DEPARTMENT OF WATER RESOURCES OF THE PYANJ BASIN ZONE

06:17:48

January    
Mon 24-01-2022

Irrigation and Drainage

Agriculture is the largest consumer of water in the Pyanj Basin. The need for irrigation for agricultural production is long-established, with agriculture relying only on rainfall is unreliable and of low productivity. There are rain-fed areas of agriculture in higher lands with poor soils where crops have low water requirements and might fail completely during the long dry summers.

During the Soviet period extensive irrigation systems were built to provide irrigation water to suitable land. Suitable land is mostly found in river valleys, or on terraces formed in earlier geological time along the river valleys. Much of the irrigated land was fed through pumped systems and developed when charges for energy needed to lift water through pumping were negligible.

Since the end of the Soviet period many irrigation systems have fallen into disrepair, especially in those areas fed through pumping stations and pumping cascades. Much of the antiquated electrical and mechanical equipment became inoperable and is slowly being replaced when funds are made available for rehabilitation of systems. The water distribution systems in the lift areas have also become unusable through loss of canalette sections and general abandonment of land once irrigated.

Sources of water for irrigation are very largely river systems – with little groundwater used. River water quality is generally very suitable for irrigation but has a high sediment load mostly. In general, there is plenty of water available for irrigation use, but little land suitable and economic under present conditions for profitable agriculture.

In the Soviet period some of the irrigated areas were also provided with drainage systems. These are usually open channel networks of drains discharging through gravity back into the river system – although some pipe drains are also present. These have had little maintenance since the end of the Soviet period and have become blocked and filled with sediments greatly restricting the capacity of the systems. The reduced performance of the drainage systems has not severely impacted on agricultural production as irrigation water application rates have been restricted in recent times due to issues of maintenance of the supply systems. But with attention given to rehabilitation of irrigation systems there will be a need to provide appropriate improvement in the drainage networks to avoid problems of waterlogging and salinization of the fields.

Management of the irrigation and drainage network to the farm level is the responsibility of the Agency for Land Reclamation and Irrigation (ALRI). At the field level, the organization of Water Users Association in being developed to assume responsibility for management of the tertiary level of irrigation systems, the distribution of water to field outlets, and collection of dues for payment to local ALRI units for water supply.

Monitoring of the performance of the irrigation and drainage systems of the basin has also been problematic since the Soviet period, with reported hydraulic information based on water levels unsupported by actual measurements of flows in the system. In poorly maintained systems, conversion of water levels to estimated discharges is not accurate and can be misleading.

Irrigation Canals

The total irrigated area is 170,142 ha and is divided into 2,452 schemes. Out of these, 2,013 have an area of up to 5 ha and 439 – areas ranging from 5 to 10 ha. The total length of the canals is 7,266 km, of which 206 km are lined. The canals are equipped with 543 structures on the main network and 742 field delivery points. The outlets have a total of 1,206 gauging stations. In addition, there are 6,077 km of operational on-farm canals, of which 104 km are lined.

The Kulyab irrigation system is characterized by long conveyance canal sections and significant water losses due to filtration. The overall system efficiency is 0.58. The intake structure of the Farharo-Chubek irrigation system is located at the head of the “Dekhkanabad” main canal. The efficiency of the unlined irrigation canal network is 0.62.

Table 1: Length of Irrigation Canals in the Pyanj River Basin

Water resource zone District Length of irrigation canals (km) Total (km)
Inter-farm On-farm
Kulyab Jaykhun 217.9 436.3 654.2
Pyanj 136.3 387.3 523.6
Sub-total 354.2 823.6 1,177.8
Baljuvon 0.0 0.0 0.0
Vose 113.0 470.0 583.0
Dangara 85.0 317.0 402.0
Kulyab 65.0 319.0 384.0
Muminabad 0.0 0.0 0.0
Temurmalik 0.0 233.1 233.1
Farkhor 224.0 413.0 637.0
Hamadoni 114.0 477.0 591.0
Khovaling 35.7 241.5 277.2
S. Shohin 0.0 0.0 0.0
Sub-total 636.7 2,470.6 3,107.3
Badakhshan Vanj 18 312 330
Darvoz 0 167 167
Ishkoshim 34 258 292
Murgab 15 35 50
Rushon 14 262 276
Roshkala 0 661 661
Shugnon 54 600 654
Khorog 0 0 0
Sub-total 135 2,295 2,430
Total PRB 1,189.2 6,077.3 6,715.1

Note: There are no inter-farm and on-farm irrigation systems in the Baldzhuvansky and Shamsidin Shokhinsky Districts. The irrigated lands of Temurmalik district are managed by the Vose District of ALRI.

