Acquisition of Neuchâtel gas pipeline

In December 2007, Unigaz SA acquired the high-pressure gas pipeline commissioned by Gansa in 1979, thus enabling gas to be supplied to the canton of Neuchâtel and the Pontarlier and Morteau region (France).

Consolidation of the western part of the Lake Geneva area

The Trélex – Colovrex gas pipeline was officially opened on 9 May 2014 to consolidate security of supply for Western Switzerland and respond to growing demand for natural gas in the Geneva region.

Click here to see the explanatory video about the construction of the Trélex – Colovrex gas pipeline (in French)




Founding of Gaznat

Gaznat was founded on 12 March 1968 in the form of a research company working towards the introduction of natural gas to Western Switzerland.

Creation Gaznat

Minutes of Gaznat’s first board meeting


Supply company

In 1974 Gaznat became a separate company for the purpose of supplying natural gas to Western Switzerland. In the same year, its first gas pipeline came into operation. Its transport network then developed in six phases.



The Gazoduc Suisse Romand (GSR) [Gas Pipeline of Western Switzerland]


The Gazoduc Suisse Romand (GSR), which came on line in 1974, is a gas pipeline originally built to carry natural gas from Bex (at the end of the Rhone gas pipeline) to Vernier. It was laid along the bottom of Lake Geneva with landfall points at Vevey, Lausanne-Vidy, Tolochenaz, Gland and La Gabiule (in the municipality of Collonge-Bellerive). From there, the gas pipeline travelled back across the lake to exit at Le Vengeron, completing its route at Vernier. A further land-based branch started at Tolochenaz and interconnected at Orbe.


Gazoduc sous-lacustre

Click here to view the Video of how the pipeline was laid on the bottom of Lake Geneva (5’24”, in French)

Full video of how the pipeline was laid on the bottom of Lake Geneva (16’27”, in French)


First interconnection with France

In 1977, the La Gabiule – Annemasse gas pipeline is built to supply the Annemasse region by Gaznat until the link to the Savoie main pipeline was operational. In 1986, upon completion of the aforementioned link to the Savoie main pipeline, Gaz de France starts to give back to Gaznat the gas that was supplied during the past ten years to the French area. 



Founding of Unigaz SA

In 1979, in partnership with the company Gasverbund Mittelland AG (GVM), which owned 40% of the shares, Gaznat founded the company Unigaz SA in order to develop the Orbe – Mülchi gas pipeline, which fed into the Transitgas pipeline near Staffelbach via the Swissgas pipeline.



The Transjura gas pipeline between La Cure and Gland was added to the network. This gas pipeline also linked up with the gas storage facility at Etrez (France) and the north-south gas pipeline of Gaz de France (the natural gas transport network operator at that time, now GRTgaz).


Ruswil – Altavilla

In 1994, Unigaz SA constructed the Ruswil – Altavilla gas pipeline, which connected directly to the international transport route operated by Transitgas.


A second gas pipeline beneath the lake

In 1995, Gaznat laid a second gas pipeline beneath the lake, between Les Grangettes and Gland, with landfall points at Clarens, Lausanne-Bellerive and Tolochenaz.


Third interconnection with France

The St Julien – Vernier gas pipeline, which provided a second point of entry from France, was constructed on the Savoie main pipeline.


Created on 12 March 1968, Gaznat celebrates its 50th anniversary in 2018. 


Click here to discover the explanatory historical video about Gaznat's developement (FR)

Gaznat 50


logo Gaznat

Gaznat changes the color of its logo, but its company slogan remains the same: "Our energy, your future".