The Kankai Irrigation System (KIS) has an office in Gainde, Jhapa district, Nepal's Province No. 1. The KIS weir type headworks is located in Domukha, Jhapa district, about 3 km north of the E-W highway Kankai Bridge at Gainde. The debouching point of the Kankai River from the slope to the terai plain was chosen as the diversion weir site. The Kankai River, a tributary of the Ganges River, is the KIS source river. The Kankai River, which originates in Nepal Mahabhrat Range, is classed as a second-class river. It meets the Mahananda in the Kishanganj district of Bihar, India, during its flow.

The Kankai Irrigation Project (KIP) was originally developed as an initial stage of agricultural development in the Kankai River Basin to irrigate about 5000 ha of existing farm land, leaving a potential of total 10000 ha of paddy land to develop in the near future using year-round irrigation facility. The KIS was constructed in two phases. The first phase of construction was administered by the then Kankai Development Board (KDB) under His Majesty Government of Nepal (HMG/N) from October 1973 to June 1980 at a cost of US$ 3,786,959 from the Asian Development Bank (ADB) and the national budget of the then HMG/N to develop a command area of 5000 ha. Under first phase of development main canal of KIS is divided into for reaches as Reach-I, Reach-II, Reach-III and Reach-IV depending upon topographic coverage. The second phase development began in year 1980 and accomplished in year 1991, adding command area of 3000 hactares from Reach-V of main canal. As a result, the total command area developed in two phases in five reaches in KIS is 8000 ha, facilitating for year-round irrigation of paddy farmland.

Kankai Irrigation System runs with a 10.15 cumec intake capacity at Reach I and gradually flows 36 kilometers over the main canal from -I to R-V. It would flow 74 kilometers through 22 secondary canals named S-0 to S-22, as well as 130 kilometers through 315 tertiary and direct tertiary canals. It is continually irrigating 8000 hectares of land in four palikas of Jhapa district: Shivasatachhi, Kamal, Gauradaha, and Gaurijung. Kankai Irrigation System is now managed by Kankai Irrigation Management Office under the MOPID of province 1 with the cooperation of Kankai Canal Water Users Association.