Ponds for irrigation

At present only 400 thousand ha area i.e. 15 per cent is irrigated a year round in Nepal. Irregular rainfall pattern is affecting farmers day by day. It is essential to guarantee irrigation facilities throughout the year. Conservation ponds or water harvesting are best alternative in this scenario where water is limited. It is a fine alternative in the mid regions of Nepal where irrigation is difficult during dry periods. Conservation ponds have huge efficiency in collecting rain water and preventing excessive erosion and surface runoff down landslide slopes providing habitat for fish raising. Water from ponds may be used for crop establishment, seasonal water requirements and to fulfill irrigation needs. To reduce seepage from earthen pond, plastic lined ponds works in our fields. High density polyethene sheets are recommended for lining. Building ponds in shady places helps in minimizing evaporation losses. Irrigation of small gardens in the dry period is a big advantage that too helps in maintaining aesthetical view. In dry seasons, it helps in reducing the amount of time housewives are provided to fetch water. They can be of different shape and size to meet one’s needs. It can be built using local tools and materials with implementation of local manpower.

Ponds are the basic form of reservoir. It should be located where the largest storage volume can be obtained. Lakes generally are used for flood irrigation whereas ponds typically enhance sprinkler and drip. Ponds can be filled up by various phenomenon i.e. rainfall, runoff and even diverting water from streams. Providing small part of land for pond construction helps  fulfill the farmer’s need and watershed management. Farm ponds are also beneficial for fish farming, watershed management and landscape beautification. The size of ponds depends upon land availability, needs of farmers and slope considerations. Pond bed depends on seepage rates with replacement frequencies i.e. plastics, stone, clay. It is important that it contains diversion waterway to pass surplus water into stable area.

Tearing of plastic, damages of pond bank, intake damages are common problems we are facing. Deep sheeted erosion, mass wasting, seismic shocks are the risks we cannot ignore during its construction and maintenance.

Source selections, operation technology, reparability, workmanship are used to determine the functionality of pond irrigation.