Laiban dam is a proposed bulk water supply project of the Philippine Government slated for construction at Barangay Laiban in Tanay, Rizal, on the upper portion of the Kaliwa River Watershed. It is intended to relieve Metro Manila of its overdependence on the water supplied by Angat Dam. Due to controversies regarding the project's environmental impact and its potential effect on local communities, notably including a community of Remontado Dumagat people who consider the area part of their ancestral lands, the project has remained controversial and has thus been alternatingly approved, deferred, cancelled, and reapproved by the Philippine Government at different times since the late 1970s.
The most recent proposal to proceed with the construction of the dam was in 2012, as part of the original scope of the New Centennial Water Supply Source Project proposed by the Metropolitan Waterworks and Sewerage System (MWSS). Upon recommendation of the National Economic and Development Authority (NEDA), however, the Laiban Dam component was removed from the approval request, and the new project was approved by the NEDA Board on May 29, 2004 as the New Centennial Water Source-Kaliwa Dam Project, with the Kaliwa Low Dam slated for more immediate construction and use, and the Laiban Dam and Laiban Hydro Electric Powerplant components intended for later construction as part of an integrated system.
The Laiban sub-watershed site
The Laiban site where the project is supposed to be built is a Barangay of municipality of Tanay in the province of Rizal, east of Metro Manila. It contains he 180 ha Laiban sub-watershed, a microbasin of the bigger Kaliwa Watershed, nestled in the southeastern portion of the Sierra Madre Mountain Range.
The Kaliwa Watershed forms part of the Sierra Madre Biodiversity Corridor (SMBC), and has been identified by the Southern Sierra Madre Wildlife Center of the Environmental Studies Institute of Miriam College as one of the SMBC's 14 priority biodiversity conservation sites. It is described as "an important wildlife habitat that contains dipterocarp trees, a wide array of birds, mammals, amphibians and reptiles, some of which are threatened and endemic species."
In 1999 the Kaliwa Watershed, evaluated at the time as "degraded due to anthropogenic pressures", was classified as a protected area under the National Integrated Protected Areas System.
The terrain is generally mountainous, surrounded by slopes > 50%, consisting partly of forested hills and partly of cultivated land, with some slash and burn cultivation (kaingin) areas present. Its elevation is from 220 masl (meters above sea level) to 1,530 masl. A number of small creeks run through the lower slopes, all eventually connecting to the main river.
The village also serves as home to the indigenous Remontado Dumagats.