What is irrigation system|surface irrigation| |Case study of Bagmati irrigation project in Nepal

Surface irrigation in Bagmati:- Agriculture, the mainstay of Nepal economy employing nearly 90 % of the labor force is basically of substance nature. Bagmati Irrigation Project (BIP) is one of the national top priority irrigation projects. It accounts 2.1 % in first phase and 6.9 % in second phase out of total national irrigable area. The annual growth rate of Nepal is 2.4 % but the agricultural growth rate is only 1.2 %. Water management can help improving production and make the country self sufficient in food production.

Rapid Appraisal process (RAP) is a quick methodology to evaluate an irrigation project to get idea of what type of modernization is needed. Any irrigation project needed continuous performance evaluation for the effective utilization of the resources and it is applicable for BIP. The BIP project is performing substantially well in terms of productivity and water use despite of the low network of the canal system. The internal indicators having less than 50% weightage provide the basis for a rational programme of improvement, which will enhance the operation, management and output of the project. RAP is essential for continuous project evaluation of BIP. Keeping in this view the study entitled “Rapid Appraisal of Bagmati Irrigation Project in Nepal.”

Lifting Gates used in Irrigation — FIg1. headworks in river

Lifting gates used in Barrage of Irrigation Project — FIg1. headworks in river

BAGMATI IRRIGATION PROJECT INTRODUCTION

Agricultural is vital for rural employment.Nepal has planned to increase its agricultural production at a rapid rate through irrigation development. This also needed continuous performance evaluation for the effective utilization of the resources. BIP also required frequent performance evaluation, which is essential. It would be achieved quickly through RAP. A RAP quickly evaluates an irrigation project to get idea of what type of modernization is needed. The RAP includes external and internal indicators

Bagmati Irrigation Project (BIP) is Agency Managed Irrigation System (AMIS) with the command of 37000 ha in first phase out of which 14000 ha in Sarlahi district of Janakpur Zone and 23000 ha in Rauthat district of Narayani Zone. Bagmati River is perennial. The project started as Sunkoshi Terai Project during 1978/79 with financial support receives from UNDP, DELF Relief Fund (Japan) and presently Saudi Development Fund. Canal with structures to irrigate about 30000.0 ha (command area development) of arable land is going to complete in near future. It is proposed to irrigate 122000 ha in Sarlahi, Bara, Rauthat, Mahottari and Dhanusha district in the end of second phase. Total irrigable area of country is 1766000 ha out of which BIP accounts 2.1 % in first phase and 6.9 % in second phase of total national irrigable area. Water management can help improving production and make the country self sufficient in food production. Rapid Appraisal process (RAP) is a quick methodology to evaluate an irrigation project to get idea of what type of modernization is needed. Any irrigation project needed continuous performance evaluation for the effective utilization of the resources and it is applicable for BIP.

32 WUA formed up to till now in those areas where command area development works have been completed. They are doing repair, maintenance and water management work in tertiary canal and are in close contact with project for other canal system maintenance and water management work.

Water Management in the face of the growing water scarcity and increasing population in order to continue on the path of the socio- economic development needs effective institutional arrangement and right allocation of water to user’s. Performance of irrigated agriculture is improved by reliable supply of water.

The irrigation systems to be modernized support rice cultivation as the main crop during the dry season. Modernizing the irrigation and drainage systems will result in water savings, improved water productivity and diversify the crop. There is wide range of levels of irrigation service and the nature of the service may very from highly flexible service to inflexible service up to farm level. It is important to emphasize that an irrigation project is a network of many hydraulic delivery layers and each layer provides service to next lower level. The level of the service may be different at each layer. It is therefore important to identify what existing level of service is and what is expectation. A good water delivery system is expected to be flexible characterized by frequency; flow rate; duration; equity reliability and timeliness. Equity is the prime goal of any Farmers Managed Irrigation System in Nepal.

Description of the Bagmati Irrigation Project

Bagmati Irrigation Project is one of the national priority irrigation projects in Nepal. It is a large-scale project. It lies in the Sarlahi district of Janakpur zone with a catchments area of 2720 sq. km. It irrigates 14000 ha in Sarlahi district of Janakpur zone and 23000 ha in Rauthat district of Narayani zone thus have total command area of 37000 ha in first phase. It is proposed to irrigate 122000 ha in Sarlahi, Bara, Rauthat, Mahottari and Dhanusha district in the end of second phase. The main aim of this project is to improve living standard of farmers, check trans migration and provide work opportunity in the command.

