This paper presents an example from the island of Mindanao in the Philippines, on how to involve community groups within a partnership of researchers, non-governmental organizations and government officials for assessing water quantity and quality within the 36 000 km2 Manupali River basin. The results of a survey conducted by the members of the communities themselves revealed a clear pattern of progressive land degradation that was closely associated with increasing population pressure and corresponding changes in land use (from forest to fire-climax grassland and subsistence cropping).
