Modernisation of rainwater management on the Meyrin site: future work and accompanying measures

In line with the cantonal objectives designed to improve the discharge regime and water quality of the Nant d'Avril, CERN is modernising the way that rainwater is managed on its Meyrin site. A site-specific list of actions is included in the regional wastewater management plan (Plan Régional d'Evacuation des Eaux, PREE) for the Nant d'Avril, which was validated by the Council of State in July 2014.

A hydrological study carried out in 2017 by a specialist engineering firm confirmed the relevance and necessity of structural work to reduce the impact of run-off on the regional water system.

Reinforced infrastructure

Several measures will be gradually implemented on the Meyrin site:

• Construction of a 3000-m³ underground retention basin, reusing the old SIG tanks located beneath the Building 41 hostel (permit pending).
• Creation of an open-air retention basin measuring around 1000 m³, close to the main rainwater collector for catchment area 2, at the end of the Route Greinacher car park.
• Systematic integration of rainwater management systems into all new projects on the site: on the roofs, on the surface or underground, as appropriate.

Start of work in the Greinacher car park

Work on the open-air retention basin in the Greinacher car park started on 10 March.

85 parking spaces will be unavailable for the duration of the work, including 56 that will be permanently removed. This is in addition to the spaces that are temporarily unavailable due to the renovation work currently under way on Building 100.

Accompanying measures and mobility

A coordinated set of measures is planned to limit the impact of the reduction in the number of parking spaces.

Measures in progress or to follow

• Launch of a survey of occupants of the Meyrin academic area.
• Opening of the hostel (B39) car park: + 45 spaces.
• Introduction of a driverless shuttle from April onwards, increasing the frequency of the circuit 1 service.
• Addition of 30 electric bikes for CERN's bike-sharing scheme.
• Promotion of sustainable mobility solutions, including public transport serving the site, sustainable transport infrastructures, car sharing on the CERN site and park-and-ride car parks.
• Optimisation of the planning for various worksites, in terms of both space and time, to limit the impact on parking at any given moment.

Measures under study

• Revision of parking regulations in the academic area in order to prioritise essential needs and optimise the use of available spaces.
• Adjustment of long-stay and short-stay parking areas to free up spaces and facilitate access to the buildings concerned.
• Increased communication with users via internal channels and temporary on-site signage.

The aim of all these measures is to support the CERN community during the work, while also contributing to more sustainable mobility management on the Meyrin site.

Thank you for your understanding.