Alonso Miguel opens works for Minimisation of Hydrological Risks in Grota da Lagoinha - Communication

Secretaria Regional do Ambiente e Ação Climática

The Regional Secretary for the Environment and Climate Change, Alonso Miguel, opened today the works for the minimisation of hydrological risks in Grota da Lagoinha, Terceira island.

Alonso Miguel stated that this is "a relatively simple but strategic intervention, since, together with other interventions promoted by the Regional Government and this department, such as the redevelopment of Ribeira da Vinha Brava stream, also already completed, it aims to implement effective and technically adequate solutions to minimise flooding risks in the city of Angra do Heroísmo."

The Regional Secretary for the Environment and Climate Change explained that "flood events in the archipelago are generally caused by flash floods, as a result of very intense rainfall, which is becoming increasingly frequent due to the effects of climate change. This is one of the areas of the city of Angra do Heroísmo that has been most affected by this type of phenomenon in recent years, causing overflows and floods in the grounds of the São Rafael Mental Institutions and in the ring road."

Alonso Miguel explained that "the water of two hydrographic sub-basins flow into this area, which is the reason why this work comprised two separate interventions."

"With one of the interventions, the aim was to reduce the flow of solid flows in the drainage sub-basin that ends at the rainwater collector located at the back of the São Rafael Mental Institution, which drains the water from pastures upstream. In this case, the solution involved the construction of a retention basin for solid flows and damping of liquid flows, so as to allow the drainage of flows through the collector without exhausting its flow capacity," he clarified.

The Regional Secretary added that the second intervention "aimed to solve the flow of water in the drainage sub-basin that ends near the house that existed in the Ponta do Muro area, which was acquired and demolished by the Angra do Heroísmo City Council. It drains the water from the land to the west of the São Rafael Mental Institutions, which, under certain conditions, flooded the outer ring road of Angra do Heroísmo."

"In this case, we opted for the construction of an infiltration well with an approximate capacity of 800 m3, which allows the collection of rainwater, with the conduction of the flow to this well being carried out, in a first phase, through a canal built with pipes and, in a second phase, after the retention of solid material in a transition basin, through a reinforced concrete canal to the well," continued the government official.

Alonso Miguel also mentioned that "the construction work represented an investment of the Regional Government amounting to approximately 370 thousand Euros, with a completion period of 142 days. In fact, it is a very relevant intervention to mitigate natural hazards, namely overflow and flood events, thus improving the conditions for safeguarding the population and protecting property."

The Regional Secretary thanked the Angra do Heroísmo City Council and the São Rafael Mental Institution for their collaboration in these works, namely for providing the necessary land for that purpose.