Mahakali Irrigation System – Stage I

Government of Nepal Ministry of Irrigation Department of Irrigation Irrigation and Water Resources Management Project (IWRMP)

Canal Operation Plan Draft Final Report

Prepared by

Desh Bhakta Mallik WME-MIS

April, 2016

Table of Contents of Canal Operation Plan

Chapter-1 Introduction 1.1 General Background 1.2 Background of the Existing Problems 1.3 Objective of Canal Operation 1.4 Scope of Canal Operation Plan 1.5 Organization of document Chapter-2 Physical System 2.1 Background of the Project 2.2 Inventory of Canal Structures 2.2.1 Main Canal 2.2.2 Branch Canal 2.2.3 Secondary Canal 2.2.4 Tertiary Canal 2.3 Climatic Resources 2.3.1 Climate 2.3.2 Rainfall 2.3.3 Temperature 2.3.4 Relative Humidity 2.3.5 Evaporation 2.3.5 Sunshine Hours 2.3.6 Wind Speed 2.4 Land Resources 2.4.1 Land and Soil Types 2.4.2 Percolation Losses 2.5 Cropping Pattern 2.6 Operational Status

Chapter-3 Irrigation Plan

3.1 Water Resources 3.2 Proposed Cropping Pattern 3.3 Soil Saturation Requirement 3.4 Land Soaking and Land Preparation Requirement 3.4 Conveyance Capacity and Irrigation Efficiency 3.5 Diversion Requirement 3.6 Water Balance 3.7 Water Allocation, Distribution and Scheduling 3.8 WUA Policy of Water Distribution

Chapter-4 Organization for Canal Operation Plan Management

4.1 Existing Organization 4.2 Procedures of Canal Operation and Communication 4.3 Proposed Personnel and Skill Required 4.4 Proposed Organization and Staff Scheduling

Chapter-5 Monitoring and Evaluation of Canal Operation

Chapter-1 Introduction

1.1 General Background

Mahakali Irrigation System is a large-scale Agency Managed Irrigation System of Terai. Command area of this system was developed in two stages. About 5 years ago, irrigation management of Mahakali Irrigation System, Stage -1 (MIS-I) has been transferred to WUA Regional Committee, under Irrigation Management Transfer (IMT) component (Component- B) of Irrigation and Water Resources Management Project (IWRMP) of Department of Irrigation (DoI). The WUA will operate and maintain the transferred system below main canal as per the legal transfer agreement guidelines. The responsibility of operation and maintenance of main canal remains with DoI, Mahakali, Pathraiya, Mohana Irrigation Management Division (MPMIMD).

The overall objective of this component is to improve service performance and service delivery of MIS-I. The Component-B is designed to address the problem in large public irrigation schemes (AMIS or agency –managed irrigation systems) of below –capacity performance, poor O&M, negligible cost recovery (below 5 percent on average) and inadequate maintenance funds.

The Component-B is to provide improved arrangements and instruments for operation and maintenance (O&M) to AMIS for empowering WUAs to operate, maintain and manage parts of the irrigation systems for their sustainability. Canal Operation Plan is such an instrument expected to help in improving the service performance and service delivery.

The Component-B aims to achieve : (i) improved physical performance of the MIS-I; (ii) reliable bulk water service delivery from main canal to off-taking branch and minor canals by DoI, MPMIMD, and (iii) efficient and equitable service delivery from branch and minor canals to tertiary canals, and from tertiary canals to field outlets by WUA.

Therefore, COP should focus on making bulk water service delivery from main canal to branch and minor canals reliable, and service delivery from branch and minor canals to tertiary canals, and from tertiary canals to field outlets efficient and equitable.

Basically canal operation is the process of releasing, conveying and dividing water in the canal system to ensure predetermined flows at prescribed times for specified durations at demarcated points of delivery. However, it should be reliable, safe, efficient and equitable. For making the water delivery reliable, safe, efficient and equitable, it should be well informed to WUA and farmers. It can be done through introducing water delivery schedule.

The water-delivery schedules are defined by the following characteristics:  Frequency (How often the water arrives?);  Rate (How much water flows per unit of time?);  Duration (How long is the flow rate delivered?);  Timeliness (Does the water arrive when the crop needs it or the farm can use it?).

The traditional canal operation is supply oriented in which the flow is determined by upstream supply source or inflow. However, it involves large water loss, because the water allocation and water delivery schedule are based on the water right and the supply does not reflect the actual crop water demands. The modernization irrigation calls for demand oriented canal operation, in which water delivery schedule is prepared based on crop water requirement. The demand oriented scheduling could save as much as 50% of water supply compared with supply oriented approach. However, this approach poses problems from the point of view of practical canal operation, because of flow variations and hence the operation requirements in the tertiary canals will be high. Also, frequent adjustment in check gate of main canal would be necessary to achieve the required performance. This approach provides flexibility to farmers in terms of time and volume of water, but the complexity of operation and burden of operator increase with the freedom of water use increases.

In IMT irrigation system, which is managed by WUA, water delivery schedule should be simple and user friendly. Supply oriented water delivery schedule is simple and user friendly, but water loss is very high. On other hand demand oriented approach is more efficient than supply driven approach, but the canal operation is complex. Therefore, water delivery schedules should be prepared first on the basis of supply oriented approach, and later they could be gradually modified based on the actual demand of crops, when farmers will be able to convey about their demand for irrigation water to WUA tertiary committee and the tertiary committee can communicate farmers’ demands to upper level WUA and eventually to MPMIMD, who is responsible for operation of main canal.

Water delivery schedule alone is not sufficient for improving the service performance of irrigation system. Water distribution procedures and regulations are equally important. In addition, organization and management of operation are also essential. Finally, implementation of canal operation plan, water measurement at strategic points (such as at border weir and bulk water delivery points) and monitoring and evaluation of canal operation process and the service delivery are also vital.

1.2 Background of the Existing Problems

In MIS-I water availability from Sarada Barrage is assured as per Indo-Nepal agreement 1996 AD. Here, the problem is mostly related to operation management and maintenance management of irrigation system. As far as the canal operation is concerned, supply oriented approach has been followed for years. MPMIMD requests Sarada Barrage Authority to release the requested discharge into the main canal. During monsoon season, about 12 cumecs of water is released. In case, for any reason such as excessive rainfall, the water demand in command area is reduced, MPMIMD requests Sarda Barrage Authority to decrease the discharge into main canal as requested. In this way, when the demand is decreased or increased, the supply from the barrage is adjusted as requested by MPMIMD. During dry season (winter and spring), the barrage authority releases more than assured discharge of 4.25 cumecs. In both monsoon and dry season when water is not demanded, barrage authority closes the flow into main canal as per request of MPMIMD. Decision on date of opening and closing of main canal is usually done by MPMIMD in consultation with WUA Central Committee.

The water guards distribute the water from main canal to branch and minor canals with their past experiences and in consultation with WUA. In monsoon season, water is delivered in all the branch and minors continuously. In dry season, day time water is distributed to all the

2 branch and minor canals of MIS-I and in the night all these branch and minor canals are closed and whole water is conveyed to MIS-II.

Although water availability in MIS is sufficient, tail end and remote farmers do not get their share of water. In winter, the tail end farmers complain that they do not get water in time. Head and middle farmers leave all the water when they do not need any more, which damages the crops. Water management practices are not followed. For example, Water delivery schedules are not prepared. Gauges are not painted on water measurement structures. Measurement of bulk water delivery from main canal to branch and minor canals are not done regularly. Control structures of main canal such as head regulators and cross regulators need repair and maintenance. Distribution of water to the tertiary canals is not equitable. Head and middle tertiary canals take more water than their share. In addition, illegal pipes have been inserted into canals to steal water. As a result, tail end tertiary canals do not get their share of water.

WUA Tertiary Committee is not active towards equitable distribution of water among farmers. Head and middle committees are not active because their tertiary canals get sufficient water and tail end committees are not active because they think their voice will not be heard. Also, regional and block committees do not assist and encourage them in operation and maintenance.

In this way, service performance and service delivery of MIS-I are poor and need improvements.

WUA Regional Committee and Blocks Chairpersons of MIS-I informed that:

 There is no rule of operating canal and distributing water to the tertiary canals.  There is no schedule of distributing water from outlets to the farmers’ plots.  When canal is in operation, farmers open the gate to take out maximum water flow in their tertiary canals.  Farmers cut tertiary and irrigate their plot. They do not bother to close the cut after irrigating the fields (in paddy season). Down reach farmers have to close such cuts to irrigate their plots.  Tail end farmers of distributary canals and longer branch and tertiary canals get water only when upstream farmers finished irrigation or they have to irrigate with small stream of residual water spending longer duration for irrigation, and  In case of longer tertiary canals, instead of taking water from assigned tertiary outlets, the farmers cut distributary and branch canals and insert pipe in the bank to take out water for irrigating their field.  Parcellary maps of tertiary outlets have not been prepared.

