The SEIA is a preventive environmental management instrument that allows the authority to determine before the execution of a project if:

Complies with current environmental legislation
Takes responsibility for potential significant environmental impacts
The main function of the Environmental Assessment Service (SEA) is to administer the Environmental Impact Assessment System (SEIA).

The SEIA entered into force on April 3, 1997. More than two decades after its application, the SEIA has allowed the country to achieve a substantial change in the way of building the future, by being able to prevent the impacts that the public and private investments, or ensure that, when significant adverse impacts are generated, there is mitigation.

Link