The Waduk Buatan built by the government in the 80s is a reservoir for the Ambang and Merbau watersheds located in Lembah Sari Village, Rumbai Pesisir District, Pekanbaru City, which was initially used as a source of irrigation water for the surrounding area's rice fields, which was later converted into a PDAM raw water source. The basic contour of The Waduk Buatan is needed to determine the ma…