Some of the observations during field visit are –

 farmers put barriers in the canal to raise water level so that water can pass through their outlets,  The tertiary canals get silted quickly, so instead of cleaning them, the farmers insert unauthorized pipes and take water from higher order canals,  Siltation in distributary and minor canals has reduced their capacity

 Farmers have installed unauthorized gates in the canals and removed existing tertiary gates at their own will,  Cross-regulators of main canal is lowered to raise the water level to deliver water to some of the tertiary canals and minors, but escape regulators are hardly used when there is no demand of water and gates of distributary and minors have to be shut down, and  Some farmers grow lentils on canal banks

1.3 Objective of Canal Operation

General objective of canal operation is to deliver an irrigation service to farmers, which is reliable, predictable, efficient, equitable and timely.

Specific objectives of canal operation are: (i) To release and convey water into main canal for supplying assured bulk water delivery to branch and minor canals. (ii) To distribute the flow received in branch and minor canals to the tertiary canals equitably. (iii) To control water flow in the canal network for meeting water requirements of crops in order to achieve optimum production; water savings; safety of operation; and recovery of operating costs, (iv) To control water level in the canal in order to keep command of the service area through gravity, canal protection against deterioration, canal safety and flow control at off-takes, and (v) To control canal under variable flow conditions.

1.4 Scope of Canal Operation Plan

The canal operation plan aims to assist in conducting effective day to day operation of canals of an irrigation system, towards providing reliable, predictable, efficient and equitable irrigation service to beneficiary farmers.

General objective of preparing the canal operation plan for MIS Stage-I is to deliver improved irrigation service to water user farmers to their satisfaction, towards increasing yield of agricultural crops grown in the command area. And, the specific objective is to provide improved arrangements and instruments for ensuring reliable bulk water delivery from the main canal to branch and minor canals, and efficient and equitable water distribution to the lowest level canals (tertiary canals for MIS) of the system.

There are several advantages of having a canal operation plan for the whole irrigation system:

a) It will assist system operators in smooth operation of the irrigation system b) It will ensure equitable distribution of irrigation water to entire land and landowners located in the command area of the system. c) Farmers will know about allocation and distribution of irrigation water. So, they will be confident of getting water required for growing crops. d) Reliability of irrigation system will increase. e) For the farmers located at the tail-end of the irrigation system, it guarantees them the same level of service as the other groups. f) Overall efficiency and performance of service delivery of the irrigation system will increase.

The canal operation plan mainly includes the following:

 Description of irrigation system  Calculation of irrigation water requirement for farmers’ cropping pattern  Irrigation plan of operation  Procedure/process of implementation of the irrigation plan (actual distribution of water)  Monitoring and evaluation of the canal operation

1.5 Methodology and approach of preparing canal operation plan

Methodology and approach adopted include the following:

 Cropping pattern study  Calculation of irrigation water requirement and water balance study  Preparation of water delivery schedule based on supply-oriented approach in consultation with WUA  Description of water distribution procedures and regulations  Monitoring and evaluation approach

1.6 Organization of the document

This document consists of five chapters. Chapter 1 gives introduction of canal operation in MIS-I and about the canal operation plan. Chapter 2 provides description of the physical system of MIS-I. Chapter 3 contains inventory of canal structures, climatic resources, land resources and the cropping pattern of MIS-I. Chapter 3 gives irrigation plan of MIS-I, which includes proposed cropping pattern, water balance and water delivery schedules. Chapter 4 explains about procedures of water distribution and communication, and water distribution regulations. And, Chapter 5 gives monitoring and evaluation of canal operation process and irrigation service delivery.

Chapter-2 Physical System

2.1 Background of the Irrigation System

Mahakali Irrigation System (MIS) is located in Kanchanpur District, in Far-Western Development Region of Nepal. It gets its water supply from the River Mahakali through the Sarada Barrage, which was constructed in 1928 by the British Indian Government. This irrigation system was initially constructed in nineties by the Government of Nepal. By 1975, main canal and some major secondary were completed but not more than 3400 ha could be irrigated. In 1976, the Mahakali Irrigation Project (MIP) was identified by International Development Association. The Development Credit Agreement for the Mahakali Irrigation Project (Stage I) was signed on September 29, 1980, with an effective date of December 30, 1980. The project had a five-year implementation period, with a completion date of June 30, 1985. The project (Stage I) was completed in 1988. Financing agreement for Stage II of Mahakali Irrigation Project between Government of Nepal and International Development Association was signed on and made effective on 18 November 1988. The project (Stage II) was completed in June1997.

Total command area of the MIS is 11600 ha. The command area is separated into two parts by the Shuklaphanta Wildlife Reserve Forest (Figure 1). The upper part of command area is named as MIS Stage-I and the lower part of the command area (downstream of the Shuklaphanta Wildlife Reserve Forest) is named as MIS Stage-II.

Figure 1 : Location Map of Mahakali Irrigation System

The main canal off-takes from eastern bank of the barrage. It runs eastward through Mahendranagar upto Ghorsuwa Escape and from there it goes southward through Daiji and Shuklaphanta Wildlife Reserve Forest upto Kalikich (Beldandi). The main canal bifurcates into two main branch canals at Kalikich, namely - the Shivnagar main branch canal and Belauri main branch canal (M3 Canal). Total length of main canal upto Kalikich is about 36 Km and its design discharge is 28.35 m3/s (1000 cusecs).

The Department of Irrigation supplies bulk water delivery from main canal to branch and minor canals. There are 11 branch and minor canals in MIS Stage-I to convey irrigation water to tertiary canals for distribution among farmers’ fields. These are Gudda minor, Bhujela

6 distributary, Basantpur minor, Majhgaon minor, Mahendranagar distributary, Bhagatpur minor, Ultakham distributary, Chunariya minor, Suda minor, Sisaiya minor and Daiji minor. In addition, there are 25 sub-minor and tertiary canals, which off-take direct from the main canal.

Figure 2 Branch and minor canals of MIS-I

In MIS Stage-II area, bulk water supply is delivered to branch and minors through Shivnagar and Belauri main branch canals. The Shivnagar main branch canal is about 21 Km long. It runs westward upto Jhilmila, then to south-eastward upto Sadakghat and finally northward upto Shivnagar. Its design capacity is 3.49 m3/s and the command area is 3400 ha. The Shivnagar main branch canal delivers water to eight branch and minor canals, which convey it to tertiary canals of block 5 and 6 for distribution among farmers’ fields. These are Kamari branch, Khairighat branch, Imiliya minor, Baibaha branch, Jhilmila minor, Bhuda minor, Bhuda-Gauri minor and Gaurigaun minor. In addition, there are 48 tertiary canals, which off- take direct from the main canal and the Shivnagar main branch canal.

The Belauri main branch canal (M3 Canal) is about 16 Km. It runs south-eastwards upto Singhpur. Its design capacity is 3.53 m3/s and the command area is 3100 ha. The Belauri main branch canal delivers water to eleven branch and minor canals, which convey it to tertiary canals of block 7 and 8 for distribution among farmers’ fields. These are Beldandi branch, Beldandi minor, Dhakka minor, Salghari branch, Salghari minor, Pachoi branch, Kunda minor, Singhpur minor, Syali-A minor, Syali-Y minor and Belauri branch. In addition, there are 4 tertiary canals, which off-take direct from the Belauri main branch canal. The command area of MIS-I is divided into 5 blocks A –E, and that of MIS-II is divided into 4 blocks 5 – 8. Block-wise list of branch and minor canals MIS-I and MIS-II is given in Table 1.

