The Àrea Metropolitana de Barcelona (AMB; "Metropolitan Area of Barcelona") is a public body operating on the principle of metropolitan authority. It is composed of representatives of Barcelona and 36 adjacent municipalities accounting for a population of 3,239,337 (Idescat, 2014) within an area of 636 km2. Its jurisdiction constitutes the main core of the unofficial Barcelona metropolitan area, with a population over 5 million. Executive Bodies The three executive bodies are: Mancomunitat de Municipis (Union of Municipalities): Covering 31 municipalities, it manages common services affecting public spaces, infrastructure, facilities, urbanism and housing for 3,029,389 inhabitants in an area of 495 km2. Given the range of services it offers, it is often construed as the core of the AMB. Entitat del Transport (Transport Authority): Covering 18 municipalities, it serves a population of 2,790,803 in an area of 332 km2. These make up the strict Barcelona conurbation. Created to jointly manage public transport within its area. Entitat del Medi Ambient (Environment Authority): Covering 33 municipalities it serves a population of 3,121,795 in an area of 583 km2. Entrusted with water supply and waste management for the area. Powers Territorial The AMB is responsible for three areas: territorial planning, urban planning and infrastructures of metropolitan interest. Territorial planning Participation in the preparation and proceeding of the general territorial Plan of Catalonia. Participation in the preparation and monitoring of the partial territorial plans that affect its area and the sectoral territorial plans that affect its powers. Preparation of plans, charters and programmes for the protection, management and planning of landscape. Urban planning Integrated urban planning of the metropolitan territory by means of the Metropolitan Urban Master Plan (PDUM) and the Metropolitan Urban Planning Plan (POUM). The AMB is responsible for the initiative for the formulation and initial and provisional approvals of both plans and their subsequent amendments. Participation in the Urban Planning Commission of the Metropolitan Area of Barcelona. Formulation and approval of the initial and provisional pluri-municipal urban development programmes. Formulation and approval of derived planning elements having metropolitan interest or affecting several municipalities. Urban management of the PDUM and the POUM as a competent and acting Administration. Protection of urban legality by delegation of municipalities or replacement of municipal authority. Exercise of sanctioning powers, where appropriate. Cooperation and legal and financial support to municipalities concerning with planning, action programmes, projects and works, and urban discipline. Metropolitan infrastructure Execution and management of infrastructure