SWURVE - Uncertainty, Risk and Vulnerability in Lake Regulation Operations for Lake Morat, Bienne and Neuchatel in Switserland

This SWURVE Case Study on Lake Regulation Operations looked at a complex hydrological system of three interconnected lakes (Neuchatel, Bienne and Morat, Switserland) on the northern side of the Alps formed 15,000 years ago. Two 'water corrections' (1833-1884 and 1963-1972) have been carried out and different regulation waterworks have been built, in order to reduce the risks of inundation and transform unproductive areas into fertile arable land. The end-user for this study is the reference institution for all the topics related with water management and measurement. One of its major activities is to keep a close watch over river planning (for example: hydropower operations). All the projects submitted to this body must take into account all the involved interests (economical, social, environmental). Moreover, they control the water release of the weir. There are a number of modes of failure of the system which will be investigated, including:

- Lake level above a critical level because of above-normal input. Potential consequences are water logging of agricultural areas, flooding of agricultural land and urban zones, and inappropriate conditions for fauna and flora on the riparian areas
- Lake level below a critical level because of droughts. Potential consequences are inappropriate conditions for aquatic fauna in lakes and flora on riparian areas, insufficient irrigation water, daily hydroelectric production target not achieved.

If a failure occurs for one regulation user, its cost may be obtained thanks to a level-costs relation (dependent of season).