In recent, we have a growing interest in the washland construction for the satisfaction of flood mitigation
and ecological function in the river. This study performed the flood mitigation analysis for washland construction
plan in Topyoung-cheon basin in Changyeong-gun, Gyeongnam. Several cases were considered for the washland
construction on Topyoung-cheon basin, and we analyzed flood stage, inundation and flood damage mitigation for
each case. From the result of flood mitigation analysis, we found some significant results according to the
combination of each washland case and form. Therefore, to maximize flood mitigation effect by flood mitigation
analysis is more desirable than guarantee the maximum storage area in washland construction.