Solid waste management (SWM) has become a continuing hurdle for governments and communities because of its multi-faceted nature. With the worsening SWM problem, the Philippines enacted Republic Act 9003, the Ecological Solid Waste Management (SWM) Act 2000, instituting SWM Program. Water quality in water bodies and watersheds is adversely affected by pollution, exacerbated by increasing population and urbanization. This study examined RA 9003 implementation in urban and rural communities of Santa Cruz Watershed (SCW) which drains into Laguna Lake. Knowledge, awareness, and perceptions (KAPs) of communities were elicited using focused group discussions, interviews, and surveys in barangays within the watershed. Municipalities have completed respective10- year SWM Plans, organized SWM Boards, and SWM committees in villages. Communities showed satisfaction with SWM implementation and monitoring but rural communities had higher overall SWM effectiveness ratings. Both communities were willing to pay for a cleaner environment. Challenges that hamper better implementation of RA 9003 include non-segregation of solid waste by residents attributed to lack of awareness and discipline; irregular garbage collection; inadequate garbage trucks; lack of functional materials recovery facilities; and limited government resources. Addressing these concerns will further boost RA 9003 compliance and enhance the effectiveness of implementation and monitoring in the communities.