Offsetting for a hydropower project in Costa Rica

We supported ICE (Instituto Costarricense de Elecricidad) in their biodiversity risk management through application of the mitigation hierarchy, developing metrics for loss/gain accounting and an offset plan for averted loss of river Natural Habitat.

The project in question is the Proyecto Hidroeléctrico Reventazón Hydropower Plant (HPP) affecting the Reventazón River, a medium-sized, flowing into the Caribbean. As a result, the Parismina River was identified as equivalent to the Reventazón River (like-for-like) and now no HPP will be developed on the Parismina River in the future. This is an averted loss offset.

Most hydropower projects are likely to have residual impacts that require offsets to reach international leading practice standards (e.g. IFC PS6). The Reventazón HPP has pioneered the use of metrics to plan no net loss with the Parismina River Offset, setting a best-practice standard for other HPPs in Costa Rica and globally. This is perhaps the first direct offset of the impacts of a HPP on a river ecosystem, demonstrating that no net loss HPPs are feasible under certain conditions. However, it is important to highlight that no net loss is much more feasible for certain HPP designs and environmental conditions, e.g.:

• Run-of-the-river, rather than storage
• Upstream in the watershed, rather than downstream
• Downstream of existing HPP
• Base-load energy production rather than peak-load
• Small reservoir area
• Toe of the dam powerhouse, rather than distant with a long dewatered length of river

Photograph is copyright hydroworld.com