Bagmati River is a perennial river, originating from Himalayas. Barrage is located in the upstream of Bagmati River from East-West highway having 403.5 m length. It has 17.1 km eastern main canal with 64.4 cumecs discharge capacity. This has three branch canals viz Manpur,Gadhaiya and Laxmipur irrigating 14000 ha command area. It has 28.2 km Western Main Canal with three branch canals viz Bhalohiya, Bahuyari and Baghi irrigating 23000 ha command are
Description of the Bagmati Irrigation Project .

Location of Bagmati irrigation project

The project area lies between longitudes 85⁰17′ to 85⁰36′ East and latitude 26⁰46′ to 27⁰6′ North, and Comprises of land in the Sarlahi district of Janakpur Zone and Rauthat district of Narayani Zone of the Central Development Region. The command area of the project lies in the south of East-West high way and north is the Churia hills. It is a flat plain with ground elevations varying typically, between 60m above mean sea level on the southern border with India to 130m at the boundary of Siwalik, and is called the Terai. The major rivers within the project area are Lal Bakeya, Lamaha, Chandi, Bagmati, Lakhandei and Jhim. The source of water for irrigation supply is Bagmati River.

Climate and Hydrology of Bagmati Irrigation Project

Climatic conditions in the project area are dominated by monsoon. Averages annual rainfall is 1440 mm. There is considerable year-to-year variation in precipitation. The wet season extends over the period of four months from June to September. Mean annual temperature is 25⁰C ranging from 16⁰C in January to 30⁰C in May and June. Relative humidity ranges from 54% in April to 83% in August. Agro-climatically these conditions are favorable for exploitation of agricultural potential. Discharge record of the rivers in the project area is available only at Karmaiya station in the Bagmati River. The average annual discharge for the period of 1965-75 at Karmaiya, which has a catchments area of 2700 km2, is estimated 177m3/sec with a minimum of 129m³/sec and maximum of 216m³/sec. Over 80% of run off occurs in the four months from June to September. The mean monthly discharge fluctuates from 586m³/sec in July to14.8m³/sec in April. In addition to river water, shallow and deep ground water is available in the project area.

Agriculture

The existing cropping patterns differ in different locations and of the command area depending upon availability of irrigation water, land type and the nature of the farming practices. The cropping patterns in the project of Sarlahi and Rauthat districts as a whole are furnished below. The existing cropping patterns for different situations such as irrigated and partially irrigated conditions are given in the Table 2 and 3.

Table 2: Major cropping patterns under irrigated condition are:

1	Paddy	Wheat	Fallow
2	Paddy	Oilseed	Spring Paddy
3	Paddy	Pulses	Fallow
4	Paddy	Fallow	Paddy
5	Paddy	Oilseed	Maize
6	Paddy	Fallow	Maize

Table 3: Major cropping patterns under partially irrigated condition are: 1

1	Paddy	Wheat	Fallow
2	Paddy	Pulses	Fallow
3	Paddy	Oilseed	Spring Paddy
4	Paddy	Maize
5	Paddy

Source: Feasibility Study on Bagmati Command Area Development Project, Nippon Koei Co., Ltd. in association with Sir William Halcrow and Partners Ltd. and Multi Disciplinary Consultants (P) Ltd., 1992.

Paddy – Wheat is the dominant cropping pattern in the both irrigated and partially irrigated conditions, while paddy- oilseed/pulses is the major dominant pattern in the rainfed conditions. Sugarcane is largely grown under rainfed condition. The major oilseed are mustard and linseed, while the major pulses constitute lentil, lathyrus and chickpeas. Cropping index shows about 170 %. Paddy yield is up to 4.0 MT/ha in the project area (Progress Report, BIP, 2004).

