In this section you will learn about the most common definitions and objectives of EIAs, together with a brief history and examples to illustrate why EIAs are important. This will help you to gain a basic understanding of the purpose of EIAs to guide the next steps.

What is an EIA?

Central America

An environmental impact assessment (EIA) is commonly described as an assessment of the impact of planned activities on the environment, including impacts on biodiversity, vegetation and ecology, water, and air.

An environmental impact assessment (EIA) is commonly described as an assessment of the impact of planned activities on the environment, including impacts on biodiversity, vegetation and ecology, water, and air. An EIA can be seen as a process of identifying, predicting, and evaluating the likely environmental, socioeconomic, cultural and other impacts of a proposed project or development to define mitigation actions—not only to reduce negative impacts but also provide positive contributions to the natural environment and well-being.

Essentially, an EIA is designed to identify the potential risks of a project (e.g., infrastructure development such as a dam) to environmental and human well-being and identify measures to eliminate and/or mitigate these risks. This can be done by replacing and/or modifying planned activities to reduce impacts. In this context, an EIA can be seen as an information-gathering activity by the project lead to outline (and if possible quantify) the risks, impacts and mitigation actions built into the project’s whole lifecycle from design to closure so that decision makers are fully informed when approving the project.

EIAs are carried out in a wide variety of sectors, including agriculture, manufacturing, tourism, mining and forestry. Projects requiring an EIA can be large, such as a hydroelectric dam, or small, such as a new hotel on a beach. However, the level of impact on human and environmental health—rather than the size of the project—is the most important aspect of decision-making on the need for an EIA.

Currently, over 100 countries have legislation mandating the implementation of an EIA when a development/project is deemed to potentially have considerable impacts on environmental and social contexts, including nearly every country in North, Central and South America. In some countries, there is also an indirect mandate for EIAs—e.g., if the project is supported by development banks such as the World Bank and the Inter-American Development Bank, these organizations require EIAs as a condition for financing the proposed project.

Central AmericaDefinitions and EIA mandate in selected countries in Central America

Country Definitions and EIA Mandate
Belize Instrument to identify and evaluate the effects of specific developments and to recommend mitigation measures.
Costa Rica Technical Instrument with a format defined by National Environmental Technical Secretariat (SETENA) and signed by the developer. Instrument describes activities, works, and projects, the environmental impact and the required prevention, mitigation, and compensation measures.
Dominican Republic Instrument for environmental policy and management that consists of procedures, studies, and technical systems to estimate the effects that works, activities, or projects may have on the environment.
Ecuador Instrument to prevent or minimize environmental damage caused by public and/or private investments. Ensures access for public officials and the public to relevant environmental information about a proposed project or activity prior to a decision on the implementation or execution of the activity or project.
El Salvador Ensures that activities, works, and projects follow procedures to identify and quantify impacts and mitigation measures.
Guatemala Ensures that activities, works, and projects follow procedures to identify and quantify impacts and mitigation measures.
Honduras To identify, predict and describe the possible positive and negative impacts of a project proposal, as well as, the proposed mitigation measures for negative impacts and a regular monitoring and control plan (Article 4.16 of ED189-2009). National Environmental Impact Assessment System (SINEIA) is also looking for the sustainable development of the country (Article 6 of ED189-2009).
Mexico Procedure to protect the environment, and avoid or reduce negative impacts by setting conditions for infrastructure projects or activities that could disrupt ecological balance, or violate established limits and conditions.
Nicaragua Administrative instrument consisting of procedures, studies, and technical systems for predicting the impacts of a specific work, activity, or project for which an environmental permit is being sought.
Panama Early warning system based on continuous analysis that enables preventive decision making to protect environment; required prior to beginning specified activities, works, or projects.

Source: Tiffer-Sotomayor et al., 2015

Why conduct an EIA?

Human well-being is closely connected to environmental sustainability.

Human well-being is closely connected to environmental sustainability. As a result, all forms of human development, such as building infrastructure (i.e., roads and pipelines, mines, and tourism facilities etc.) have an impact on the surrounding natural environment and vice versa. This is evident when we consider the results of large-scale development like open-pit mines, hotels for thousands of people and large hydroelectric dams that often have irreversible impacts on the environment and the livelihoods of people because of large-scale deforestation, excessive water use, habitat destruction and resettlement.

Because of the complex relationship between the natural and human environments, it is very important to try to predict the environmental and social impacts of programs, projects and planned developments that may alter the quality of the environment and impact well-being. As the human population continues to increase and natural resources become more limited, the importance of improving the sustainability of development and identifying mitigation measures—and thus the importance of creating high-quality EIAs—becomes greater.

