The pressure compensation tower at Chôdes is connected to the reservoir at Robertville by an underground water supply line 5.5 km in length. In accordance with the physical principle of communicating vessels, the water level in the tower remains the same as that in the lake. Above the ground, the tower rises to a height of 38 metres – making its overall height 64 metres – and it has a diameter of 8 metres. A pressure line feeds the water from the tower into the hydroelectric power station in Bévercé, which lies 154 m lower down and, with its 3 turbines, produces 23,000 kWh of electrical power each year. That corresponds to the quantity used by approximately 7,000 families. The purpose of the compensation tower is to regulate the pressure of the water. This helps to prevent a potential wave of excess pressure (known as water hammer) from forming, which would cause damage in the pipe, when the 3 turbines are brought to a quick stop. The hydroelectric power station complex Robertville-Bévercé was built between 1925 and 1930. Apart from producing green electricity, these facilities also provide drinking water for the town of Malmedy and ensure flood control downstream of the Warche for the prevention of high water in Malmedy.