Table 1 – Block wise group of branch and minor canals

MIS Stage Block Branch and minor canals

I A Gudda minor and Bhujela distributary B Basantpur minor, Majhgaon minor and Mahendranagar distributary C Bhagatpur minor and Ultakham distributary D Chunariya minor, Suda minor and Sisaiya minor E Daiji minor II 5 Jhilmila minor, Bhuda minor, Bhuda-Gauri minor and Gaurigaun minor 6 Kamari branch, Khairighat branch, Imiliya minor, Baibaha branch 7 Beldandi branch, Beldandi minor, Dhakka minor, Salghari branch, Salghari minor, Pachoi branch and Khajuwa minor 8 Kunda minor, Singhpur minor, Syali-A minor, Syali-Y minor and Belauri branch

Table 2 Details of branch and minor canals of MIS-I

S. Branch and Minor Canals Chainage of Length Design Command Area No. Main Canal (Km) Discharge (ha) (Km) (litre/sec) 1 Gadda minor 0+915 1.805 240 120 2 Bhujela distributary 2+085 4.435 1550 926 3 Basantpur minor 2+519 2.100 385 182 4 Majhgaon minor 3+736 4.880 431 294 5 Mahendranagar distributary 5+172 5.895 1064 582 6 Bhagatpur minor 8+970 2.012 260 140 7 Ultakham distributary 9+524 7.622 1943 1064 8 Chunariya minor 11+460 0.523 124 68 9 Suda minor 12+477 4.060 1170 617 10 Sisaiya minor 14+879 4.156 610 292 11 Daiji minor 17+009 2.885 320 300

Table 3 Details of Sub-minor and Tertiary canals off-taken from main canal of MIS-I

S. Branch and Minor Canals Chainage of Design Command Area No. Main Canal Discharge (ha) (Km) (litre/sec) 1 Main 2/A 1+205 0.03 4 2 Main 2/1 1+405 0.13 35 3 Main 2/B 1+625 0.03 4 4 Main 2/C 1+625 0.03 4 5 Main 2/D 1+630 0.03 4 6 Main 2/E 2+085 0.03 4

7 Main 2/F 2+090 0.03 4 8 Main 2/G 2+095 0.03 4 9 Main 2/H 3+555 0.03 4 10 Main 2/J 3+875 0.03 4 11 Main 2/K 4+130 0.03 4 12 Main 2/2 4+173 0.06 20.2 13 Main 2/3 4+572 0.06 36.7 14 Main 2/4 4+950 0.08 32.1 15 Main 2/4A 4+952 0.02 8.2 16 Main 3/2 10+755 0.03 4 17 Main 3/1 11+005 0.03 4 18 Main 3/A 11+005 0.03 4 19 Main 3/B 11+460 0.03 4 20 Main 3/C 12+477 0.03 4 21 SI 1/1 13+715 0.03 28 21 SI 1/2 13+741 0.03 20 23 SI 1/3 13+741 0.03 20 24 DJR 1/1A 16+890 0.03 25 DJR 1/1B 16+890 0.03

2.2 Inventory of Canal Structures (MIS-I)

2.2.1 Main Canal

(A) Length of Main Canal upto Balama Syphon (MIS Stage-I) - 20.054 Km (B) Inventory of Structures (MIS-I)

Table 4 Inventory of structures in main canal

S. No. Structure No. 1 Weir 2 2 Branch/Minor Head Regulator 11 3 Sub-minor off-take Head Regulator 6 4 Tertiary off-take Head Regulator 18 5 Cross Regulator 7 6 Escape 4 7 Bridge 13 8 Drop 3 9 Cross-drainage 11 10 Canal Syphon 5 11 Super passage 3

2.2.2 Branch and Minor Canals

(A) Length of Branch and Minor Canals (MIS Stage-I) - 37.440 Km (B) Inventory of Structures

Table 5 Inventory of structures in branch and mionor canals

S. Branch/Minor Secondary Tertiary Cross Check/ Side Tail Bridge/ No. Head Head Regulator Drop Escape Escape Culvert Regulator Regulator 1 Gadda Minor 2 1 2 Bhujela 4 12 3 4 1 Distributary 3 Basantpur Minor 5 3 1 4 Majhgaon Minor 13 9 1 5 Mahendranagar 1 16 2 6 1 Dist. 6 Bhagatpur Minor 5 4 1 7 Ultakham Dist. 1 23 14 3 8 Chunariya Minor 3 1 1 9 Suda Minor 1 16 2 8 1 1 10 Sisaiya Minor 11 8 2 11 Daiji Minor 7 1 1 3 Total 7 113 9 57 9 4 4

2.2.3 Secondary Canals

(A) Length of Secondary Canals (MIS Stage-I) – 16.469 Km (B) Inventory of Structures

Table 6 Inventory of structures in secondary canals

S. Secondary Canal Parent Canal Tertiary Cross Check/ Side Tail No. Head Regulator Drop Escape Escape Regulator 1 BJ1/R1 Bhujela 2 1 Distributary 2 BJ3/R1 Bhujela 5 2 1 Distributary 3 Bankatti, BK Bhujela 10 4 1 Distributary 4 Pipariya, PI Bhujela 7 1 1 1 Distributary 5 MN1/L1 Mahendranagar 4 2 1 Dist. 6 UL5/L1 Ultakham Dist. 18 3 2 7 UL9/R1 Ultakham Dist. 2 8 SU4/L1 Suda Minor 6 5 1 Total 54 1 17 4 4

2.2.4 Tertiary Canals

Total number of tertiary canals – 201

2.3 Climatic Resources

2.3.1 Climate

The climate in the Kanchanpur district is sub-tropical characterized with two distinct seasons namely wet (rainy) season from June to September and dry season from October to May. Average monthly temperatures range from 16.35ºC in January to 31.5ºC in May.

2.3.2 Rainfall

More than 80% of the total annual rainfall in command area occurs from June to September. Rainfall during the dry season occurs in occasional showers. Average monthly rainfall data for Mahendranagar Station have been taken from FAO / CLIMWAT 2.0 for CROPWAT and are given in Table 7.

Table 7 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Average Monthly 25 20 20 14 33 198 294 258 183 40 8 9 1102 Rainfall (mm)

2.3.3 Temperature

Temperature data for Mahendranagar Station have been taken from FAO / CLIMWAT 2.0 for CROPWAT, and are given in Table 8. The table gives average monthly minimum and maximum temperatures.

Table 8 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Minimum Temperature 10.3 11.3 16.4 20.7 23.7 25.2 25.2 25.2 25.2 20.4 14.1 10.2 (ºC) Maximum Temperature 22.4 25.8 31.8 38 39.3 37.3 33.4 32.8 32.7 31.5 26.5 22.6 (ºC)

2.3.4 Relative Humidity

Relative humidity expresses the degree of saturation of the air, as the ratio between the amount of water the ambient air actually holds and the maximum amount it could hold at the same temperature. It fluctuates between a maximum near the sunrise and a minimum around early afternoon, in accordance with temperature variations. It is expressed as a percentage (%). The relative humidity ranges from 34-58% during the dry season and 62-79% during the wet period. Relative humidity data for Mahedranagar Station have been taken from FAO / CLIMWAT 2.0 for CROPWAT, and are given in Table 9.

Table 9 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Relative Humidity 55 52 46 34 38 62 79 79 70 59 58 55 (%)

2.3.5 Evaporation

Monthly open water evaporation estimates (Eo), in mm per day, for Mahendranagar station are taken from PDSP (1990) and are given in Table 10.

Table 10 Station : Mahendranagar Index No. 105 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average Eo 2.27 3.39 4.79 6.92 8.00 6.99 5.25 5.17 5.06 4.42 3.42 2.54 4.85 (mm per day)

2.3.6 Sunshine Hours

The daily sunshine hours data for Mahendranagar Station have been taken from FAO / CLIMWAT 2.0 for CROPWAT and are given in Table 11.

Table 11 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Sunshine 7.5 8.2 8.7 8.9 8.2 5.4 4.3 4.7 5.7 7.0 7.9 7.6 (hours)

2.3.7 Wind Speed

The mean wind speed data for Mahendranagar Station have been taken from FAO / CLIMWAT 2.0 for CROPWAT and are given in Table 12.

Table 12 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Wind Speed 86 104 121 147 147 130 121 104 95 86 78 78 (Km per day)

2.3.8 ETo (Reference Evapo-Transpiration)

ETo calculation has been done by CROPWAT 8.0.

Table 13 ETo Calculation Result

Country : Location 45 Station : Mahendranagar Altitude : 176 m Latitude : 29.03 °N Longitude : 80.21 °E Month Min Max Humidity Wind Sun Rad ETo Temp Temp °C °C % km/day hours MJ/m²/day mm/day January 10.3 22.4 55 86 7.5 13.4 2.13 February 11.3 25.8 52 104 8.2 16.4 2.94 March 16.4 31.8 46 121 8.7 19.7 4.37 April 20.7 38 34 147 8.9 22.1 6.2 May 23.7 39.3 38 147 8.2 22.2 6.61

June 25.2 37.3 62 130 5.4 18.2 5.2 July 25.2 33.4 79 121 4.3 16.4 4.09 August 25.2 32.8 79 104 4.7 16.3 3.88 September 25.2 32.7 70 95 5.7 16.3 3.93 October 20.4 31.5 59 86 7 15.6 3.58 November 14.1 26.5 58 78 7.9 14.3 2.63 December 10.2 22.6 55 78 7.6 12.7 2.02

Average 19 31.2 57 108 7 17 3.96

2.4 Land Resources

2.4.1 Land and Soil Types

The land is flat and forms a gently inclined plain from north to south, with an average land slope of about 3%. In the command area, the soils are alluvial and fall into two main types: (i) yellowish and grey brown soils, developed under forest cover, coarse to moderately coarse textured sandy loam to loam and well drained; and (ii) deep alluvial soils consisting mainly of medium to moderately fine textured clay to silty loams, less permeably and poor drained.

