Analysis of the Effective Length of Handil Channel for Tidal Irrigation at Palingkau Irrigation Area in Central Kalimantan Province for National Food Estate Program

Abstract

The handil irrigation system is a traditional water management system developed by local farmers and the government to irrigate rice fields using tidal power for supply and drainage. The canal with a width of 25 meters and a length of about 2 kilometres was developed to irrigate 1,397 ha of irrigated agricultural land in the Palingkau Irrigation Area. At high tide, freshwater enters the canal from the Kapuas Murung River, and drains into the river at low tide. After a long period of development of the area, sediment deposition and changes in channel cross-section occur so that the water system does not function optimally. For the sake of rehabilitation, an analysis was carried out to determine the effective canal length of the canal that is influenced by tidal water, considering channel capacity, tides and land elevation. Hydraulic analysis was performed by using HEC-RAS mathematical modelling. The results showed that tidal fluctuations could not irrigate two handil’s rice fields out of 8 existing handils. Canal rehabilitation in the form of increasing channel capacity is carried out by considering the length of the canal and the irrigation area irrigated, including its effect on improving water quality.