What is the outcome of an EIA?

The final product of an EIA is an Environmental Statement or Report.

The final product of an EIA is an Environmental Statement or Report. The EIA report provides information to decision makers prior to issuing an operating licence so they can properly assess the project’s impacts on both the environment and people. Therefore, the report needs to be based on accurate and relevant information that accounts for diverse impacts and cumulative effects of the planned project’s life cycle. The ultimate audience of the EIA report is the decision makers: it aims to help them decide whether to accept the project as it is, ask for revisions in the project or reject it.

There are also wider outcomes associated with an EIA. It should lead to better standards of development, and in some cases, limit development completely in sensitive areas. Where developments do go ahead, environmental assessments should help propose proper mitigation measures. When done well, an EIA can help stimulate growth and production in the local economy while promoting sustainability.

What is essential in an EIA?

An EIA should allow decision makers to assess a project’s impacts in all its phases.

An EIA should allow decision makers to assess a project’s impacts in all its phases. It should also allow the public and other stakeholders to present their views and inputs on the planned development. Furthermore, to be truly effective, an EIA must contribute to and improve the project design, so that environmental as well as socioeconomic measures are core parts of it. Information used in the EIA needs to be based on good data, use accepted methodological approaches and be summarized in plain language that is understandable for decision makers.

Finally, the EIA does not end with the granting of a licence to operate. It is critical that that the approved practices and design are followed during the project operations and construction and that ongoing monitoring is in place during the lifetime of the project.

Essentials of EIA in Honduras

  • Applicable to all actions expected to have a significant environmental impact.
  • Presents two alternatives to compare to the proposed actions (including the possibility of not acting).
  • Makes clear the significance of probable impacts to experts and laypeople.
  • Includes broad public participation.
  • Programmed toward providing information for decision makers.
  • Includes monitoring and control procedures.

Source: UNEP, 2002; Friends of the Earth, 2005

What assessments are related to EIA?

Examples

Beyond EIAs, there are other types of environmental assessments that are used to identify and eliminate the harmful environmental impacts of projects, investments and other activities.

Beyond EIAs, there are other types of environmental assessments that are used to identify and eliminate the harmful environmental impacts of projects, investments and other activities.

  • Strategic Environmental Assessments (SEAs) (sometimes referred to as Environmental Assessments [EAs]): An SEA is a systematic decision-making process done to analyze the environmental and human health effects of a proposed development activity. This process is conducted prior to the environmental impact assessment and determines the EIA’s scope, depth of analysis and types of public participation and consultation to be integrated into the plan. Public participation and consultation are essential aspects of this process and should be integrated at every step of the EA process where possible (United Nations, 2012).
  • Integrated Environmental Assessments (IEAs): An IEA is a process of producing and communicating future-oriented, policy-relevant information on key interactions between the natural environment and specific human activities (IISD & UNEP, 2008).

Examples

There is increasing recognition in EIAs of the importance of assessing the social impacts and consequences of development projects and alternatives. This has been formulated in a standardized procedure called a Social Impact Assessment.

A short history of EIA

Since its beginnings more than 50 years ago, EIA has evolved from assessing only impacts on the natural environment toward integrating social and health impacts as well.

Since its beginnings more than 50 years ago, EIA has evolved from assessing only impacts on the natural environment toward integrating social and health impacts as well. EIA was first introduced into U.S. environmental policy in the 1960s. This served as a catalyst for many other countries, which began to implement EIA policy throughout the 1970s and early 1980s. The Organisation for Economic Co-operation and Development (OECD) and the European Union have been at the forefront of implementing EIAs internationally since the mid 1980s. The United Nations gave EIA a substantial push in 1992 through Principle 17 of the Rio Declaration, which emphasized the importance of EIAs as a “national instrument” to be used for all projects likely to have significant adverse environmental impacts and which are subject to the decision of national authority.

In Honduras, the principles of EIA were introduced in 1993 as the part of the the General Law of the Environment, adopted by Executive Decree No. 104-93. In 2009, legislation on the actualization and modernization of the EIA system was adopted as a Ministerial Agreement No. 189-2009 and published in the official newspaper. The 2009 EIA modernization legislation is currently applicable in Honduras. Sources: Gilpin, 1995; UN, 1992; UNEP, 2002; OECC, 2000 .

Learn more about EIA history – see the EIA Timeline if you have not done so already.