Detailed Feasibility Study and Agri-Economic Analysis of Bhabar Lift Irrigation Project, Dadheldhura

The study assessed the technical, environmental, social, and economic feasibility of the Bhabar Lift Irrigation Project, confirming its viability.

Abstract  

Bhabar Lift Irrigation Project has been proposed based on the genuine demand of farmers who have agreed to comply with the Irrigation Policy/procedures throughout the sub-project development process and operation and maintenance after completion. The project has a gross command area of 30 Ha, with a net command area of 25 Ha. Water is pumped from the intake to the tank at the head of 80 m through a proposed 80 mm dia GI pipe to deliver water from the well to the reservoir. The project aims to benefit 122 households with a population of 800 people, by providing them with a consistent water supply. Currently, agriculture practices in the area are completely dependent on rainwater and the present cropping intensity is 130%, with maize and pulses being the major crops. However, after the completion of the project, the future cropping intensity is expected to reach 232%. The proposed development plan includes an intake, pipeline works, reservoir tank, and electrical pumping system installation with a total cost of Rs. 15,136,000.00. Farmers have been extensively consulted and involved in the development of the project plan, with their active participation being a vital aspect. Comprehensive economic analysis shows that the project is technically feasible, environmentally friendly, socially acceptable, and economically viable, with an EIRR of 19.91% and a B/C ratio of 1.91 and 1.66, respectively. Overall, the feasibility study concludes that the project should be implemented, and the farmers are enthusiastic about its potential success. Further training in areas such as O&M, water management, and leadership development will be essential to ensure that farmers can take full advantage of the project's benefits.  

Keywords: Cropping Intensity, EIRR, Reservoir, Pump  

Authors: 

✏️ Roshan Pandey1, Er. Rupesh Acharya1, Er. Ramesh Regmi2

1Chief Executive Officer, Green Eye Engineering Solutions Pvt. Ltd., Sunsari, Nepal 

2Engineer, Agriculture Knowledge Center, Palpa, Nepal 

Introduction  

Lift irrigation is an important source of water for agriculture in Nepal, especially in areas with limited water availability. However, the feasibility of implementing lift irrigation systems and the economic benefits they can provide for farmers are often unclear. Therefore, conducting a feasibility study and agri-economic analysis of lift irrigation systems is necessary to assess their viability and potential impact on agriculture in Nepal. This analysis should consider factors such as the availability and quality of water sources, the terrain and topography of the area, the cost and maintenance of lift irrigation systems, and the potential impact on crop yields and farmer incomes. The results of such a study can provide valuable information for policymakers and investors to make informed decisions about the implementation of lift irrigation systems and their potential impact on rural communities in Nepal. Reviewing the literature, “ The study Assessing the Operation Management: A Case of Narayani Lift Irrigation System, Nepal” used field visits, surveys, and interviews to collect data, which was analyzed using various methods. The system's past performance showed limited irrigation coverage, occasional supplements, and frequent disputes during water distribution. The role of NLIWUA was effective in managing these disputes. The system has brought about changes in the socioeconomic and agricultural status of the users, including an increase in economic status and a shift from rice plantations to cash crops. The system needs proper rehabilitation as the allocated budget is only sufficient for temporary maintenance, and sediment management is a significant problem. The study “Enhancing Water Productivity in Agriculture at Fokshingkot Lift Irrigation System” briefs that a high-head lifting/pumping system was constructed that successfully delivers 1.94 liters per sec of water for drinking and irrigation. This has benefited 102 households, saved time for women and children, and increased household income through farming.   

The Bhabar Lift Irrigation Project is located in the Alital-5 region of Sudur Paschim province in Nepal, with a proposed lifting point at a latitude of 29° 7'54.29"N & longitude of 80°29'46.68"E.  

Access to the project area is provided by nearby roads such as the Bhimdutta Panta Highway & Mahakali Highway, and the specific road for the site is Jogbuda-Alital or Budor to Alital. The water in Rangun Khola is sufficient for the pumping requirement.  

The study of Bhabar Lift Irrigation includes feasibility analysis, the construction of necessary irrigation infrastructure to ensure reliable water supply, providing year-round irrigation to the area, and increasing cropping intensity and productivity. Additionally, the project aims to strengthen water user associations and institutions, promote advanced farming technologies, and increase farm income.  

Methodology  

To achieve the objectives, the project team conducted field visits, topographical surveys, and focus group discussions to identify the location of the lifting point, source, and reservoir. GPS surveys were conducted to determine the altitude and location of the source and command area. The results of the digital data were then imported into CAD and GIS software for further analysis.  

The float method was used to measure discharge, and the cross-sectional areas at the start and endpoints of the reach were measured and plotted in the graph using a suitable scale. Discharge was computed by multiplying the average area and velocity. MIP (Medium Irrigation Project) was used to estimate mean monthly flows at ungauged sites. Nepal is divided into 7 hydrological regions, and the project location lies in Hydrological Region 1. Once the low-flow discharge measurement data is taken, long-term average monthly flows can be determined by multiplying the unit hydrograph with the measured catchment area according to the MIP Method. The criteria for the selection of design discharge were based on agro-technical considerations such as crop water requirement and command area.  