Reservoirs

The use of artificial and natural reservoirs and their maintenance in good technical condition for the basin are of increasing importance. We must make a reservation that the question is being raised about the study of large capacity reservoirs with a volume of 0.02 to 10 cubic km and located in such a way that they can possibly be used for the needs of hydropower and irrigation, or affect this kind of use. Therefore, such reservoirs as Tigrovaya Balka lakes (reserve), Karakul, Shur-Kul and Rangkul in the Murghab district of GBAO are not included in the intended list of reservoirs for study.

Currently, the basin has two reservoirs formed by blockages: Sarez Lake on the Bartang River, Yashil-Kul on the Gunt River. There are two small reservoirs related to irrigation with a volume of 20 to 30 million m3 – Muminobod and Selbur.

The Muminobod Reservoir, commissioned in 1958, is located on the Surkhak River and has a surface area of 7.2 km2 and capacity of 25 million m3. The height of the dam is 34 m. The Selbur Reservoir commissioned in 1961 on the Kyzyl-Su River covers a surface area of 2,55 km2 and has a capacity of 20 million m3. The dam is 1,040 m long with a maximum height of 132 m.

The number of waterworks with large reservoirs is projected to increase significantly in order to utilize the hydropower potential of the basin. The potential dam sites, most of which were planned for implementation in the next 15-20 years, and the existing ones are presented in the table below. Some of these dam sites are being developed, for example, the Lower Pyanj and the Sarez Lake.

Table 2: Potential Dam Sites in the Pyanj River Basin

Name and location Water level (m) Backwater (m) Total volume (km³) Net volume (km³) Reservoir area (km²) Comments
Lower Pyanj 0.0 0.0 0.0 0.0 0.0 redesigned
Dashti-Jum 1,055.0 300.0 17.6 10.2 135.0 potential
Granite Gate 1,570.0 215.0 1.3 0.03 0.0 potential
Rushan 2,060.0 295.0 5.5 4.1 71.0 potential

Pumping Stations

The basin is sub-divided into three water resource zones: (i) Nizhny (Lower) Pyanj; (ii) Kulyab (Kyzyl-Su, Yah-Su); and (iii) Badakhshan. The main sources of irrigation water in the basin are the Kyzyl-Su, Yakh-Su, Pyanj, Kulyabdarya and also smaller rivers.

Water for about 40% of the irrigated areas of the basin, is supplied using pumping stations (28% of pumping stations are state-owned, 12% have other ownership). There are 73 pumping stations in the basin, including: (i) Lower Pyanj WRZ, state owned – 22, non-state owned – 2; (ii) Kulyab WRZ, state owned – 46, non-state owned – 5; and (iii) Badakhshan WRZ, state owned – 10, non-state owned – 16.

The 1,000 ha of the existing 2,000 ha of irrigated land of the Jamoat “Ozodi” of the Jaikhun District is irrigated with water from the Pyanj River, supplied by a cascade of “Fayzobod Kala” pumping stations of the ALRI Pyanj Administration.

Table 3: Main Features of the Existing Pumping Stations

Water resource zone District Irrigated area (ha) Electricity consumed, (thousand kW/year) Number of pump stations Number of pump units Length of

pressure pipelines (m)

Total Including pumped irrigation
Lower Pyanj Dusti 0 0 0 0 0 0
Jaykhun 27,992 13,622 26,548 6 46 7,536
Pyanj 15,062 4,629 38,144 16 64 13,729
Sub-total 43,054 18,251 64,692 22 110 21,265
Kulyab Baljuvon 104 0 0 0 0 0
Vose 19,407 12,839 12,075 23 106 18,961
Dangara 10,418 1,161 5,897 3 8 820
Kulyab 8,350 1,333 2,020 4 19 26,055
Muminabad 2,902 973 1,039 3 11 8,500
Temurmalik 1,060 0 0 0 0 0
Farkhor 24,632 11,071 13,068 9 41 5,951
Hamadoni 16,430 0 0 0 0 0
Khovaling 2,659 1,412 414 4 26 3,000
S. Shohin 256 0 0 0 0 0
Sub-total 86,218 28,789 34,513 46 211 63,287
Badakhshan Vanj 2,545 0 0 0 0 0
Darvoz 882 0 0 0 0 0
Ishkoshim 4,472 0 0 0 0 0
Murgab 2,036 0 0 0 0 0
Rushon 2,024 100 0 2 2 456
Roshkala 2,846 0 0 0 0 0
Shugnon 3,507 70 0 2 2 211
Khorog 297 40 0 1 1 120
Sub-total 18,609 210 0 5 10 818
Total PRB 147,881 47,250 99,206 73 331 85,370

