The construction of new hydroelectric plants, especially those incorporating a reservoir, causes the flooding of land used for various purposes. The most significant impacts are the irreversible removal of high ecological value riparian galleries, the resulting habitat fragmentation and the change in flow regimes, causing the potential disruption of aquatic ecosystems.  In the reservoir zone, lotic (flowing water) systems are replaced by lentic (standing water) systems, which leads to an adjustment/replacement of resident species. Migratory species of fish are usually the most affected along the stretch of river where the dam is built.


What we do

> We implement measures for a new equilibrium in ecosystems, taking advantage of the favourable conditions for some species created by the dam, such as greater food availability.

> We promote compensatory measures such as the recovery of neglected water courses and the construction of small weirs to stabilise water height.

> We promote compensatory measures for habitat fragmentation, such as improving the quality of neighbouring habitats in order to ensure sufficient scale for the local survival of the affected species.  EDP has been adopting these measures in the new hydroelectric projects.

> We promote compensatory measures such as artificial spawning and the recovery of downstream water courses. EDP has fish ladders at many hydroelectric dams. It has been promoting compensatory measures associated with migratory species, has fish ladders currently under construction and is also undertaking studies to improve existing ones.

Find out more here.

The environmental impacts of thermoelectric power stations affect biodiversity in a more sporadic or indirect manner. Overall, the effect of climate change is considered one of the main threats to biodiversity. On a regional and local level, thermoelectric power stations nowadays have very tight regulations to ensure that the carrying capacity of the recipient environment is not exceeded, particularly in relation to acidic gas emissions, such as NO_x and SO₂ (responsible for acid rain) and cooling water emissions into the water environment, which may contribute to its heating up and the consequent imbalance of the recipient environment.

Indirectly, the impact arising from activities in the value chain can also be considered, the life cycle of electricity and gas in this case. With an installed thermoelectric generation capacity of 7,941 MW (coal, fuel oil and natural gas), the impact on biodiversity can be significant during the raw materials’ extraction phase, owing to the degradation of habitats that this extraction implies.


What we do

> We promote the reduction of electricity consumption generated from fossil fuels. EDP is committed to reducing CO₂ emissions by 70% by 2020, compared to 2005 figures.

> EDP has been choosing fuels with lower sulphur concentrations and implementing emissions’ denitrification and desulphurization systems.

> We promote the construction of cooling towers.  EDP periodically monitors this situation and the new combined cycle power stations have been built with cooling towers.

The impact on biodiversity by wind power generation is localised and small. However, it is an area of special focus for EDP since it is a swiftly expanding business area, and it is important to verify potential cumulative impacts. The principal direct impact on biodiversity arises from birds and bats colliding with the turbine blades. The location of the wind farms, mostly in remote areas, requires the opening of new roads which in turn attract local populations, adding to the disturbance of ecosystems.


What we do

> Studies to monitor bird and bat collisions with wind turbine blades. These have shown that the effect is lower than initially expected. It is necessary to evaluate these impacts cumulatively.

> We promote compensatory measures to limit arbitrary access roads that disturb sensitive species and habitats.

> We promote the mitigation measures that are detailed here.

The expansion of the electricity supply grid is very dependent on urban planning. As the construction areas in protected nature zones grows, the number of kilometres of power lines that have to be built in these regions also increases. The main impacts on biodiversity resulting from the electricity distribution activity are the collision and electrocution of birds on the Iberian Peninsula. Such impacts are extended to include other species of fauna in Brazil, such as the white-headed marmoset (Callix geoffroyi).

The need to manage the vegetation along the power distribution line buffer strips requires the periodic cutting of the vegetation. These measures must be based on sustainable interventions so as not to have a negative impact on habitats.


What we do

> EDP promotes mitigation measures such as route diversions, the use of insulated cables, the installation of signalling devices on power lines, besides many others that can be found on page 36 of the 2009 Biodiversity Report.

> We promote the insulation of overhead power lines.

The species potentially affected by EDP’s activities and the associated mitigation and/or compensation measures can be found in:

> Portugal;
 
> Spain;
 
> Brazil;
 
> Romania;
 
> United States of America.