In addition to the design discharge, high flood design discharge was also taken into consideration. The catchment area of the river source was computed to be 50 square kilometers, and the highflood discharge was computed using five different methods. The average of these values obtained is taken into consideration, and regional analysis is adopted for high-flow calculations.  

This study aimed to design an irrigation project to provide water to the command area for crop cultivation. The study involved a joint walk-through survey and site investigation to identify river stability problems and high-risk zones for laying the pipe network. A focus group discussion was conducted to assess the agricultural situation of the command area.

Agro-economic data collection was carried out through household surveys and discussions with key informants. Crop water requirements and water balance were calculated using CROPWAT software and the mean monthly flow was determined using the MIP method.  

Cropping intensity was calculated to evaluate the extent of multiple cropping on the farm. Engineering design involved the design of major components such as the intake well, pump house, electrical accessories and fittings, transformer and power connection, sump well, pipe networks, distribution system, and protective devices. The economic analysis was undertaken with two major assumptions: a) the project life is 25 years, and b) the maintenance cost is taken to be 1% of the total investment cost, occurring from the second year.  

Sensitivity analysis was performed to assess the economic viability of the chosen irrigation project at several selected input scenarios. The analysis included examining the risks that occur when investment costs increased, incremental benefit shortfall, and when both investment costs increase and incremental benefit shortfall. The internal rate of return (IRR) and benefit-cost ratio (BCR) were applied in the economic analysis, and sensitivity analysis was carried out.  

Results and Discussions 

The study showed that the project is feasible as the lift height is 80 meters. The water balance was calculated and found that the crop water requirement meets the design discharge.   

Figure 1: Water Balance

From the figure in the horizontal axis 1, represents the January First half and 2 represents the Second half and is similar in the case of other months respectively It was found that for every half month, the mean monthly flow is excess, indicating that water is enough for the command area.  

The proposed project involves the construction of a lift irrigation system in Rangun Khola to provide year-round irrigation to the command area. Water is to be lifted from the river to an upper tank using an electrical pump and then distributed to the command area through a network of main pipes, sub-main pipes, and laterals. The pipes are made of GI and HDPE and have been designed based on the necessary discharge to effectively irrigate the command area. The farmers in the project area currently follow traditional subsistence practices of agriculture, with terraced agricultural lands and a moderate gradient. The existing cropping intensity is 130%, and the proposed Cropping intensity is 232% the irrigation facility will have an impact on increasing the intensity of crops and modernizing the cropping pattern with more valuable crops, which will further enhance the potential to achieve the expected benefits.  

The project has conducted a detailed item-wise rate analysis based on prevailing government approved norms and district rates. The analysis has also considered transportation costs to the rate of market materials at Dadeldhura or nearest, wherever it is available. The rate of labor and market materials are adopted from the district rate of Dadeldhura FY 2078/79.  

In terms of technical specifications, the capacity of the tank is 73.13m3 and the main riser is made of GI pipe (Medium class) of 80mm dia with a length of 900m. The total length of the main pipe is 750m, the sub-main 1100m, and the laterals 3800m.  

Figure 2: Sensitivity Analysis of the Study 

The lift irrigation project proposed for the command area near Rangun Khola is expected to cost NPR 15,136,000.00. The economic viability of the project has been evaluated using several parameters. The Benefit Cost Ratio (BCR) of the project at 10% and 12% discount rates are computed to be 1.91 and 1.66, respectively, indicating that the project is economically feasible. The Economic Internal Rate of Return (EIRR) of the project is computed to be 19.91%, which is considered good. The cost analysis also considered different scenarios, such as a cost increase of 10%, a benefit decrease of 10%, and a combination of both, and the BCR values were still greater than one in all cases, indicating that the project is viable. Overall, the lift irrigation project is expected to have good economic returns and would benefit the farmers in the command area.  

Conclusion  

The Bhabar Lift Irrigation Project aims to provide reliable lift and distribution systems to the area as it lacks any irrigation facility, leading to low productivity. To guarantee the successful implementation of the project, special attention needs to be paid to the following risk factors: extended or prolonged implementation, decreased or delayed benefits, lack of coordination between beneficiaries and government organizations, inadequate agricultural support programs, and inadequate operation and maintenance. Therefore, the institutional development aspects should be implemented from the beginning of the project, including beneficiary participation, setting up of Water Users’ Organizations, female participation in the WUAs, and setting up of a Steering Committee to coordinate the different aspects of irrigated agriculture.  

Overall, the Bhabar Lift Irrigation Project is technically feasible, economically viable, socially acceptable, and environmentally friendly. Thus, the project is recommended for implementation. It has the potential to not only increase productivity and benefit the farmers but also promote institutional and social development in the region.  

References   

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This is the web copy of an article that was originally published in the print version of '

The agrineer 2023' - Annual Magazine.