2.4.2 Percolation Losses

The percolation and seepage losses depend on the type of soil. They will be low in very heavy, well-puddled clay soils and high in the case of sandy soils. The percolation and seepage losses vary between 4 and 8 mm/day. FAO (1986) has suggested percolation losses value as follows:

For heavy clay: PERC = 4 mm/day For sandy soils: PERC = 8 mm/day On average: PERC = 6 mm/day

2.5 Cropping Pattern

In MIS, Irrigation Management Division of Department of Irrigation and Water Users’ Association have no authority over the cropping pattern adopted by the farmers. In MIS-I, paddy is the principal crop of wet season (monsoon) and wheat is the principal crop of dry season (winter). Spring paddy is grown on some parts of command area. Aryal and Sharma (1992) mentioned that about 100% of the area during Kharif (wet season) and 92% of area during winter was cropped in MIS-I, and the total cropping intensity was 192.5%, exceeding the staff appraisal report target of 165%. Besides principal crops, other crops grown in MIS-I are maize, rape-seed and vegetables. A study was conducted in the command area of MIS-I in February 2016 to know about the cropping pattern and cropping intensity. Results of the studies are given below:

(a) Cropping pattern [Paddy] – [Wheat, mustard, lentil, vegetables and bursim grass] – [Spring paddy]

(b) Cropping Intensity Monsoon - [Paddy (95%)], Total – 95% Winter - [Wheat (91.1%), mustard (2.9%), lentil (2.9%), vegetables (2.7%) and bursim grass (0.4%)], Total – 100% Spring - [Spring Paddy] (5%)

Thus, annual cropping intensity is reported to be 200%. Date of sowing, transplantation and harvesting, and the cropped area are given in Table 14.

Table 14

Crops Date of sowing Date of transplantation Date of harvesting Cropped Initial Final Initial Final Initial Final area Monsoon paddy 21 May 25 June 20 June 25 July 17 October 21 Nov. 95% Wheat 10 Nov. 25 Nov. 19 March 03 April 91% Pulses 10 Nov. 27 Feb. 2.9% Mustard 10 Nov. 19 March 2.9% Vegetables 10 Nov. 12 Feb 2.9% Spring paddy 23 Feb 25 March 22 July 5%

2.6 Operational Status

(a) Main Canal: Main canal is operational up to the end of canal at Kalikich (Beldandi). Canal is silted and desilting is started by the contractor. Head regulator and cross regulator gates need to be repaired and maintained so that when head regulator gate is closed, no water should leak through it. Full supply level mark and Water level gauge are not painted. Calibration of some measuring structures is to be done.

(b) Branch and minor Canals:

All the branch and minor can supply water upto the tail end of the canals. Canals are silted. Full supply level mark and Water level gauge are not painted. Illegal pipes in branch and minor canals are reported.

Most of the tertiary canals are operational state. Few tertiary canals should be rehabilitated. In most of tertiary canals, the farmers clean the silt of the canals. Usually turnout gates are in good condition with few exceptions.

Chapter-3 Irrigation Plan

3.1 Water Resources

In MIS water supply from source is assured for both wet and dry season under Mahakali Treaty (1996) between Nepal and India. According to this treaty, Nepal shall have the right to a supply of 28.35m3/s (1000 cusecs) of water from the Sarada Barrage in the wet season (i.e. from 15th May to 15th October) and 4.25m3/s (150 cusecs) in the dry season (i.e. from 16th October to 14th May).

However, hydrograph of average flow in main canal measured at border weir (Figure 3) shows that discharge released from barrage is much less than the designed discharge during monsoon season, but usually more than the assured discharge 4.25m3/s (150 cusecs) in dry season.

Figure 3 Quarter-Monthly hydrograph of flow in main canal measured at border weir

3.2 Proposed Cropping Pattern

In MIS-I command area, cropping intensities during monsoon and winter season are almost 100%. In spring season, spring paddy is grown in small pockets of command area only. There are two reasons: (1) Water requirement is higher for spring paddy than the summer paddy and water available in the canal is less, and (2) Due to residual moisture in paddy field, wheat is sown late and so it is harvested late. As a result, transplantation of spring paddy becomes late and therefore the land is occupied at the time when transplantation of monsoon paddy is to be started. Due to late transplantation of spring paddy, on such land monsoon paddy is planted

15 around last week of July only. That is why farmers are not willing to grow spring paddy and there is very less possibility of change in existing cropping pattern.

3.3 Soil Saturation Requirement

Soil saturation requirement (Sn) is calculated by equation ; Sn = [Sc-(Mc*Bd)]* Drz/100

Where, Sn = Soil saturation requirement, in mm Sc = Soil saturation capacity, in % Mc = Soil residual moisture content, in% Bd = Bulk density of soil, in gm/cc Drz = Depth of root zone, in mm

Mc for wet season (preeeded by dry months) = Pwp Mc for dry season (preceeded by rainy months) = (Fc+Pwp)/2

Where, Fc = Soil Field Capacity, in % Pwp = Permanent Wilting Capacity, in %

Calculation of Soil saturation requirement for dry and wet season is given in Table 15.

Table 15 Soil Field Permanent Available Bulk Depth Soil residual Saturation Soil saturation Texture capacity wilting Water density of root Mc in % capacity requirement Sn Fc% point =0.1(Fc- gm/cc zone (total pore mm Pwp% Pwp) Drz in space) in mm/cm mm % Dry Wet Dry Wet season Season season Season Loam 31 14 1.7 1.4 300 22.5 14 47 46.50 82.20 Silty 40 20 2 1.3 300 30 20 51 36.00 75.00 Loam Sandy 21 9 1.2 1.5 300 15 9 43 61.50 88.50 loam Average 1.63 48 81.9 Say 82

Considering the equal contribution of all different three types of soil in the command area, the value of saturation requirement for dry season crop especially spring paddy calculated is 48 mm and for monsoon as well as early paddy is 91 mm as shown in Table 15.

3.4 Land Soaking and Land Preparation Requirement

For transplanting of paddy, Land soaking and Land preparation requirement such as ploughing, harrowing and supplying of water should be carried out in paddy fields to soften the soil. The necessary water to meet this requirement is called puddling requirement and depends on soil depth, soil porosity and residual soil moisture. In addition to this 60 mm of standing water depth is required for crop development. The total depth of water required for

16 land soaking and land preparation requirement is evaluated considering crop development irrigation at 10 days interval as follows:

Soil saturation requirement = 82 mm wet season crop Soil saturation requirement = 48 mm dry season crop Standing water depth = 60 mm Percolation rate (2.5 mm/day) = 25 mm wet season crop Percolation rate (3.5 mm/day) = 35 mm dry season crop Evaporation (4.3 mm/day) = 43 mm

Land preparation and land soaking requirement = 82+60+25+43 = 210 mm wet season crop Land preparation and land soaking requirement = 48+60+35+43 = 186 mm dry season crop

3.5 Conveyance Capacity and Irrigation Efficiency

From FAO 24 : Crop Water Requirement, Table 37 p.80,  Conveyance efficiency during wet season (for continuous flow), Ec (wet) = 0.9  Conveyance efficiency during dry season (for rotational flow), Ec (dry) = 0.8  Field canal efficiency (for block larger than 20 ha), Eb = 0.8  Field application efficiency (for surface methods and medium soil), Ea = 0.7

Overall Irrigation efficiency, Ei (wet) = Ea*Eb*Ec (wet) = 0.7*0.8*0.9 = 0.50 Overall Irrigation efficiency, Ei (dry) = Ea*Eb*Ec (dry) = 0.7*0.8*0.8 = 0.45

3.6 Diversion Requirement

Irrigation Diversion Requirement (IDR) is calculated by the equation :

IDR = Crop Evapo-transpiration (ETc) + Deep Percolation + Conveyance, distribution and application loss – Effective Rain

Irrigation Diversion Requirement for MIS-I has been calculated by FAO CROPWAT 8.0. For calculation of ETo, climate and rainfall data have been taken from FAO CLIMWAT 2.0 for CROPWAT for Mahendranagar Station (Location No. 45). Soil type adopted is medium type. Cropping pattern data are collected from field.

Irrigation Diversion Requirement for MIS-I calculated by FAO CROPWAT is given in Table 16.

