Why Is the European Union Demolishing Dams?
Human beings have been using dams to bend lakes and rivers to their will for millennia. The first recorded dams in human history were built in ancient Egypt, sometime around 2950 BC. The European landscape is dotted with the same sort of engineering masterpieces, many of which are hundreds or thousands of years old.Why is the European Union demolishing some of these dams, and what impact will it have on the local environment in the future?
A Long Dam History
Hundreds of thousands of old dams dot the European landscape. They've been used for centuries for irrigation, generating power, and bringing potable drinking water to nearby cities, towns and villages. In spite of their utility, dams have almost always had some sort of negative impact on the rivers they divide. Flowing water becomes stagnant, and fish are unable to migrate as they once did. As a result, their populations start to decline.
This has been observed directly in recent decades. Parts of Spain's Huebra River near Yecla de Yeltes, was once home to small freshwater fish, otters, and black storks— all of which have suffered a decline in population since a dam was built in 1958. The dam no longer functions, but its negative effects remain.
Decades of Renewal
This isn't the first time the EU has made a move toward removing old or unused dams from its landscape. Dam Removal Europe estimates that some 3,450 small dams and other water-obstructing architecture were taken down in the last 20-25 years in Sweden, Spain, Portugal, the U.K., France and Switzerland. More than 1,200 dams were removed from U.S. rivers as well in the last couple of decades, with 86 removed in 2017.
Benefits of Dam Removal
Dam removal supporters cite multiple case studies that show removing these engineering marvels is good for the environment. It allows fish and animal migration to continue unobstructed, and promotes natural sediment flow that encourages biodiversity.
The upcoming removal of two dams in France — Vezins and La Roche qui Boit — will free up roughly 90 kilometers of the Selune River, allowing for salmon migration that has been impossible since the dams were built. It's estimated that upwards of 5,000 salmon will be able to return to the river once the dams are removed.
Not All Positive
Not all the effects of dam removal are positive, and many people are calling for investigations into the impact of these projects before they are completed. There are concerns that by removing the dams, engineers could be creating a higher flood risk for downstream towns and villages, as well as potentially damaging bridges or other infrastructure.
Sediment buildup in the areas above the dams could also be a problem. Removing the two hydroelectric dams that block the Elwha River in Washington state is expected to cloud the river with sediment for up to three years. This could decimate local fish populations before the sediment settles or moves downstream by clogging their gills and eventually killing them.
Removing dams from natural waterways could potentially hold a great number of benefits — as long as the negative effects are also taken into account before demolition begins. Both Europe and the United States could greatly benefit from the restoration of their waterways. These rivers and streams are already among the most diverse ecosystems in the world, and clearing upstream obstructions could help restore them to their former glory.