Eyes on the Aging Fagilde Dam in Viseu: How Comfortable Should We Be by 2029?

Fagilde Dam, which has been holding water on the Dão River since 1984, is today the lifeline of approximately 150 thousand people living around Viseu, Mangualde, Nelas, Penalva do Castelo and Sátão. However, this structure, which has been around for 40 years, has recently been talked about more for its safety than for the water itself.

The new dam is aimed to be completed by the end of 2029; This means that the region is entrusted to the current body for at least three more years. At this point, only one question comes to mind: How long and with what safety limit will the current dam remain standing?

Wear and Discharge Capacity of Concrete Raises a Question Mark

The National Civil Engineering Laboratory (LNEC) has actually been following Fagilde step by step for more than twenty years. Reports from 2021 and later make clear that internal sulfate reactions in concrete lead to expansion and serious cracks.

There is another dimension to the work that is not limited to the body alone: ​​The flood discharge channel of the dam is insufficient to meet the extreme flood conditions required by current regulations. Past events such as the overflows in 1995 and 2000, and the malfunction of a valve in 2007 and the uncontrolled discharge of 1.3 million cubic meters of water, remain fresh in our memories. The main reason why the new dam decision was taken approximately 100 meters down is this lack of evacuation.

What Engineers Say, What Do Local Government Want?

The Ministry of Environment and expert engineers state that the situation is being closely monitored and there is no imminent danger of collapse. According to structural engineers, seeing cracks or material fatigue in a dam does not directly mean that it is "unsafe"; With sensors and regular checks, the structure can remain in operation as long as critical thresholds are not exceeded.

Viseu Mayor João Azevedo rightly expects more concrete answers. He emphasizes that while there are findings of "serious structural abnormality" on the table, the government must draw a clear safety boundary: What are the warning thresholds that will require reducing the capacity of the dam, is there an emergency plan ready to be activated if things deteriorate faster than expected?

The foundation of the new dam will be laid in 2028 and we will have to keep our eyes on Fagilde until the construction is completed.

Source: Expresso, Natasha Donn

Image Source: Paulo Novais / Lusa