Table 16 : Irrigation Diversion Requirement for MIS-I calculated by FAO CROPWAT

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Precipitation deficit 1. Wheat 1 55.8 71.9 31.3 0 0 0 0 0 0 0 13.7 26.5 2. Wheat 2 48.6 78 68.8 0 0 0 0 0 0 0 6.7 16.7 3. Wheat 3 42.7 78 89.7 3.7 0 0 0 0 0 0 3.7 13.8 4. Pulses 57.5 48.1 0 0 0 0 0 0 0 0 19.1 45 5. Mustard 55.8 71.9 31.3 0 0 0 0 0 0 0 13.7 26.5 6. Small Vegetables 50.5 26 0 0 0 0 0 0 0 0 35.2 50 7. Rice1 0 0 0 0 48.7 118.5 0 0 5.5 39.8 0 0 8. Rice2 0 0 0 0 0 154.1 0 0 6.8 73.1 0 0 9. Rice3 0 0 0 0 0 55.4 98 0 6.9 90.9 16.5 0 10. Rice4 0 0 0 0 0 0 198.3 0 6.9 94.6 58.2 0 11. Rice5 0 0 324.9 192.9 210.2 31.9 8.4 0 0 0 0 0

Net scheme irr.req. in mm/day 1.6 2.6 2.3 0.3 0.7 3 1.8 0 0.2 2.3 0.7 0.7 in mm/month 50.4 73.2 71.1 10.4 20.3 90.9 54.6 0 6.2 71.1 21.5 21.7 in l/s/h 0.19 0.3 0.27 0.04 0.08 0.35 0.2 0 0.02 0.27 0.08 0.08

Irrigated area 100 100 99 26 25 90 50 0 95 95 145 100 (% of total area)

Irr.req. for actual area 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 (l/s/h)

Table 17: Irrigation Requirement Calculation for Branch and Minors of MIS-I

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Remarks Gadda minor Irrigated Area 120 120 120 120 120 120 120 120 120 120 120 120 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha Gross scheme 61067.5 87091.2 86780 46656 96422.4 121306 131777 0 9331.2 89994.2 18662.4 25713 irrigation requirement (m3) Bhujela Distributary Irrigated Area 926 926 926 926 926 926 926 926 926 926 926 926 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha Gross scheme 471238 672054 669654 360029 744060 936075 1016881 0 72005.8 694456 144012 198416 irrigation requirement (m3) Basantpur minor Irrigated Area 182 182 182 182 182 182 182 182 182 182 182 182 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha Gross scheme 92619.1 132088 131617 70762 146241 183980 199862 0 14152.3 136491 28304.6 38998 irrigation requirement (m3) Majhgaon minor Irrigated Area 294 294 294 294 294 294 294 294 294 294 294 294 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha

Gross scheme 149615 213373 212611 114307 236235 297199 322854 0 22861.4 220486 45722.9 62996 irrigation requirement (m3) Mahendranagar dist. Irrigated Area 582 582 582 582 582 582 582 582 582 582 582 582 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha Gross scheme 296177 422392 420884 226282 467649 588332 639120 0 45256.3 436472 90512.6 124706 irrigation requirement (m3) Bhagatpur minor Irrigated Area 140 140 140 140 140 140 140 140 140 140 140 140 (ha) Irr.req. for actual 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 area l/s/ha Gross scheme 71245.4 101606 101244 54432 112493 141523 153740 0 10886.4 104993 21772.8 29998 irrigation requirement (m3)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ultakham Distributary Irrigated Area (ha) 1064 1064 1064 1064 1064 1064 1064 1064 1064 1064 1064 1064 Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Gross scheme irrigation 541465 772209 769451 413683 854945 1075576 1168425 0 82736.6 797949 165473 227985 requirement (m3) Chunariya minor Irrigated Area (ha) 68 68 68 68 68 68 68 68 68 68 68 68

Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Gross scheme irrigation 34604.9 49351.7 49175 26438 54639.4 68739.8 74673.8 0 5287.68 50996.7 10575.4 14570 requirement (m3) Suda minor Irrigated Area (ha) 617 617 617 617 617 617 617 617 617 617 617 617 Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Gross scheme irrigation 313989 447794 446195 239890 495772 623713 677555 0 47977.9 462720 95955.8 132206 requirement (m3) Sisaiya minor Irrigated Area (ha) 292 292 292 292 292 292 292 292 292 292 292 292 Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Gross scheme irrigation 148598 211922 211165 113530 234628 295177 320658 0 22705.9 218986 45411.8 62567 requirement (m3) Daiji minor Irrigated Area (ha) 300 300 300 300 300 300 300 300 300 300 300 300 Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Gross scheme irrigation 152669 217728 216950 116640 241056 303264 329443 0 23328 224986 46656 64282 requirement (m3)

Table 18 : Water Balance Calculations

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Irrigation Requirement Irrigated Area (ha) 4585 4585 4585 4585 4585 4585 4585 4585 4585 4585 4585 4585 Irr.req. for actual area l/s/ha 0.19 0.3 0.27 0.15 0.3 0.39 0.41 0 0.03 0.28 0.06 0.08 Net irrigation 2333288 3327610 3315725 1782648 3684139 4634885 5034990 0 356529.6 3438530 713059 982437 requirement (m3) Irrigation efficiency of 0.45 0.45 0.45 0.45 0.45 0.5 0.5 0.5 0.5 0.5 0.45 0.45 the canal system (%) Gross Irrigation 5185085 7394688 7368278 3961440 8186976 9269770 10069980 0 713059.2 6877060 1584576 2183194 Requirement (m3)

Water Availability Flow Available in Main 4.25 4.25 4.25 4.25 4.25 8.097 8.097 8.097 8.097 8.097 4.25 Canal (m3/sec) Flow share of Stage I 10.5 10.5 10.5 10.5 10.5 24 24 24 24 24 10.5 (hr/day) Irrigation efficiency of 0.45 0.45 0.45 0.45 0.45 0.5 0.5 0.5 0.5 0.5 0.45 0.45 the canal system (%) Water Available in main 4980150 4498200 4980150 4819500 4980150 20987424 21687005 21687005 20987424 21687005 0 4980150 canal for Stage I (m3)

Water Balance Gross Irrigation 5185085 7394688 7368278 3961440 8186976 9269770 10069980 0 713059.2 6877060 1584576 2183194 Requirement (m3) Water Available in main 4980150 4498200 4980150 4819500 4980150 20987424 21687005 21687005 20987424 21687005 0 4980150 canal for Stage I (m3) Monthly Water -204935 - -2388128 858060 - 11717654 11617024 21687005 20274365 14809945 - 2796956 Balance 2896488 3206826 1584576

3.7 Water Balance

Water balance calculations for MIS-I is given in Table 18. Here, it means comparing amount of water available from the irrigation system with irrigation requirement for the crops to assess surplus and deficit of water. This calculation helps in choosing technical and management options for adjusting the supply and the demand. It is particularly helpful in case of deficit of water situation.

In the water balance calculations for MIS-I, water available is in deficit for five months, namely January, February, March, May and November. The deficit seen in November is due to closure of main canal. This deficit is fulfilled from the water stored in the root zone upto the month of October. Similarly, the deficit of January and some part of deficit of February also can be fulfilled from the water stored in root zone in the month of December. However, deficit of remaining part of February, March and May can be addressed as follows:

(a) By reducing the cropped area of spring paddy, or (b) By distributing the available water to all farmers equitably, thereby proportionately distributing among them the risk of yield reduction under water stress condition.

Option (a) is not practical, because spring paddy is grown only on small portion of command area on one hand, and Government of Nepal, Ministry of Agriculture has started special programme to promote Spring paddy cultivation in Terai this year, in order to cope with the problem of importing rice. Therefore, Option (b) should be used to address the water deficit of February, March and May.

3.8 Water Allocation, Distribution and Scheduling

3.8.1 From Main Canal to Branch and Minor Canals

The main canal supplies bulk water delivery for MIS-I to WUA through eleven branch and minor canals. The design discharge and command area of these canals are given in Table 19.

Table 19 S. Branch and Minor Canals Design Discharge Command Area No. (litre/sec) (ha) 1 Gadda minor 240 120 2 Bhujela distributary 1550 926 3 Basantpur minor 385 182 4 Majhgaon minor 431 294 5 Mahendranagar distributary 1064 582 6 Bhagatpur minor 260 140 7 Ultakham distributary 1943 1064 8 Chunariya minor 124 68 9 Suda minor 1170 617 10 Sisaiya minor 610 292 11 Daiji minor 320 300 Total 8097

(a) Water availability for MIS-I

As per Mahakali treaty (1996), Nepal has right to get 28.35 cumecs supply during wet season and 4.25 cumecs supply during dry season from Sarada barrage. Thus, water available from the barrage during dry season is about 15% of the wet season right of water supply. However, full wet season discharge 28.35 cumecs is not required during wet season as the cumulative design discharge during wet season for MIS-I and MIS-II branch, minor and direct off-taking sub-minor and tertiary canals is about 17 cumecs, which is about 60% of the full discharge 28.35 cumecs. The command area of MIS-I is fully developed, while in MIS-II many tertiary canals are not constructed. That is why, less than full discharge requirement for MIS-I and MIS-II is usually released into the main canal in wet season. Figure 1 shows that average discharge during wet season that could be available reliably is about 12 cumecs, which can be increased to 17 cumecs.

