Agenda 21 is a global programme based on the concept of Sustainable Development. The three pillars on which it is based are: Economic viability, social inclusion and the responsible use of natural resources and together the Agenda fulfills the needs of the present and the coming generations.

The Global Agenda 21 programme was officially launched at the United Nations Summit for the Environment and Development in Rio de Janeiro city in 1992 (Rio Eco `92). Brazil elaborated its National Agenda 21 in 2002 and since then Brazil’s Ministry of the Environment has encouraged the elaboration of regional Agendas 21.

In 2003, the Ministry of the Environment funded the elaboration of Cachoeiras de Macacu municipality`s Agenda 21. REGUA established a formal partnership with its Cachoeiras de Macacu municipality. Eleonora Pacheco, Regua´s Environmental Education coordinator was the mentor of this initiative. Together with a team of professionals, they were in charge of the making of the socio-environmental analysis which produced the Agenda 21 Action Plan envisioning the sustainable development of the municipality through many meetings with the local population over the course of two years. The local Agenda 21 Forum was instated through a municipal law passed in 2009. In 2007, the Brazilian oil company Petrobras announced the construction of its biggest oil refinery (COMPERJ) in neighbouring Itaborai municipality. A joint force constituted by Petrobras, the Federal Ministry of the Environment, Rio de Janeiro Environment Secretariat and members of the 15 Petrobras refinery directly impacted municipalities, elaborated an even larger Agenda 21 COMPERJ which was published in 2010.

REGUA has a seat at the Agenda 21 Forum which in turn is part of the wider net of Agendas 21 called ComARC which include Cachoeiras de Macacu, Casimiro de Abreu, Guapimirim, Itaborai, Magé, Maricá, Niteroi, Nova Friburgo, Rio Bonito, São Gonçalo, Saquarema, Silva Jardim, Tanguá and Teresópolis municipalities.