Irrigation water economic valuation for irrigation water tariff basis

This research is intended to develop economic instruments to increase water use efficiency in the agricultural sector on the island of Lombok. In the short term, this study aims to analyze the availability and demand of season-based and commodity-based irrigation water, estimate the economic value of irrigation water resources both surface water irrigation and groundwater irrigation, determine the optimal amount of commodity-based irrigation water contributions, and analyze the factors expected to influence its implementation. Trend Analysis and Residual Imputation Approach (RIA) are used to analyze water demand and estimate the economic value of water. The results showed that the availability of water determines the cropping patterns applied in the study area. The upstream area has a pattern of planting rice for three growing seasons or paddy-paddy-palawija. Then in the middle area paddy-paddypalawija or paddy-paddy- horticulture and Paddy-palawija for downstream areas. Food crops grown include corn, soybeans and peanuts. The contribution value of water in creating the production value of rice, corn, soybeans and peanuts amounted to Rp. 1581/m(3) (Rp. 14 720 691 /ha), Rp. 372 / m(3) (Rp. 2 611 812 / ha), Rp. 693/m(3) (Rp. 2 235 618/ha) and Rp. 1501/m(3) (Rp. 4 762 673 / ha).