Water User’s Association

Agriculture, the mainstay of Nepal economy employing nearly 90 % of the labor force is basically of substance nature. Bagmati Irrigation Project (BIP) is one of the national top priority irrigation projects. It accounts 2.1 % in first phase and 6.9 % in second phase out of total national irrigable area. The annual growth rate of Nepal is 2.4 % but the agricultural growth rate is only 1.2 %. Water management can help improving production and make the country self sufficient in food production.

BAGMATI IRRIGATION PROJECT INTRODUCTION

Description of the Bagmati Irrigation Project

Location of Bagmati irrigation project

Water User’s Association

Water User’s Association (WUA) plays a vital role in irrigation development and management. User’s association registration started from 1998 in the area where command area work has been completed in the tertiary level canal. Project is planning to register up to main canal level and hand over the system those who are capable to regulate, operate and maintained the system. Registration is under the process.

Bagmati Irrigation Project (BIP) is under construction phase. Command area development work has been completed on the 30000 ha out of 37000 ha command area and 7000ha has been proposed for construction. 28 water users association registered during 1997-98. There is only one association organizer recruited in the office. Which is not sufficient to look after all. Project officials carry out major construction work. Maintenance work is carried out through WUA. During 2004 devastating flood damaged the canal network in July, at the same time drought occurs long time during the rice growing period. They are forced to regulate water through canal for their betterment. They started to register more and more water users association according to irrigation policy 2003. They were given training and innovative program through BIP. They were familiar with rule, regulation and policy. Most important fact is that they feel scare water will be available only especially in the tail end of canal through rotation system in the presence of effective WUA. Small economic incentive, conscience with rule and regulation to cope up with drought situation, they started to registered the WUA with active participation of BIP. During July 2005, 4 WUA registered in BIP and around 20 number of WUA are in process of registration. Total number of registered WUA becomes 32. Their active participation improved the agricultural performance of the BIP by improving the defunct network of canal system.

Salient Feature of the System

(a) Design flood discharge 8000.0 Cumecs

(b) Design discharge of eastern main canal 15.0 Cumecs

(A) Barrage (Completed)
Length 403.5 m	Gate 36 no.
(B) Head Regulator (Completed)
Eastern Head Regulator	Western Head Regulator
Width	Gate No.	Discharge	Width	Gate No.	Discharge
37.0 m	7.0	64.4 Cumec	26.0 m	5.0	48.3 Cumecs

C) Canal System

Canal System (Sarlahi)	Canal System (Rauthat)
S.N.	Name of Canal	Length (Km.)	CCA (ha.)	S.N.	Name of Canal	Length (Km.)	CCA (ha.)
1	EMC (Completed)	17.1	14000	1	WMC (Completed)	28.2	23000
2	Branch Canal (Completed)	48.45	14000	2	Branch Canal (Completed)	62.2	23000
(a) Manpur	12.45	5100	(a) Bhalohiya	32.20	15000
(b) Gadhiya	19.00	4000	(b) Bahuari	12.00	2000
(c) Laxmipur	17.00	4900	(c) Baghi	18.00	6000
3	Distributory Canal (Completed)	66.89	12656	3	Distributory Canal (Completed)	45.95	8647
(a) Sakraul	9.20	2200	(a) Bhusha	8.25	1574
(b) Bishnupur	10.00	1520	(b) Samanpur	10.60	2284
(c) Barahathawa	8.00	1156	(c) Zingariya	10.00	1493
(d) Sundarpur	7.50	2048	(d) Birta	2.20	1158
(e) Rajghat	11.30	1230	(e) Madhopur	7.00	990
(f) Hazariya	2.95	927	(f) Laukaha	7.9	1148
(g) Shripur	2.95	902
(h) Dhangadha	3.35	540
(i) Parariya	7.00	2133

Source: Bagmati Irrigation Project, Progress Report, 2004

Water Regulation and Distribution System

There is no fix rule for water distribution. It is ad hock basis. Beside command area developed section, farmers use direct outlet from main and branch canal. Farmers of the concerning outlet discuss to each other and upon agreement, they made a demand to project site office or if the water is available, they draw own self. Upon there demand, site Engineer, inform to project manager to regulate water in the concerning area. Upon project consent, gate operator regulate the system. It is a trial and error basis. Nobody knows actual supply and demand. Head section uses more water then the tail section. Sometimes stronger people use more water.

