ABSTRACT The OSAKA Irrigation Area (DI) in Rokan Hulu Regency, Riau Province, is an important area in supporting local agricultural productivity. This study aims to analyze the performance of the main dam structures (Kaiti Dam, Pegadis Dam, and Samo Dam) as well as the supply channels in the OSAKA Irrigation Area, based on PUPR Regulation No. 12/PRT/M/2015. The methods used include field …