Assessing the environmental benefits of multi-purpose water uses of hydropower reservoirs on the Han River in South Korea

The South Korean Government is trying to implement multi-purpose water uses of six hydropower reservoirs on the Han River to strengthen the linkage between water and energy. The expected environmental improvements are an improvement in flood control, an increase in the water supply for environmental improvement, an increase in the water supply for the instream flow requirement, and the abatement of air pollutants and greenhouse gas emissions. This article aims to value the four improvements by applying a choice experiment. For the purpose of reflecting the preference heterogeneity, by investigating the choice experiment data gathered from a survey of 1000 people, a Bayesian estimation of a mixed logit model is employed. The environmental benefits of a 1% improvement in flood control, a 1% increase in the water supply for environmental improvement, a 1% increase in the water supply for the instream flow requirement, and a 1% abatement of air pollutants and greenhouse gas emissions are estimated to be KRW 71 (USD 0.06), 51 (0.05), 28 (0.03), and 77 (0.07), respectively, per household per year. The expected improvements for the four attributes are 25.2%, 17.7%, 17.7%, and 1.0%, respectively. Thus, the expected environmental benefits are worth KRW 3265 (USD 2.96) per household per year and the national value amounts to KRW 63.74 billion (USD 57.77 million).