Plans to construct a dam in Tanay municipality have been proposed since the late 1970s, during which the first feasibility studies were conducted, partly supported by the World Bank. The project, then termed Manila Water Supply III Project, became soon after known as Laiban dam, due to its location in Barangay (village) Laiban. It was to be designed and implemented under the responsibility of the Metropolitan Waterworks and Sewerage System (MWSS) . However, the project became soon controversial due to its impacts on the Sierra Madre primary forest ecosystems and indigenous communities, who opposed the project since the beginning. In the years to come, the Laiban dam was several times approved, deferred, canceled and reapproved (for a detailed chronological overview see ).