Drainage Network

The total length of the drainage network in the basin is 2,393.4 km, of which inter-farm – 663.7 km (28%) and intra-farm – 1,729.7 km (72%). The total drained area is 51,391 ha with a drainage network density of 20.2 m/ha.

Another important feature of the drainage network of the basin is that its entire drainage volume is discharged into the Kyzyl-Su, Yakh-Su, Kulyabdarya, Toir-Su Rivers. The “Tigrovaya Balka” drainage flows into the Pyanj River, but currently there is no information about its volume.

Some 82% of the total irrigated area in the Farharo-Chubek system is equipped with drainage. The specific density of the drainage network is 23.77 m/ha and the density of the irrigation network is 33.28 m/ha. Out of the total irrigated area of 38,842 ha, 94% of the soils are not salinized. There are, however, sites with sodium carbonate salinization covering about 461 ha, which require chemical treatment for reclamation.

Table 4: Length of Drainage Network

Water Resource Zone District Drainage Network (km)
Inter-farm On-farm Total
Lower Pyanj Jaykhun 46.1 92.5 138.6
Pyanj 71.6 162.0 233.6
Sub-total 117.7 254.5 372.2
Kulyab Baljuvon 0 0 0
Vose 86 420 506
Dangara 9 213 222
Kulyab 42 28 70
Muminabad 0 28 28
Temurmalik 0 0 0
Farkhor 147 274 421
Hamadoni 118 226 344
Khovaling 0 0 0
S. Shohin 0 0 0
Sub-total 402 1,189 1,591
Badakhshan Vanj 0 3 3
Darvoz 0 0 0
Ishkoshim 9 12 21
Murgab 0 4 4
Rushon 8 36 44
Roshkala 0 0 0
Shugnon 7 1 8
Khorog 0 0 0
Sub-total 24 56 80
Total PRB   543.7 1,499.5 2,043.2

Irrigated Land

  1. The irrigated systems in the basin are located mainly in the Kulyab and lower Pyanj water resource zones, where irrigated areas amounted to 170,142 ha in 2018. The table below presents the recent (2010-2018) expansion of irrigation in the basin.

Table 5: Expansion of Irrigated Land 2010 – 2018

Water resource zone Total area (ha) Irrigated area (ha)
2010 2011 2012 2013 2014 2015 2016 2017 2018
Lower Pyanj 308,401 15,062 61,533 61,491 63,014 63,017 15,062 15,062 15,062 65,315
Kulyab 1,202,534 85,254 85,251 85,227 85,531 85,608 85,617 85,582 85,568 86,218
Badakhshan 6,289,817 18,097 18,120 17,769 18,224 18,224 18,511 18,524 18,559 18,609
Total PRB 7,800,752 118,413 164,904 164,487 166,769 166,849 119,190 119,168 119,189 170,142

Due to the varying natural characteristics in water resource zones, irrigated land is distributed rather unevenly. Historically, the first irrigation systems were established at the alluvial plains along the Pyanj River (Karadumskii massif). In these systems, mainly gravity irrigation was practiced. The irrigated lands of the hilly zones located beyond these alluvial zones were developed in the Soviet period, as part of large programs for the expansion of agricultural production in the 1960-70s. However, these irrigation systems require pumping to deliver water, sometimes for several stages.

As can be seen from the table below, despite the development of new lands, the average area of available irrigated land has noticeably decreased by 2018 due to high population growth rates, even after some increase of the irrigated land. The most critical is the situation in the Kulyab and Badakhshan zones, where the irrigated land was 0.07-0.08 ha/person.

