The Mexican legal system

22.01Mexico is a federal democratic republic consisting of thirty-one states and the federal district of Mexico City, and governed by a civil law system. The main sources of law are (i) the Constitution, which is written; (ii) international treaties signed by the executive with the ratification of the Senate; (iii) federal laws passed by the federal Congress; (iv) state laws passed by state congresses; (v) judicial decisions; and (vi) jurisprudence.

22.02The constitutional reform of 1987 established a concurrent jurisdiction system according to which the federal and state governments share the power to legislate on environmental matters. Furthermore, in 1999 the federal Constitution was amended to recognise both the right of people to a healthy environment and the principle of sustainability. Notwithstanding the concurrent jurisdiction system, it is generally assumed that Article 27 of the federal Constitution, which regulates the property system that governs waters, land and natural resources, remains the main foundation for Mexican environmental law.