Environmental Impact Assessment (EIA) is a fundamental preventive instrument in Portuguese spatial planning. In a context where economic development must be balanced with the protection of natural resources, EIA emerges as an essential mechanism to ensure that projects and activities are implemented in an environmentally responsible manner.
This guide addresses the central aspects of the EIA process in Portugal, from identifying projects subject to assessment through to the final decision-making phases. Understanding this process is crucial for project promoters, consultants, and public authorities involved in project approval.
When is EIA Mandatory in Portugal?
In Portugal, the requirement to conduct an EIA is regulated by Decree-Law 151-B/2013. This legislation establishes two categories of projects subject to assessment:
Annex I — Always Mandatory: Large-scale projects, such as refineries, thermal power stations, dams higher than 15 metres, motorways, ports and airports, among others. For these projects, EIA is imperative, regardless of their specific characteristics.
Annex II — Subject to Screening: Includes smaller initial projects, such as transport infrastructure, manufacturing industry, agricultural or tourism projects. For these, the requirement depends on a screening analysis, which weighs criteria such as location (sensitive areas), magnitude, environmental characteristics and potential impacts.
The Water and Waste Authority (APA — Autoridade da Água e Resíduos) is the competent entity to coordinate the EIA process at national level, although in some situations this is decentralised to regional authorities.
Phases of the EIA Process
The EIA process in Portugal is structured in several well-defined phases:
Scoping (Pre-EIA): The project promoter submits an initial request to the competent authority, which defines the scope of the assessment. In this phase, the environmental factors to be studied, the project location and potential impacts to be evaluated are identified. This phase is crucial for establishing the technical foundations of the study.
Preparation of the Environmental Impact Study (EIA): Based on the scope definition, a comprehensive technical document is prepared that characterises the project and analyses its impacts across various environmental domains. This study is fundamental to decision-making.
Public Consultation and Citizen Participation: The EIA is made public for 30 days, allowing citizens, environmental organisations and public bodies to contribute observations and concerns. This phase is essential for transparency and legitimacy of the process.
APA Decision (Environmental Impact Declaration): After analysing the EIA, public contributions and technical opinions, the APA issues an Environmental Impact Declaration (DIA — Declaração de Impacte Ambiental), which is binding. The DIA can be favourable (with or without conditions) or unfavourable, and is an essential document for obtaining subsequent licences.
The Environmental Impact Study (EIA)
The EIA is the central document of the assessment process and must include mandatory minimum contents established by law:
Analysis of Alternatives: The study must present alternatives to the proposed project, including the zero alternative (non-execution of the project), and justify the choice of the selected alternative based on environmental, technical and economic criteria.
Characterisation of the Baseline Situation: A detailed description of the existing environment (climate, geology, biodiversity, landscape, water resources, population) before project implementation. This baseline is fundamental for evaluating future changes.
Impact Assessment: Systematic analysis of how the project will affect each environmental factor, considering construction, operation and decommissioning phases. Impacts are classified according to their significance, magnitude and duration.
Mitigation and Compensatory Measures: Proposal of actions to avoid, reduce or compensate for negative impacts. These measures must be technically and economically viable and monitorable over time.
A high-quality EIA is built by a multidisciplinary specialist team and must be rigorous, transparent and scientifically credible.
The Role of the Environmental Consultant in EIA
The environmental consultant plays a strategic role throughout the EIA process:
Coordination of Multidisciplinary Teams: The consultant leads specialists in different fields (ecology, hydrology, landscape, social aspects, etc.), ensuring a holistic analysis of the project and technical coherence of the EIA.
Interface with APA and Public Bodies: Acts as an intermediary between the promoter and authorities, preparing technical documentation, responding to regulatory queries and coordinating submission of materials.
Schedule Management and Technical Quality: Ensures that the timetable is met, mandatory contents are present and the technical and editorial quality of the study is impeccable, increasing the likelihood of a favourable DIA.
An experienced consultant in EIA processes is essential to navigate regulatory complexity and ensure that the project progresses efficiently.
Conclusion
Environmental Impact Assessment is a robust instrument for ensuring that development in Portugal is environmentally sustainable. Understanding the phases of the process, technical requirements and the role of the different stakeholders is fundamental to the success of any project subject to environmental assessment.
If you are planning a project that may be subject to environmental assessment or wish to optimise your EIA process, specialist consulting can make the difference. Get in touch with us to explore how we can support your project from the initial phase through to obtaining the Environmental Impact Declaration.
