Watershed management is critical to sustain the benefits from the development of small water storages or small dams in Barani Areas, said Asian Development Bank's experts.
In a project review report on "Watershed Management Constraints in Barani Areas", Sedimentation Surveys of sample dams in the Pothowar region reveal that loss in water storage capacity can be as high as 4.2 percent per year, which could lead to full siltation of the dam's dead storage after 24 years.
Empirical evidence also demonstrates that a few dams are likely suffering from higher sedimentation rate. The impact that this premature loss of effective storage would have on the dams' beneficiary communities, even beyond the dams' economic life, needs attention.
In particular, an assessment of the watershed condition and any needed management plan should be studied at the feasibility stage and monitoring and control of erosion in the dam watershed must be ensured after dam construction. In recent small dam development projects undertaken by Punjab Irrigation and Power Department (PIPD), watershed management components have been included to address the issue of sedimentation.
Although long-term studies have not yet been possible, the initial results of watershed management activities on small dams demonstrate the feasibility of the approach and its integration into the development of small dams in Barani Areas.
PIPD has recognised that, for small dams to achieve their full potential, more effective command area development needs to be put in place. In 2005, PIPD initiated the pilot project-command area development of small dams in Rawalpindi division.
This project covers the command area of four existing small dams and provides funds for agricultural extension, research, and the formation of village organisations for farmer support. The approach of the program recognises that it is vital to work in partnership with communities if farming practices are to change; ideally, however, strong community participation must start at the very beginning and continue throughout the dam development process so as to generate ownership and expedite productivity gains.
The PIPD program primarily focuses on agricultural support services, Small Dams Organisation (SDO) is supposed to repair the irrigation system and strengthen warabandi practices in the dams, yet their capacity and incentives to do that are limited. In addition, this pilot project does not form farmer organisations for ongoing management and O&M of the command area. While initial results have been positive, the approach still needs to be reflected in general policy and mainstreamed into regular practice for the development of small dams under Small Dams Organisation.
Commenting over the "Water Management Constraints", ADB experts stated that the agricultural benefits anticipated to be generated by small dams have not materialised due to both the failure to adequately prepare the irrigation distribution system in the command area, but, more importantly, the failure to prepare farmers to take full advantage of the new water supply. In general, Small Dams Organisation puts much of its technical emphasis on construction of the larger structures, the dam and feeder canal to the command area.
In the development of most dams, they said that the distribution network has received limited or no development. Given the small size of the distribution systems and the proximity of the water supply, improved design and operating procedures that are more demand-responsive may be possible and could improve yields as well as increase water use efficiency.
ADB experts said that watercourse development below the mogha (outlet) is left to the discretion of farmers since this activity traditionally falls under the purview of the Directorate of Command Area Development (DCAD) within the Department of Agriculture. In the larger Indus River irrigation systems, DCAD is generally quite active and engaged; however, it is generally not involved in the development of small dams, and watercourse and field channels are inadequately developed. They explained that the Federal Government is funding a special initiative for lining the watercourses, and to date, none of these funds have been channelled for the development of the command area of small dams.
This presents a significant problem since due to the small size of the small dam irrigation systems, watercourses and field channels are often the primary distribution features of their command areas. In addition, adequate land preparation for irrigation is generally absent, and small dam command areas are often in undulating terrain. Another reason for slow development of irrigated agriculture in small dams is that farmers do not generally practice warabandi (rotating water distribution at the field level where farmers are allocated specific time duration for drawing irrigation water for their fields).
The warabandi turn is essentially the farmer's water entitlement as specified in the Punjab Irrigation and Drainage Act of 1873, which is still the overarching policy document for irrigation in Punjab. The lack of rotation and the resulting often inequitable distribution may be due to inadequate attention given to warabandi development during construction of the dam or due to weak institutions for irrigation management with no irrigation rules for O&M that could be followed.