Survey, Design and Construction Supervision of the upgrading of Village Irrigation Systems in Sri Lanka

Mottapetthawa Cascade in Kurunegala District

The “Climate Resilience Integrated Water Management Project (CRIWMP)” is being implemented by UNDP, for improving the resilience of vulnerable communities in the dry zone of Sri Lanka, to climate change impacts with a special focus on drinking water. The Ministry of Mahaweli Development and Environment with the assistance of United Nations Development Programme in collaboration with the Department of National Planning, Ministry of Irrigation and Water Management, Ministry of Agriculture, Ministry of City Planning and Water Supply and Ministry of Disaster Management, secured financing from Green Climate Fund (GCF) to implement a 07 year project from 2017 to 2024 aimed at strengthening the resilience of smallholder farmers in the Dry Zone to climate variability and extreme events.

In the last few decades, irrigation systems and land settlements have been a principal investment strategy in Sri Lanka for achieving the national goal of self-sufficiency of food. The process of expanding the land area has been dominated by investments in the construction of new irrigation systems. Nevertheless, there remains a real risk of crop failure in dry years particularly in the areas irrigated under small tanks (minor reservoirs) which have been paid less attention compared to the mega irrigation projects. Although, a number of large reservoirs such as Kotmale, Victoria, Randenigla, Maduruoya etc. has been constructed in the late last century, network of small tanks still plays a major role in providing irrigation water to the paddy farms in the dry zone which contribute a considerable input to the national economy.

Thus, rehabilitation of neglected tank cascade systems which provide rural farmers their livelihood, and  contributes to the self- sufficiency of foods while providing much needed domestic water supply, is a very important & productive investment in the dry and intermediate zones.

The scope of the assignment is to provide the consultancy service for surveys and designs, construction supervision and quality assurance and managing defect-liability period in selected Village Irrigation Systems (VIS) located in Mottapetthawa Cascade.

This project envisages development/rehabilitation of existing Mottapetthawa Tank Cascade Systemin Galgamuwa DS Division, Kurunegala district, to make the farmer community under this tank cascade, more resilient to the droughts while mitigating the effect of floods up to a certain extent.

The Mottapetthawa cascade is situated in Galgamuwa DS Divisions in Kurunegala District. Cascade is situated entirely in the dry zone which is characterized by the existence of a large number of small tank cascades. Although the mean annual rainfall is around 1,500 millimeters, the 75 percent probability value is approximately 900 millimeters. More than 65% of the annual rainfall is experienced during Maha season.