During dry season, the discharge available in main canal is usually more than the assured discharge 4.25 cumecs. But the assured discharge 4.25 cumecs should be taken as reliable discharge. Since 4.25 cumecs is very less in comparison to main canal capacity, 24 hours time period (each day) of supply of this discharge is distributed for MIS-I and MIS-II area in proportion of their command area. Thus dry season discharge 4.25 cumecs is available for 10.50 hours for MIS-I.

(b) Water requirement for MIS-I canal system

The MIS is designed for continuous supply of design discharge in main, branch, minor and tertiary canals during wet season. So, all these canals should be run continuously with full supply discharge as per design throughout base period. In case demand for irrigation is reduced due to rainfall in the command area, the supply can be adjusted (reduced or cut) accordingly. Therefore, discharge requirement accounting should be done as per cumulative design discharge of the canals. Accordingly, the cumulative discharge requirement during wet season for MIS-I branch, minor and other smaller canals is a continuous discharge of about 8 cumecs.

During dry season, when supply from the barrage is less, branch and minor canals should be grouped and discharge requirement should be accounted as per cumulative design discharge of the canals in the group. Cumulative discharge of branch and minor canals is about 8 cumecs and the dry season discharge reliably available is 4.25 cumecs, about half of the cumulative discharge of branch and minor canals of MIS-I.

During wet season, supply in main canal is sufficient to feed cumulative discharge of about 8 cumecs continuously. It means all the branch and minor canals can receive their design discharge continuously from the main canal.

During dry season, that is during winter and spring season, assured supply in main canal is 4.25 cumecs, which is about half of the cumulative design discharge of branch and minor canals of MIS-I. So, the branch and minor canals of MIS-I have been divided into two groups with almost equal cumulative discharges. Each group shall alternatively receive water for 3.5 days a week, to match demand and supply.

(d) Water delivery schedule for Wet season (monsoon)

All the branch and minor canals of MIS-I shall get bulk water delivery equal to their design discharges all the seven days of a week (day and night) during wet season on continuous basis. There will be no rotation among branch and minor canals that off-take from main canal. Water delivery schedule from main canal to branch and minor canals of MIS-I for monsoon season is given in Table 20.

Table 20

S. Branch and minor canals Discharge Sun Mon Tue Wed Thu Fri Sat No. (litre/s) 1 Gadda minor 240 On On On On On On On 2 Bhujela distributary 1550 On On On On On On On 3 Basantpur minor 385 On On On On On On On 4 Majhgaon minor 431 On On On On On On On 5 Mahendranagar distributary 1064 On On On On On On On 6 Bhagatpur minor 260 On On On On On On On 7 Ultakham distributary 1943 On On On On On On On 8 Chunariya minor 124 On On On On On On On 9 Suda minor 1170 On On On On On On On 10 Sisaiya minor 610 On On On On On On On 11 Daiji minor 320 On On On On On On On

(e) Water delivery schedule for dry season (winter and spring)

During dry season, the assured discharge is 4.25 cumecs. This dry season discharge will be delivered in day time (for 10.5 hours a day, from 6:30AM to 5PM) to branch and minor canals of MIS-I. At 5PM head regulators of these canals will be closed till 6:30 AM next morning. The night time flow during that period will flow down to the MIS-II area for distribution to Shivnagar and Belauri main branch canals next morning.

The branch and minor canals of MIS-I shall be divided into two groups. First group will include Gadda minor, Bhujel distributary, Basantpur minor, Majhgaon minor, Mahendranagar distributary and Bhagatpur minor. The second group will comprise Ultakham distributary, Chunariya minor, Suda minor, Sisaiya minor and Daiji minor. These two groups of canals shall receive water as given below:

The two groups will receive water on a rotational basis. Each group of canals will get water nearly equal to design discharge for 3.5 days a week (for 10.5 hours a day, from 6:30AM to 5PM), throughout the dry season. Second group of canals will get water first for 3.5 days, on Sunday, Monday and Tuesday (from 6:30AM to 5PM), and Wednesday (from 6:30AM to 11:45AM). The first group will get supply for next 3.5 days, Wednesday (from 11:45AM to 5PM) and, Thursday, Friday and Saturday (from 6:30AM to 5PM).

Water delivery schedule from main canal to branch and minor canals of MIS-I for dry season is given in Table 21.

Table 21

Gr. Branch and minor canals Discharge Sun Mon Tue Wed Wed Thu Fri Sat No. (litre/s) *Ist **IInd 6:30 AM to 5PM 6:30 AM to 5PM half half 1 Gadda minor 240 Off Off Off Off On On On On Bhujela distributary 1550 Off Off Off Off On On On On Basantpur minor 385 Off Off Off Off On On On On Majhgaon minor 431 Off Off Off Off On On On On Mahendranagar distributary 1064 Off Off Off Off On On On On Bhagatpur minor 260 Off Off Off Off On On On On 2 Ultakham distributary 1943 On On On On Off Off Off Off Chunariya minor 124 On On On On Off Off Off Off Suda minor 1170 On On On On Off Off Off Off Sisaiya minor 610 On On On On Off Off Off Off Daiji minor 320 On On On On Off Off Off Off *Ist half – 6:30AM to 11:45AM **IInd half – 11:45AM to 5PM

4.8.2 From Branch and Minor Canals to Tertiary Canals

(a) Water availability

All the branch and minor canals will get design discharge for all seven days a week (day and night) from the main canal during wet season (monsoon). However, during dry season (winter and spring), these branch and minor canals will have design discharge for 3.5 days a week (from 6:30AM to 5PM) from the main canal.

(b) Water requirement / demand

All the tertiary canals off-taken from branch and minor canals are designed for continuous supply during wet season and rotational supply during dry season. In all branch and minor canals, the tail end tertiary canals do not get their share of water. There are several reasons of this problem – (1) Farmers of head and middle reach draw more water than the design requirement, causing short of supply in tail end, (2) water theft by inserting illegal pipes in the branch and minor canals, (3) leakage from canal and canal structures, and (4) bushes grown in the canal bed.

During wet season, tertiary canals get water every day, but tail end farmers complain that they do not get water. During dry season, tertiary canals get water on rotational basis for 3.5 days a week from parent canal (branch or minor). During this season also tail end farmers complain that they do not get water when needed, and later the head and middle farmers release all the water to tail area to damage the crops, specially wheat crops. To overcome this problem and ensure water delivery to tail end farmers, there could be two alternatives (1) Control the supply of water to head and middle farmers by patrolling along branch and minor canals, and (2) Introduce rotation among tertiary canals. First option needs lots of water guards to control excess water taken by head and middle farmers. Yet it does not

26 ensure water to tail end farmers. The second option is better because tail end farmers can certainly get water on their turn and therefore rotation among tertiary canals is adopted. (d) Water Delivery Schedule

There are eleven branch and minor canals in MIS-I area, which are off-taken from the main canal. For preparing water delivery schedule from branch and minor canals to tertiary canals, Ultakham distributary is taken as sample canal. There are 41 tertiary turnouts in this distributary having almost equal design discharge.

For introducing rotation among tertiary canals, formation of three rotation groups is proposed. In each turn, one group of tertiary canals will be off and other two groups will get water. There could be two methods of group formation – (1) Head tertiary canals in first group, middle tertiary canals in second group and tail end tertiary canals in third group, (2) Number the canal 1, 2, 3, 1, 2, 3, 1, 2, 3 …………. and so on from head to tail of branch and minor canals. Keep tertiary canals having number 1 in first group, number 2 in second group and number 3 in third group.

In first method of group formation, when head tertiary canals are closed, there is risk of overflow of branch and minor canals or wastage of water through escape. Therefore, second method is adopted. Accordingly, tertiary canals of Ultakham distributary are grouped as shown in Table 22. Water delivery schedules for Tertiary Canals of Ultakham distributary for wet and dry seasons are given in Table 23 and 24.

