Modernized efforts for harnessing Nigeria‟s abundant water resources for municipal water supply; irrigation and power generation commenced around 1923 when the first earth dam was constructed. Subsequently many more dams were constructed in the 1970s during the oil boom. And presently more dams are built in a pattern described as a form of top down approach intervention or maladjustment that lacked proper planning; community participation that not only hinder optimal and efficient utilization of resources but threaten sustainability of the projects. Legal, institutional and policy framework / documents that evolved over time to create access, set standards and enforce regulations such as; the (Nigeria)Waterworks Act of 1915, the River Basin Development Authority (RBDA) Decree 25 of 1976 (1979 and 1987), the National Water Resources Master Plan, 1995, the National Water Policy 2004, National Irrigation Policy and Strategy for Nigeria of 2005 and the National Water Resources Master Plan 2013 among other legal/institutional and policy frameworks expounded on and intended to address challenges of water resources development and management in the Country. The aim of this paper is to present an appraisal of these policy and institutional framework in integrating or mainstreaming ecosystem based watershed management. We conduct a review of these frameworks. Our findings reveal that there is a paradigm shift from structural (engineering or hardware) approach to an integrated approach to water resources management that emphasized Ecosystem-Based Watershed Management. The most recent of these frameworks underlined the cross-cutting nature of water resources management and calls for synergy and collaboration, involving users, planners and policymakers at all levels through participation, and with coordination and technical competence of specialized basin entities or Ministries, Department and Agencies (MDAs) as well as research institutions, donor and development partners. The recommendations are geared towards improving cooperation and complementing efforts and commitments of the MDAs.