The tertiary level irrigation system in the Punjab region of Pakistan is facing a significant challenge due to the loss of irrigation water. It has been established that around 40% of irrigation water is lost in the century-old community watercourses due to poor maintenance and aging. This situation is not only detrimental to the agriculture sector but also results in the wastage of a precious resource.
To address this issue, the maintenance of the watercourses needs to be improved. Regular cleaning, desilting, and repair of breaches are some measures that can be taken to prevent water loss. Technology can also play a crucial role in detecting and monitoring water losses, such as the use of sensors to detect leaks and blockages.
The government needs to provide funding and establish a mechanism to monitor and maintain the watercourses. Community-based organizations can also be involved in the maintenance of the watercourses, with incentives provided to those who maintain them well. The involvement of farmers in the maintenance of the watercourses can also lead to greater accountability and responsibility.
Efficient use of water resources is critical for sustainable agriculture and the conservation of a precious resource. Therefore, addressing the loss of irrigation water in the tertiary level irrigation system in Punjab is essential. The use of various stakeholders and technology in the maintenance of watercourses can help address this issue and lead to sustainable agriculture practices.
Causes of Water Losses
The tertiary level irrigation system in the Punjab region of Pakistan is facing significant water losses due to several factors. The main sources of these losses are seepage, spillage, and side leakage from the watercourses, which can be attributed to the following reasons:
- Irregular profile and zigzag alignment of banks with many points of weakness
- Variable cross section of water channels
- Silt deposition causing restrictions in flow and overtopping
- Trees, shrubs, and vegetation growing in watercourses
- Damage caused by rodents and farm animals
- Frequent bank cutting and plugging for water abstraction
The irregular profile and zigzag alignment of banks with many points of weakness are significant causes of water losses. This is because the watercourses' structure is not uniform, leading to weak points that allow water to escape. The variable cross-section of water channels is also a contributing factor to water losses as it can lead to restrictions in flow and overtopping, resulting in spillage.
Silt deposition causing restrictions in flow and overtopping is another reason for water losses. When silt accumulates, it restricts water flow, leading to overtopping and spillage. Trees, shrubs, and vegetation growing in watercourses are also responsible for water losses, as they obstruct the water's flow and contribute to spillage.
Damage caused by rodents and farm animals is a significant cause of water losses in the tertiary level irrigation system. Animals can damage the banks, leading to seepage and spillage. Frequent bank cutting and plugging for water abstraction are also causes of water losses, as this can weaken the structure of the watercourses, leading to seepage and spillage.
In conclusion, the water losses in the tertiary level irrigation system in Punjab can be attributed to several factors, including irregular profile and zigzag alignment of banks, variable cross section of water channels, silt deposition, vegetation growth, damage caused by animals, and frequent bank cutting and plugging. Addressing these factors through maintenance and repair of the watercourses is crucial to conserve water resources and ensure sustainable agriculture practices.
Process of Watercourse Improvement
Watercourse improvement or renovation is a crucial step towards conserving water resources and increasing agricultural productivity in the tertiary level irrigation system in Punjab. The process involves the complete demolishing of the community channel and its rebuilding/re-aligning according to engineering design, which reduces seepage, evaporation, and operational losses. The following are the steps involved in the process of watercourse improvement:
- Demolition of existing channel: The existing watercourse is completely demolished to create a new structure that aligns with the engineering design.
- Rebuilding and realignment: The new watercourse is constructed and aligned according to the engineering design to improve conveyance efficiency and reduce water losses.
- Installation of water control structures: Water control structures such as gates, weirs, and regulators are installed to control the flow of water and improve conveyance.
- Lining of watercourse: The watercourse is lined to reduce seepage and evaporation losses. The standard "Pucca" lining is commonly used, which consists of double-brick masonry walls (23 cm) and a brick masonry bed (7 cm) plastered inside and on top of the walls. However, other types of lining, such as pre-fabricated concrete, pipe, and plastic, are also used, depending on the farmers' choice, field conditions, and cost-effectiveness.
- Pre-cast parabolic lining: Currently, the lining with precast concrete parabolic segments (PCPS) is being used under all development projects. This design has proved to be durable and easy to install.
- Watercourse improvement is a complex process that involves several steps. However, it is necessary to conserve water resources and increase agricultural productivity. The use of modern technology, such as pre-cast concrete parabolic segments (PCPS), can make the process more efficient and effective.
|
|
Installation of Nakkas
Installation of precast "nakkas" is an essential part of watercourse improvement and renovation to reduce channel deterioration, seepage loss, and improve water control. The following are the steps involved in the installation of nakkas:
- Installation of precast "nakkas": Precast "nakkas" are installed at all authorized places to reduce channel deterioration, seepage loss, and to improve water control. They considerably reduce drudgery in irrigation operation.
