The bell-mouth design is engineered to manage overflow water safely while preventing debris from blocking the tunnel intake.
The entire tunnel system linking the lakes was constructed manually by workers in the mid-1950s.
The spillway is rarely visible in its 'draining' state, as it requires water levels to be high, typically following heavy winter or spring snowmelt.
The structure is part of a complex hydro-system that diverts water from the high-altitude plateau to feed lower-lying power generation facilities.
Covão dos Conchos is a spillway located in the Serra da Estrela mountains of Portugal, characterized by its distinctive 'funnel' appearance that appears to drain the lake into the earth. The spillway is a bell-mouth intake built in 1955 as part of the Hydroelectric Power Station of Sabugueiro. It connects via a 1,519-meter-long tunnel to the Ribeira das Naves, channeling water to the Lagoa Comprida reservoir. The structure itself is built from concrete and granite, measuring 4.6 meters in height with a 48-meter circumference at the top. The effect of the water disappearing into the center occurs when water levels rise sufficiently to overflow the lip of the concrete funnel. It is situated at an elevation of approximately 1,900 meters within the Serra da Estrela Natural Park.
The western edge of the spillway, which allows for a clear view of the funnel intake against the backdrop of the reservoir.
Wear sturdy, waterproof hiking boots as the surrounding terrain is uneven, rocky, and often muddy.
Bring layers, as high-altitude weather in the Serra da Estrela changes rapidly regardless of the season.
Check local weather reports for the Serra da Estrela; visibility often drops significantly due to dense mountain fog.
Attempting the hike during winter months without specialized mountain gear or when snow coverage is high, as the trail is poorly marked and dangerous in low visibility.
Stay on marked trails to protect the fragile alpine vegetation and maintain respect for the designated nature park area.