Table 22 : Formation of Groups of Tertiary Canals of Ultakham Distributary

Group 1 Group 2 Group 3 UL 1/1 UL 1/2 UL 2/2 UL 2/1 UL3/1 UL3/2 UL3/3 UL4/2 UL4/1 UL6/1 UL6/2 UL6/3 UL6/4 UL7/1 UL7/2 UL8/1 UL9/R1/1 UL9/R1/2 UL10/3 UL10/1 UL10/2 UL10/3A UL11/1 UL11/2

UL5/2 UL5/L1/1 UL5/L1/2 UL5/L1/3 UL5/L1/4 UL5/L1/6 UL5/L1/5 UL5/L1/8 UL5/L1/10 UL5/L1/7 UL5/L1/9 UL5/L1/11 UL5/L1/16A UL5/L1/13 UL5/L1/14 UL5/L1/15 UL5/L1/16

Table 23: Water Delivery Schedule of Tertiary Canals of Ultakham (for Wet Season)

Group Branch and minor canals Sun Mon Tue Wed Thu Fri Sat No. 6:30 AM to 5PM Group 1 UL 1/1 Off Off On On On On On UL 2/1 Off Off On On On On On UL3/3 Off Off On On On On On UL6/1 Off Off On On On On On UL6/4 Off Off On On On On On

UL8/1 Off Off On On On On On UL10/3 Off Off On On On On On UL10/3A Off Off On On On On On UL5/2 Off Off On On On On On UL5/L1/3 Off Off On On On On On UL5/L1/5 Off Off On On On On On UL5/L1/7 Off Off On On On On On UL5/L1/16A Off Off On On On On On UL5/L1/15 Off Off On On On On On Group 2 UL 1/2 On On Off Off On On On UL3/1 On On Off Off On On On UL4/2 On On Off Off On On On UL6/2 On On Off Off On On On UL7/1 On On Off Off On On On UL9/R1/1 On On Off Off On On On UL10/1 On On Off Off On On On UL11/1 On On Off Off On On On UL5/L1/1 On On Off Off On On On UL5/L1/4 On On Off Off On On On UL5/L1/8 On On Off Off On On On UL5/L1/9 On On Off Off On On On UL5/L1/13 On On Off Off On On On UL5/L1/16 On On Off Off On On On Group 3 UL 2/2 On On On On Off Off On UL3/2 On On On On Off Off On UL4/1 On On On On Off Off On UL6/3 On On On On Off Off On UL7/2 On On On On Off Off On UL9/R1/2 On On On On Off Off On UL10/2 On On On On Off Off On UL11/2 On On On On Off Off On UL5/L1/2 On On On On Off Off On UL5/L1/6 On On On On Off Off On UL5/L1/10 On On On On Off Off On UL5/L1/11 On On On On Off Off On UL5/L1/14 On On On On Off Off On

Table 24 : Water Delivery Schedule of Tertiary Canals of Ultakham (for Dry Season)

Group Branch and minor canals Sun Mon Tue Wed Wed Thu Fri Sat No. *Ist **IInd 6:30 AM to 5PM 6:30 AM to 5PM half half Group 1 UL 1/1 Off On On On Off Off Off Off UL 2/1 Off On On On Off Off Off Off UL3/3 Off On On On Off Off Off Off UL6/1 Off On On On Off Off Off Off UL6/4 Off On On On Off Off Off Off UL8/1 Off On On On Off Off Off Off UL10/3 Off On On On Off Off Off Off UL10/3A Off On On On Off Off Off Off

UL5/2 Off On On On Off Off Off Off UL5/L1/3 Off On On On Off Off Off Off UL5/L1/5 Off On On On Off Off Off Off UL5/L1/7 Off On On On Off Off Off Off UL5/L1/16A Off On On On Off Off Off Off UL5/L1/15 Off On On On Off Off Off Off Group 2 UL 1/2 On Off On On Off Off Off Off UL3/1 On Off On On Off Off Off Off UL4/2 On Off On On Off Off Off Off UL6/2 On Off On On Off Off Off Off UL7/1 On Off On On Off Off Off Off UL9/R1/1 On Off On On Off Off Off Off UL10/1 On Off On On Off Off Off Off UL11/1 On Off On On Off Off Off Off UL5/L1/1 On Off On On Off Off Off Off UL5/L1/4 On Off On On Off Off Off Off UL5/L1/8 On Off On On Off Off Off Off UL5/L1/9 On Off On On Off Off Off Off UL5/L1/13 On Off On On Off Off Off Off UL5/L1/16 On Off On On Off Off Off Off Group 3 UL 2/2 On On Off On Off Off Off Off UL3/2 On On Off On Off Off Off Off UL4/1 On On Off On Off Off Off Off UL6/3 On On Off On Off Off Off Off UL7/2 On On Off On Off Off Off Off UL9/R1/2 On On Off On Off Off Off Off UL10/2 On On Off On Off Off Off Off UL11/2 On On Off On Off Off Off Off UL5/L1/2 On On Off On Off Off Off Off UL5/L1/6 On On Off On Off Off Off Off UL5/L1/10 On On Off On Off Off Off Off UL5/L1/11 On On Off On Off Off Off Off UL5/L1/14 On On Off On Off Off Off Off *Ist half – 6:30AM to 11:45AM **IInd half – 11:45AM to 5PM

3.9 WUA Policy of Water Distribution

WUA Block Committee is mainly responsible for water distribution to the tertiary canals. This committee should form a canal operation sub-committee with one of its executive member as coordinator. The water from branch and minor canals should be distributed to tertiary canals according to the water delivery schedules of the tertiary. The block committee should make an arrangement of patrolling along the branch and minor canals so that tertiary canals are not opened on off days. The block committee should encourage the farmers to take their share of water on their turn only.

The tertiary committee should prepare water distribution plan from field outlets to the farmers’ fields, mentioning name of farmers, their land holding, number of hours and time period allocated to them based on their landholding and rotational order agreed with farmers.

Chapter-4 Organization for Canal Operation Plan Management

4.1 Existing Organization

Mahakali Irrigation System is operational under joint management of Department of Irrigation and Mahakali Water Users’ Association, Central Committee. The central committee helps MPMIMD in making decisions about operation of main canal. Irrigation Management of MIS-I has been transferred to Mahakali Irrigation Water Users’ Association, First Stage Regional Committee. The WUA of MIS-I has taken the responsibility of operation and maintenance of branch, minor and tertiary canals and equitable distribution of water to farmers. However, the responsibility of operation and maintenance of the main canal lies with Mahakali, Pathraiya, Mohana Irrigation Management Division (MPMIMD).

4.1.1 Organization of WUA of MIS Stage-I

WUA of MIS Stage-I has Regional Committee at the top, 5-Block Committees in the middle and 201-Tertiary Committees at the bottom. Regional Committee has coordination and monitoring roles in canal operation management. Block committees have to play crucial role for efficient and equitable distribution of water. And, the Tertiary Committees are expected to distribute the available water to the farmers equitably. Role of the tertiary committees are very important. That is why these committees should be very active and action oriented. Irrigation service to the farmers can be provided in true sense through these committees only.

Organization of WUA of MIS-I

First Stage Regional Committee

Block Committees (5 No.)

Tertiary Committees (201 No.)

Figure 4

4.1.2 Organization of Irrigation Management Division

Mahakali, Patharaiya, Mohana Irrigation Management Division (MPMIMD) has one Senior Divisional Engineer as Division Head, 3 Engineers and 2 Sub-Engineers supported by gate operators and water guards for canal operation management of the main canal, Shivanagar Main Branch Canal and Belauri (M3) Main Branch Canal. Overall responsibility of operation management of main canal lies with Senior Divisional Engineer. Engineer (1) has the responsibility of operation management of main canal (from Border weir upto Daiji Cross- Regulator), Engineer (2) has the responsibility of main canal (from Daiji Cross-Regulator to end of main canal at Kalikich) and Shivanagar Main Branch, and Enginner (3) is responsible

30 for operation management of Belauri (M3) Main Branch. Sub-Engineer (1) is assigned to assist Engineer (1) and Engineer (2) in canal operation management and Sub-Engineer (2) is assigned to assist Engineer (3). 4.2 Procedures of Canal Operation and Communication

4.2.1 Procedures of Canal Operation

(a) Preparation for canal operation

1. Inform water user farmers and general public about the date of commencement of canal operation for a particular crop season – monsoon, winter and spring, through electronic and print media, at least 15 days before the opening date of main canal. 2. Prepare Water delivery schedule 1- from main canal to branch/minor canals and Water delivery schedule 2- from branch/minor canals to tertiary canals based on previous records and finalize the same in consultation with WUA. 3. Prepare communication system and mechanism for canal operation. 4. Set up canal operation control and information desk at IMD office. 5. Water level gauge marking on water measuring structures and full supply level marking on the other structures should be painted. 6. Calibrate water measuring structures along main canal and bulk delivery (from main canal) points. 7. Carry out lubrication and greasing of gates of head regulators, cross regulators, turnouts and escape regulators before the opening date. 8. Pack up all the construction and repair works going on in canals well before the opening date. 9. Keep all the staff, maintenance work force and equipments in ready position. 10. Assign duties and work area of staff - engineers, sub-engineers, gate operators / water guards, and WUA members. 11. Orient the staff and WUA members about the plan, strategies, activities and, rules and regulations. 12. Inform district administration about canal opening and request for necessary cooperation and protection from notorious people during canal operation.

