The starting situation was a private initiative of construction of a new residential sector, permitted by the current urban regulations, in a peripheral natural space of agro-forest use up until that time:  the Valley of Can Carreres.The announcement of the new construction caused a reaction in the form of a citizen's movement which organised a civic platform for the defence of this threatened natural space.  The citizens' claims coincided with the conclusions of the Local Agenda 21 participation forum, that during the same year recommended carrying out a study of the environmental, scenic, patrimony, and didactic values of the Valley of Can Carreres, and of other natural spaces in similar urbanism situations.

Faced with the conflict of interests, the City Council took the initiative to modify the foreseen urban planning, achieving an accord with the ground owners, reaching a consensus with the civic commission and planning a new strategy:  growth within the urban ground as an alternative to the occupation of the free ground. The positive impacts have been the introduction of environmental studies prior to the urbanism projects, the participation of the citizenry, and the signing of agreements for the solution of conflicts, the change of part of the private homes to public housing at social prices, and the public acquisition of the natural space of the Valley of Can Carreras as a definitive guarantee of protection.The local administration has learned that it may convert a situation of conflict into an opportunity to reconsider the future that it can put into place strategies, with the support of the citizenry, in order to adapt urban planning to the sustainable development requirements of the municipality.