Pier in Headworks in surface irrigation system

MODERNIZATION CONCEPTS AND STRATEGIES 2

(2 The following section is drawn from Wolter and Burt, 1996 and Facon, 1997.36)

Appropriate modernization is a process, which incorporates new design procedures and new equipment with a vision of future operations. Modern design is the result of a thought process. Configuration and the physical components are selected in the light of a well-defined and appropriate operational plan. Advanced concepts of hydraulic engineering, irrigation engineering, agronomy and social science should be used to arrive at the most simple and workable solution. A modern irrigation design is not primarily defined by specific hardware components and physical configurations, but will have all or some of the following characteristics:

The-overriding principle of modern irrigation(surface irrigation) is that irrigation is a service to farmers, which should be as convenient and efficient as possible. Farmers ultimately have to generate the benefits, which keep the system functioning.
Modern irrigation schemes can be imagined to consist of several sub-systems or levels with clearly defined interfaces, where water is measured and controlled.
Each level is financially autonomous and hydraulically as independent as possible. Transactions at each level are transparent for the next lower or upper level.
Each level is technically able to provide reliable and timely water delivery to the next lower level. At each level there are the proper types, numbers and configurations of gates, turnouts, measurement devices, communication systems and otheSalient Feature of the Systemr means to control flow rates and/or water levels as desired.
Each level is responsive to the needs of its clients. Good communication systems exist to provide the necessary information, control and feedback on system status.>
Each level of delivery has confidence, based on enforceable rights, in the reliability, timeliness, and equity of water, which will be supplied from the next higher level. Effective mechanisms for conflict resolution are in place.
The hydraulic design of the water delivery system is created with a well-defined operational plan in mind. The operational plan is established with a clear understanding of the needs of the end users.
The hydraulic design is robust, in the sense that it will function well in spite of changing channel dimensions, siltation, and communications breakdowns. Automatic devices are used where appropriate to stabilize water levels in unsteady flow conditions.
Motivated and trained operators are present at all levels of the system. They are not necessarily the farmers themselves but preferably hired professionals. Instructions for individual operators are well understood and are easy to implement.
Maintenance is the obligation of each level. Maintenance plans are defined during design and are adequately funded and implemented.

The-overriding principle of modern surface irrigation is that irrigation is a service to farmers, which should be as convenient and efficient as possible. Farmers ultimately have to generate the benefits, which keep the system functioning. Modern irrigation schemes can be imagined to consist of several sub-systems or levels with clearly defined interfaces, where water is measured and controlled. Each level is financially autonomous and hydraulically as independent as possible. Transactions at each level are transparent for the next lower or upper level. Each level is technically able to provide reliable and timely water delivery to the next lower level. At each level there are the proper types, numbers and configurations of gates, turnouts, measurement devices, communication systems and otheSalient Feature of the Systemr means to control flow rates and/or water levels as desired. Each level is responsive to the needs of its clients. Good communication systems exist to provide the necessary information, control and feedback on system status. Each level of delivery has confidence, based on enforceable rights, in the reliability, timeliness, and equity of water, which will be supplied from the next higher level. Effective mechanisms for conflict resolution are in place. The hydraulic design of the water delivery system is created with a well-defined operational plan in mind. The operational plan is established with a clear understanding of the needs of the end users. The hydraulic design is robust, in the sense that it will function well in spite of changing channel dimensions, siltation, and communications breakdowns. Automatic devices are used where appropriate to stabilize water levels in unsteady flow conditions. Motivated and trained operators are present at all levels of the system. They are not necessarily the farmers themselves but preferably hired professionals. Instructions for individual operators are well understood and are easy to implement. Maintenance is the obligation of each level. Maintenance plans are defined during design and are adequately funded and implemented.

Result and Discussion about Bagmati irrigation project

Nepal has invested large amount of capital for surface irrigation development. BIP is one of the top national priority irrigation projects. Rapid Appraisal process (RAP) using the field questionnaire to compute internal performance indicator was performed on 1st August 2005. Result shows in the tabular form. Most of the internal indicators are below 2 out of 0-4 rating scale. Farmers and canal systems were visited in the site. Result shows the need of modernization of the BIP for effective utilization of resources.