- Provision of nakkas: Under normal conditions, where the land is fairly leveled and belongs to one or two farmers only, the standard practice of providing one nakka (turnout and check) for every 25 acres is quite satisfactory. Extra provision of nakkas is, however, made where the land has been subjected to fragmentation because of uneven topography, repeated division of ownership, social problems, etc.
- Construction of culverts: Culverts are constructed at major crossings to ensure proper water flow.
- Provision of additional structures: A limited number of checks/drop structures, animal wallows/buffalo baths, and laundry sites are provided as required to improve the efficiency of the irrigation system.
- Public health benefits: The construction of washing places and lining of reaches through villages gives additional public health benefits.
The installation of precast "nakkas" is an important step towards reducing water losses and improving the efficiency of the irrigation system. It not only benefits farmers by reducing drudgery in irrigation operations but also improves public health.
Selection Criteria
The selection criteria for watercourse improvement and renovation have been adopted to ensure maximum benefits to the farmers while minimizing costs. The following criteria are currently being followed:
- Condition of watercourse: Watercourses that have not been previously improved or lined below 50% of the total length are given priority for improvement.
- Willingness to form a WUA: Farmers are required to form a water users association (WUA) and agree with the cost-sharing arrangements before initiating the improvement work.
- Reconstruction of katcha portion: Shareholders must agree to reconstruct the katcha portion of the watercourse before commencement of the lining work.
- Sections to be lined: The following sections of the watercourse are selected for lining:
- Head reaches having maximum usage and flows are given priority to improve conveyance efficiency.
- Elevated sections that are susceptible to leakage, overtopping, and spillage are also given priority for lining.
- Portion of the watercourse that crosses, passes through or along villages, and roads are also selected for improvement to reduce public health hazards and road damage.
- Sections having sandy/porous soils are also given priority for lining.
The above criteria ensure that watercourse improvement is carried out in a systematic and efficient manner while maximizing the benefits to the farmers. It also helps in reducing water losses and improving the overall irrigation system.
Cost Sharing Arrangements
The cost sharing arrangements for watercourse improvement involve the government providing the entire cost of construction materials and technical guidance. Meanwhile, beneficiary farmers contribute the entire labor costs for improving unimproved watercourses as well as completing improvement works on partially improved watercourses. The specific labor costs that farmers contribute include:
- Demolishing and reconstruction of katcha watercourse
- Excavation for the portion to be lined
- Back earth filling of structures and lined section
- Masons and unskilled labor for all civil works
By dividing the costs in this way, the burden of the project is shared between the government and farmers, making it more feasible and sustainable.
 |
Impact of Watercourse Improvement
The watercourse improvement program has had a significant impact on the irrigation system in Punjab, Pakistan. The following are some of the positive outcomes of the program:
- Water saving: The program has resulted in an annual water saving of 229 acre feet in regular watercourses, 164 acre feet in additional watercourses, and 55 acre feet in irrigation schemes.
- Increased cropping intensity: There has been a 9% increase in cropping intensity, allowing for more agricultural production.
- Improved crop yield: Crop yield has increased by 31%, resulting in higher profits for farmers.
- Reduced theft and amicable dispute resolution: The program has reduced water theft and improved dispute resolution among farmers.
- Improved equity: The program has promoted equity among farmers by ensuring that everyone has access to an adequate water supply.
- Economic benefits: The program has resulted in an annual production gain of PKR 3 million per watercourse, benefiting the local economy.
- EIRR: The estimated internal rate of return (EIRR) for the program is 42%, indicating its financial viability.
Procedure for Obtaining OFWM Application Form
To obtain the application form for the On-Farm Water Management (OFWM) facility, applicants can follow the following steps:
- Visit the office of Deputy Director Agriculture (OFWM)/Assistant Director Agriculture (OFWM) in person and request an application form.
- Download the application form from the official website of OFWM.
- For additional information or queries regarding the application process, applicants can reach out to provincial, divisional, district, and tehsil level OFWM offices. The OFWM website also provides useful information on the application process.
- Fill out the application form with accurate information and attach all required documents.
- Submit the completed application form to the relevant authorities. The concerned officials will review the application and determine the eligibility of the applicant