Table 6: Irrigated Land per Capita (2018)

Water resource zone Irrigated area (ha) Population (2018) Irrigated area (ha/person)
Lower Pyanj 43,054 246,500 0.17
Kulyab 86,218 1,170,800 0.07
Badakhshan 18,609 223,500 0.08
Total PRB 147,881 1,640,900 0.09

Land Resources for Expansion of Irrigated Agriculture

The size and distribution of the population in the basin is characterized by a high natural population growth, a positive balance of external migration, and a low mobility of the indigenous population. This explains why, in terms of employment, the basin is generally lagging compared to the rest of the country.[1] Therefore, the Government of Tajikistan places a high priority to the development of agriculture and specifically of new irrigated agricultural land in this region.

The main criteria for the selection of land for irrigation were the topography, soil properties, availability and distance to the water source, and socio-economic development. The availability of the arable land (394,160 ha) in the basin and a significant number of the working population create favorable conditions for intensification of agriculture by providing irrigation infrastructure. At present, irrigated lands are located mainly in the lower parts of basin and only a smaller part (recently developed) on the upper terraces. Because of this, the further development of irrigation would involve virgin and grazing lands located higher along the sides of these valleys, therefore, the area with pumped water supply would increase.

Some 15% of the irrigated areas in Tajikistan are concentrated in the Kulyab WRZ. The number of irrigated plots with an area up to 5 ha is 1,568, and 280 plots are with an area between 5 and 10 ha. Therefore, in the Kulyab WRZ, besides the main objective – irrigation of the Dangara Valley, irrigation of lands in the Baldzhuvan, Khovaling and Muminabad zones in planned. Development of irrigation in this zone is associated with the construction of the Baldzhuvnsky reservoir, and the second phase of the development of Karadum irrigation system is also planned.

Table 7: Irrigation Areas – Existing and Projected Growth by 2030

Name of district and

water resource zone

Total irrigable area (ha) Irrigated area in 2019 (ha) Potential for irrigation (ha) New areas

by 2030 (ha)

Jaikhun 39,804 27,992 6,458 34,450
Pyanj 19,444 15,062 1,586 16,648
Sub-total Lower-Pyanj zone 59,248 43,054 8,044 51,098
Baljuvon 2,680 104 2,680 2,784
Vose 64,982 19,407 1,022 20,429
Dangara 46,283 10,418 0 10,418
Kulyab 10,930 8,350 0 8,350
Muminabad 46,733 2,902 311 3,213
Temurmalik 13,961 1,060 1,518 2,578
Farkhor 39,128 24,632 3,442 28,074
Hamadoni 18,708 16,430 0 16,430
Khovaling 2,461 2,659 341 3,000
S. Shohin 1,070 256 140 396
Sub-total Kulyab zone 246,936 86,218 9,354 95,572
Vanj 3,058 2,545 571 3,116
Darvoz 2,065 882 160 1,042
Ishkoshim 5,040 4,472 268 4,740
Murgab 8,312 2,036 820 2,856
Rushon 4,722 2,024 1,000 3,024
Roshkala 2,000 2,846 110 2,956
Shugnon 5,190 3,504 199 3,703
Khorog 0 297 0 297
Sub-total Gorno-Badakhshan 30,387 18,609 3,128 21,737
Total PRB 336,571 147,881 20,526 168,407

Taking into account various scenarios of population growth, and to maintain the average irrigated land per person (0.09 ha/person) by 2030, it is necessary to develop 20,000-20,500 ha of and bring the total irrigation area to 168,500-169,000 ha. Given below are the indicators per person in the basin, taking into account the development of new irrigated lands by 2030, compared to 2018. In the basin, even with the development of new irrigated lands stipulated by the plans, there is a decrease in specific indicators per capita from 0.09 to 0.07 ha. This indicator is the lowest in the Kulyab WRZ of 0.06 ha per person.

Table 8: Irrigated Area per Person

Water resource zone Irrigated area in 2018

(ha/person)

Projected population by 2030 (thous.) Required area with population growth (ha) Area per capita with potential expiation by 2030 (ha/person)
Lower-Pyanj 0.17 341.6 58,072.0 0.14
Kulyab 0.07 1,554.9 108,843.0 0.06
Gorno-Badakhshan 0.08 251.6 20,128.0 0.08
Total PRB 0.09 2,148.3 193,347.0 0.07

Due to the projected high population growth, in particularly in the rural areas, the process of reducing the per capita area of available irrigated land will also continue. Vast financial resources will be required to develop new irrigated areas, including (i) rehabilitation and modernization of irrigation systems, (ii) procurement of equipment, and (iii) construction new hydraulic structures, canals, reservoirs, pumping stations and pipelines. The operation and maintenance of the new irrigation systems will also require an additional electric power.

