The hydro-environmental projection corresponding to water resources availability in the major Korean multipurpose dams based on the IPCC climate change scenario(A1B) is suggested. The projection by 2040 for precipitation and dam inflow gives 7.8~13.1% and 6.7~24.6% increase. The inflow projection for 7 major dams shows highest increasing ratio of 24.6% in Chungju and lowest of 6.7% in Juam, and 13.6% increase on the average under the Foreseeable Future scenario. The dams (Soyanggang and Chungju dams) in Han river basin shows relatively higher increasing trend than the dams in the other regions, Nakdong river basin in particular. As a result the availability of surface water resources can be expected to be improved, but, at the same time, the vulnerability against flood risk can be aggravated. The hydro-environmental impacts are lowest in Juam. Sediment impact is expected highest in Soyang. Total-Phosphrous impact is relatively low in most areas, but highest in Imha.