(b) Canal operation techniques

 In the beginning of crop season, when water is first released into the main canal, a low supply should be run for a few hours for canal priming purposes and then the discharge be gradually raised according to requirements. The gates of head regulators of branch and minor canals should be in closed position during this process.  The gates at the cross regulators should be lowered only after the main canal has been run for some time. The lowering of gates should be to the extent necessary to create the full supply level. The downstream of the main canal should not be kept dry with full supply level upstream of the regulator unless conditions require the same and the structure is design for it. However, in no case water should flow over top of any gates.  Once full supply level is reached in the main canal, water can be distributed to branch and minor canals. During the water distribution periods, branch and minor canals should run at full supply level so that the tertiary canal turnouts can draw their stipulated share of water.

 In case for some reason it is not possible to run the canal at its full supply level, the water level in the canal should be controlled by operating the gates of Cross Regulators so that sufficient head of water is available at the Head Regulators of tertiary canal turnouts.  Both the gates of Cross Regulator should be opened equally to ensure uniform flow and hence the safety of the structure.  When there is an unscheduled fall in demand, for example, due to rainfall, the tertiary canal turnouts should be closed to avoid crop damage from over-watering and water stored in the branch and minor canal should be released through the escapes to the drains after ensuring adequate safety of downstream area. At the same time, the gates of head regulator of branch and minor canal should be gradually closed.  Due to decrease in demand at head regulator of branch and minor canals, the water stored in the main canal should be released through escape regulators. If it is still required, supply into main canal be reduced or stopped.  At the end of crop season, the regulators of canals should be closed gradually in order to avoid slumping of the inside slope of the canals usually caused by sudden draw down of water in the canal.

 Main, branch and minor canals should always be maintained in reasonably good condition.  All canals shall be operated as per bulk water delivery and the water delivery schedules agreed with WUA before commencement of each irrigation season.  If the available water supply is not sufficient to meet the requirement of canals, the flow through the canals should be reduced proportionately in consultation with WUA.  Flow in the main canal at border weir and bulk water delivery from main canal to branch and minor canals should be measured daily as specified and properly recorded in the given water measurement register.  Information of discharge measured at border weir and bulk water delivery to branch and minor canals should be given/sent to canal operation control and information desk at IMD office regularly as per instruction of concerned engineer.  Water delivered from main canal into branch and minor canals should be distributed by WUA to tertiary canals as per water delivery schedule equitably and efficiently.  Patrolling of main canal should be done regularly by water guards, sub-engineers and engineers. Similarly, patrolling of branch and minor canals should be done by concerned WUA member. Any important events and activities observed / noticed during patrolling should be recorded and communicated to the concerned authority.  Information of opening and closure of canals, and releasing water through the escape should be communicated to WUA and farmers well before these events.  Information about demand for water should be communicated to the authorized person through the proper communication channel in normal condition, and directly to him in case of emergency.  The canals should be inspected by authorized person each time in case of occurrence of excessive rainfall in the command area.  All the staff, WUA members and water users should follow water delivery schedules and water regulations.

4.3 Proposed Personnel and Skill Required

For canal operation of main canal, Engineers (engineering graduate), Sub-Engineers (diploma engineers) and gate operators/water guards (who can operated gates, read the gauge and find the discharge from table) are required. Similarly, for operation of branch and minor canals, WUA members and water guards are needed.

4.4 Proposed Organization and Staff Scheduling

4.4.1 Main Canal operation:

MPMIMD is responsible for operation and maintenance of main canal. MPMIMD has one Senior Divisional Engineer, 3 Engineers, 2 Sub-Engineers and gate operators /water guards. Numbers of Engineers and Sub-Engineers are fixed. Ten gate operators /water guards are working in the main canal (MIS-I portion). Senior Divisional Engineer has overall responsibility of operation and maintenance. One Engineer is assigned the responsibility of operation of main canal (MIS-I portion). He is supported by 1 Sub-Engineer and 10 gate operators /water guards. The work area of the gate operators / water guards is as follows:

Table 25 Station Work area Water guards

Gadda CR Border weir, Gadda HR, Gadda CR, Gadda 2 No Escape, Bhujela distributary HR, and Basantpur minor HR Mahendranagar CR Majhgaon minor HR, Mahendranagar 2 No distributary HR and CR Bhasi CR Bhagatpur minor HR, Ultakham HR and CR, 2 No Chunariya minor CR Suda CR Suda Minor HR, Suda CR, Ghorsuwa CR and 2 No Escape, Bhindi Chauaraha CR and Sisaiya HR Daiji CR Daiji minor HR and CR, Balama Escape 2 No

4.4.1 Branch and minor canals operation:

WUA Block Committees are responsible for operation of branch and minor canals and distribution of water to the tertiary canals. There are 11 officials and members in the block committees. In addition, MPMIMD has provided 2-3 water guards to block committees. Block committees depend on these water guards for canal operation and water distribution.

Except Block E, each block has 2 to 3 branch and minor canals. Performance of water distribution from these canals to tertiary canals can be improved if each block committee forms a canal operation sub-committee for each branch and minor separately, under the leadership of one of its executive members. The executive member is allowed to choose members of the sub-committee from tertiary committee chair persons.

Chapter-5 Monitoring and Evaluation of Canal Operation

Monitoring and evaluation (M&E) of canal operation can be defined as a system of data gathering, analysis and feedback of canal operation activities and expected outputs. It aims to improve performance of canal operation.

For systematic data gathering, an M&E plan should be prepared, which should contain the list of activities and expected outputs, monitoring indicators, source of data, method of data gathering, frequency of data collection and the responsible person/s. The M&E plan for canal operation of MIS-I is given below.

Table 26 M&E plan of Canal Operation of MIS-I

Activities Monitoring Data Source of Method of Frequency Responsible and indicators data data of data person/s expected gathering collection outputs 1. Improved % of delivery Discharge Discharge Review of Weekly M&E sub- bulk water points measured measurement Discharge committee for service receiving at head records of measurement main canal delivery by proportionate regulators delivery points records operation DoI to WUA share of water of branch as per agreed and minor plan canals 2. Efficient % of tertiary No. of Flow Records Review of Fortnightly M&E sub- and equitable canals getting days of kept by flow records committee for distribution proportionate getting Tertiary branch and of water by share of water water by Committee minor canal WUA tertiary operation canal

M&E sub-committee for main canal operation will consist of :  MPMIMD Chief – Coordinator  Chairman of WUA Central Committee – Member  Chairman of WUA Regional Committee, MIS-I – Member

Similarly, M&E sub-committee for branch and minor canal operation will consist of :  Chairman of WUA Regional Committee, MIS-I – Coordinator  Chairman of WUA Block Committee of respected block – Member  Coordinator of canal operation sub-committee of respected brach and minor canal - Member

M&E sub-committees will prepare brief report on each visit and a comprehensive M&E report at the end of each crop season.

References

Aryal and Main System Management Mahakali Irrigation Project Kanchanpur, paper published in Sharma (1992) Proceedings of National Workshop of Department of Irrigation, 1992, by M.N. Aryal and S.R. Sharma FAO (1982) Organization, operation and maintenance of irrigation schemes, FAO irrigation and drainage paper 40, by FAO - Food and Agriculture Organization of The United Nations Rome, FAO Land and Water Development Division 1982 (Reprinted 1986). FAO (1986) Irrigation Water Management Training Manual No. 3, Irrigation Water Needs, published by, Food and Agriculture Organization of the United Nations, Rome, Italy, February 1986. FAO (1998) FAO Irrigation and Drainage Paper 56 : Crop Evapotranspiration - Guidelines for computing crop water requirements, produced by Natural Resources Management and Environment Department, Food and Agriculture Organization of the United Nations, Rome, Italy, (1998) FAO (1992) Irrigation Water Management, Training Manual No. 3, Canals, published by, Food and Agriculture Organization of the United Nations, Rome, Italy, 1992. GOG (2009) Operation and Maintenance Guidelines for Canals, by Government of Gujarat, Narmada Water Resources Water Supply & Kalpsar Department, April 2009 GOR (2010) Guidelines to Prepare Manual of Operation & Maintenance of Irrigation Structures, prepared by Government of Rajsthan, Department of Water Resources, (October 2010) Hatcho, N. Demand management by irrigation delivery scheduling , in Water and the Environment: (1998) Innovation issues in irrigation and drainage, edited by John W. Going, Luis Santos Pereira, May 1998. Mahakali (1996) Treaty between His Majesty’s Government of Nepal and The Government of India Concerning The Integrated Development of the Mahakali Barrage including Sarada Barrage, Tanakpur Barrage and Pancheshwar Project, signed on 12 Feb. 1996. PDSP (1990) Design Manuals for Irrigation Projects in Nepal: M.3 Hydrology and Agro-meterology Manual, prepared by Planning and Design Strengthening Project, Department of Irrigation (Nepal), February 1990 WB (1980) Staff Appraisal Report- Mahakali Irrigation Project (Stage I), World Bank Document, Report No. 2931-NEP, January 1980. TA (2016) Unpublished reports and guidelines provided by Senior Water Management Engineer of IWRMP –B, TA, 2016