Furthermore, it will be necessary to provide additional irrigation water. According to the “Plan for Development of Irrigated Lands of the Republic of Tajikistan,” an expansion of the irrigation area by 20,526 ha is planned in the basin. This will increase the water withdrawals from Pyanj River by 230,000 thousand m3/per annum. In total, water withdrawals amount to some 2,118,796 thousand m3. This emphasizes the need for efficient water application within the current and new irrigation schemes.

Irrigation Water Use and Future Demands

Reportedly, in 2018 the regional ALRI divisions provided water for an area of 147,881 ha. The total volume of water withdrawals for this period amounted to 1,750,080,000 m3, (planned water withdrawal), and 1,888,796, 000 m3 (actual water withdrawal). According to the revised norms for integrated use and protection of water resources of the basin, approved by the Ministry of Water Management of the Tajik Soviet Socialist Republic (SSR) on 02.29.1984, water standards range from 9,500 to 10,660 m3/ha. Thus, the total estimated regulatory water withdrawal for irrigation for the Pyanj Basin in 2030, taking into account the projected expansion of irrigated land, will amount to 1,735,599 million m3/year (see below).

Table 9: Regulatory Irrigation Water Requirements until 2030[2]

Water resource zone Normative

intake

(m3/ha)

2018 2030
Total irrigated

area (ha)

Regulatory

water intake

(million m3/year)

Total irrigated

Area (ha)

Normative water intake (million m3/year)
Lower-Pyanj 10,660 43,054 458,956 51,098 544,705
Kulyab 10,300 86,218 880,045 95,572 984,392
Badakhshan 9,500 18,609 176,785 21,737 206,502
Total PRB 147,881 1,515,786 168,407 1,735,599

Note: Using water conservation technologies can save up to 10% of irrigation water.

Considering that the total amount of water resources in the basin, taking into account all surface and underground water as well as reuse of drainage water, the required withdrawals appear to be much less that the available water resources in the basin.

Analysis of the retrospective data on use of water resources and the technical condition of water management systems explains the low efficiency of these systems, the inadequate water technology and services provided to agriculture (mainly irrigation), and in industrial and municipal sectors.

The weaknesses of irrigation systems operation and maintenance include, in the first place, inefficient water use at farm level. This calls for introduction of modern irrigation technology, rehabilitation and modernization of the existing I&D networks along with measures for land improvement, the lack of automation and remote control of water distribution, as well as application of institutional and financial improvements.

Furthermore, most of the irrigation networks are not lined, inter-farm and on-farm canals have extensive unlined sections and are not sufficiently equipped with water control and measuring devices. In many of the irrigation systems, only limited number of water intakes, main and distributor canals are meet the technical standards. Almost all irrigation systems have the following drawbacks:

  • Excessive length of the irrigation network, variable cross sections and slopes, often; as well as siltation and overgrowing vegetation in canals;
  • Numerous field delivery points, fragmentation of irrigated plots, incorrect configuration and insufficient leveling, lack of lining, which causes low efficiency and often, along with the lack of extension services in farms, leads to waste of water.

Based on the assessment of the current state of irrigation systems, and the use of land and water resources of the country, the main following directions for improving the technical conditions and operation of irrigation systems were identified:

  • Reconstruction and modernization of the existing irrigation systems, and augmentation of water supply; introduction of automation and remote control of water allocation and management and introduction of improved irrigation technology;
  • Improvement of soil condition of existing irrigated lands, rehabilitation of the existing drainage network and construction of new modern drainage systems on irrigated lands, land leveling, and other technologies aimed at improving the quality of irrigated land; and
  • Improvement of construction and maintenance practices, provision of maintenance services for the inter-farm network and structures, and optimization of on-farm water management and related extension services.
  1. For example, the unemployment rate in the GBAO is 2.5 times higher than the average in Tajikistan.
  2. Subject to expansion of irrigated land and the provision of a normative water withdrawals.