The Ganges-Kobadak (G.K) Irrigation Project as conceived in the early fifties was the first major step in Bangladesh to provide supplemental irrigation to traditional rice varieties. It is the largest lift-cum-gravity irrigation system in the country. Like other irrigation projects in Bangladesh, the performance of this project is much below the potential level. Inadequate funding for the proper maintenance led to gradual deterioration of the physical infrastructure. In addition, problems such as lack of practical guidelines for main system operation, lack of measuring devices for water distribution and allocation, lack of control at the main system level, and excessive use of water by farmers in locations with easy access to water lead to poor performance level.
Between 1985 and 1994, the G.K Project was under rehabilitation with a loan from the Asian Development Bank (ADB) and Technical Assistance from UNDP to address the above deficiencies. The lesson learned is that changes to the physical works (the hardware) are relatively straightforward and can be accomplished in a reasonably short time span, whereas changes to improve the management, operation, and maintenance (the software) of the system are less straightforward and difficult to accomplish in a limited time span (Burtonand Frank 1989). In this paper, the discussion is made on the aspects of software changes in rehabilitation for efficient irrigation management with sustainable operation and maintenance procedures.
DESCRIPTION OF THE G-K IRRIGATION PROJECT
The project area is located in the southwestern part of Bangladesh. The G-K Project Kushtia Unit comprising two phases was taken up for implementation in 1954. The net irrigable area is about 125,000 ha. Phase-I consisting of about 42,000 ha was implemented during 1954–70 and Phase-II covering an area of about 83,000 ha was completed during 1969–83. A typical monsoon climate prevails in the project area. The average annual rainfall is about 1,600 mm, about 70 percent occurs during mid-June through mid-October. Rice is the dominant crop occupying about 70 percent of the total cropped area. Pulses, oilseeds, jute, sugarcane, tobacco, and wheat are the other important crops. The Ganges-Kobadak Irrigation Project derives its water from the Ganges River.
The project includes two major pumping plants, flood control, and drainage facilities, and an irrigation distribution network comprising main, secondary, and tertiary canals. Irrigation water is pumped from the Ganges River by the main pumping plant having 3 pumps of 36.8 cusec capacity and also by a subsidiary pumping plant having 12 pumps of 3.54 cusec capacity each. The project’s main canals are about 193 km, secondary canal about 467 km, and tertiary canal about 995 km, in length. The area has developed because of the project.
Good crop production is assured as areas are free from floods and have more or less assured water supply for irrigation. In irrigated areas mainly High Yielding Varieties (HYVs) of paddy are grown. At present, about 93,000 ha are benefiting from supplement irrigation during Kharif-II season (mid-July – mid-November), against the targeted area of 125,000 ha, while about 25,000 ha are irrigated during the Kharif-I season (March – June) due to scarcity of water. In contrast to other areas in Bangladesh, no irrigation is supplied for the winter crops (November to February) at present. However, pulses, oilseeds, onion, wheat, tobacco, etc. are cultivated in large areas (about 60%) under residual moisture conditions during this season.
PROJECT ORGANIZATION AND SYSTEM OF OPERATION
The Ganges-Kobadak Irrigation Project is operated and maintained by the Bangladesh Water Development Board (BWDB). Under BWDB, the organization of the G.K. Project has a straightforward structure, where a Superintending Engineer (Project Director) is the head of the Project with Executive Engineers in charge of the Divisions. Divisions are responsible for construction and O&M in the field. For agricultural development activities, an extension unit has been established. The extension staff is primarily responsible for the agricultural extension, water management at the field channel level, and for the guidance of the water management association. The extension staff works under the administrative control of the Project Director and under the technical control of the Chief Water Management of BWDB.