The Verzasca Dam, originally named Contra Dam, is the fourth largest dam in Switzerland, located in a deeply incised narrow gorge in Canton of Ticino, in the district of Locarno.
The Verzasca Valley is not only home to one of the most popular dams in the world, but is also known for its clear and refreshing waters surrounded by stunning wilderness, destination for many travellers.
The dam, located at the beginning of the Valley, has allowed the formation of a large artificial lake while offering a natural setting for one of the most famous action scenes of the history of cinema: GoldenEye.
According the global surveys, Bond's leap from the Verzasca dam is considered the best stunt in film history. And the ultimate adrenaline rush at Lago di Vogorno is also called 007 Jump or GoldenEye Bungee Jump.
The lake is called Lago di Vogorno which has a 105,000,000 m3 (3.7×109 cu ft) capacity and surface area of 160 ha (400 acres), collected from a catchment area of 230 km2 (89 sq mi). The Verzasca River has very irregular seasonal flows which can reach as high as 1,000 m3/s (35,000 cu ft/s).
On May 6, 1960, Verzasca SA was formed to construct the dam as the center-piece of the Verzasca Hydroelectric Complex.
Construction began in 1961. The dam was designed and its construction supervised by Lombardi & Gellaro Ltd.
Because the Contra Dam is at a lower elevation compared to other Swiss dams, warmer weather allowed construction to be carried out year-round.
To divert the river and prepare a dry work-site for the dam, cofferdams were constructed, one of which redirected the river through a diversion tunnel with a 200 m3/s (7,100 cu ft/s) capacity.
As the river can have flows much higher than the tunnel's capacity, this was accepted as a risk by engineers.
The aggregate for the concrete was obtained from a quarry near the construction site.
A grout curtain was placed around and below the dam as well to prevent leakage, which consumed a large amount of cement.
In August 1964, the reservoir began to fill and in September 1965, the reservoir was full and the dam completed.
The Contra Dam is a concrete slender arch dam with a height of 220 m (720 ft) and crest length of 380 m (1,250 ft). The dam is 25 m (82 ft) wide at its base and 7 m (23 ft) wide at its crest.
The dam structure contains 660,000 m3(23,000,000 cu ft) of concrete and the structure itself has a surface area of 44,500 m2 (479,000 sq ft).
The structure is slender in design and its horizontal arches are in an elliptical shape. The curvature of the dam decreases from the center of the dam towards its abutments and the curvature from the center of the arches increases from the crest down to the foundation.
The thickness is constant with the exception of where the dam is received by its abutments; here it is thicker to reduce pressure on the rock. The strong rock can accept stresses of 70 kg/cm2.
Vertically, the thickness of the dam increases from the crest down to the foundation and has a slight curve from the center towards the crest. This helps alleviate tensile stress for when the reservoir is not only full but empty.
The dam's outlet works consist of two discharge pipes, capable of releasing up to 170 m3/s (6,000 cu ft/s) each. One discharges into the original diversion tunnel and another is located at the base of the dam and discharges into the river valley below.
Lombardi considers it one of his most aesthetically pleasing dams, primarily because of the slenderness of the concrete arch and the "outstanding cleanness of the design." The design also reduced the amount of concrete needed, therefore reducing the cost as well.
The dam supports a 105 MW power station that contains 3 x 35 MW Francis turbines and generates an average of 234 GWh annually. Water from the reservoir at 470 m (1,540 ft) above sea level is transferred to an underground power station downstream at 193 m (633 ft) above sea level, affording a maximum hydraulic head of 277 m (909 ft).
The power plant can discharge up to 50 m3/s (1,800 cu ft/s) of water which exits via a 1.9 km (1.2 mi) tailrace tunnel into Lago di Verbano.
As I mentioned at the beginning, the dam is famous for being the second biggest bungee jump in the world, after the one from the Macau Tower, in China.
A permanent jump platform is installed on the dam.
The leap into the void lasts 7.5 seconds, plus a strong shot of pure adrenaline.
There are four jump options.
007 CLASSIC JUMP
The 007 Classic Jump is the famous 007 jump from the GoldenEye film.
It is ideal for those who do bungee jumping for the first time, or at least for beginners.
The Backwards Jump, which can be combined as a second jump to the 007 Classic Jump, is suitable for expert jumpers or those who want that extra adrenaline rush compared to the classic jump.
The Night Jump, possible only on certain specific days, is a unique experience, to try if you want something different from the simple jump in day light.
You jump with your hands holding a special elastic, in a standing position (head up and feet towards the bottom of the dam).
The 007 Ultimo Jump is recommended only for experienced jumpers and it is only possible as third jump after the 007 Classic Jump and the Backwards Jump.