28 2.84 1.00 0.70 1438

2000 0.72 1.41 2.72 5.36 6.83 7.47 7.53 6.45 4.41 2.09 1.42 0.54 1434

2001 0.53 1.37 2.99 5.02 6.83 7.97 7.38 5.71 4.56 2.42 1.12 1.01 1433

2002 0.79 1.26 3.39 4.11 5.87 7.21 6.85 5.75 4.32 3.13 1.62 0.46 1367

2003 0.65 1.07 1.92 4.25 5.00 6.35 7.43 6.51 4.84 3.26 1.28 1.03 1332

2004 0.80 2.01 3.41 4.10 6.94 8.26 6.99 6.81 4.90 2.71 1.32 0.85 1499

2005 0.66 0.95 2.92 5.06 6.11 7.57 7.31 6.03 5.21 3.13 1.43 0.72 1439

2006 0.55 1.29 2.77 4.85 6.71 7.93 7.49 6.59 4.46 2.70 1.55 0.61 1451

2007 1.04 1.25 2.38 3.97 6.74 8.01 7.16 6.59 4.78 2.87 1.71 0.71 1443 0.64 1.15 2.35 4.38 6.03 7.36 6.94 5.91 4.34 2.60 1.36 0.72 Average 1375

Annex 2: Monthly precipitation values (mm) from 1985-2009

Month/Year J F M A M J J A S O N D Total/Year

1985 8.2 35 19.3 0 19.3 0 0 13 2.2 6.3 0 3.9 107

1986 11.6 0 5.2 2.2 10.6 0 2.4 0 0 1 6.9 20.7 61

1987 0 28.5 21.1 23.1 0.7 2.8 3.6 0 0 1.6 10.7 19.2 111

1988 9.2 13.3 18.6 0 1.1 3.6 0 1.5 1.1 0.4 5.6 16.7 71

1989 14.5 7 45.8 0.6 9.8 0.6 0 0 8.6 0 0.7 11.8 99

1990 6.3 6.8 2.1 25.1 2.7 6.9 1.2 0.4 0 16.7 6.3 6.7 81

1991 8 6.3 5.2 10.7 61.2 5.8 0.3 0 7.5 0 18.8 4.8 129

1992 35.7 28.5 1.9 25.2 15.7 4.1 0 7.9 0 2.5 0.9 41.5 164

1993 9.7 10.4 25 12.3 0.3 22.1 1.1 0 0 0 37.4 8.9 127

1994 21.4 6 28.7 0 13.5 0.3 0 0.4 0 2.9 26.9 6.7 107

1995 7.5 10.4 3.7 0 2.7 0 0 0 2.7 0 5.6 2.2 35

1996 6.1 11.7 5.4 14.9 2.8 0 0 0 0 7 0 0 48

1997 11.8 2.5 18.5 32.3 11.9 0.9 0 0 0 2.6 7.3 4.3 92

1998 34.7 13 28.3 2.5 14.8 4.6 0 3.6 1.2 1.9 0 1.4 106

1999 0.7 2.2 4.6 17.4 0.7 0 9.1 7 4.6 5.5 36.5 0 88

2000 8.4 3.5 11.4 3.9 0.3 2 0 3.3 2.2 10.3 0.8 6.6 53

2001 5.1 5.4 25.6 3.9 13.9 0 1.9 2.1 0 25.9 6.7 10.3 101

2002 7.6 16.5 1.9 33.4 2.5 28.8 0 20 0 0 0.9 3.3 115

2003 14.3 17.1 21.9 13.9 54.4 12.6 0 0 2.3 2.6 6.7 4.9 151

2004 0.6 9.5 1.1 35.8 2.6 8.4 1.7 0 0 4.3 27.8 12.5 104

2005 26.8 1.4 5.9 7.5 10.7 0 0 3.5 0 0 1.9 60.7 118

2006 21.3 5.1 24.1 7.9 0.5 0 1.4 0 0.5 4.2 21.3 21.6 108

2007 2.4 2.3 48.8 42.6 0.8 1 0.3 0 0 4 2.4 23.3 128

2008 0 19.6 1.8 5.6 11.4 0 0.8 0 5.2 19.2 0 0 64

2009 0.4 3.2 10.8 5.4 7 0.2 0 0 1.5 0 13 1 43 10.89 10.61 15.47 13.05 10.88 4.19 0.95 2.51 1.58 4.76 9.81 11.72 Total 96