Hydropower and Residual Flow
Status Quo on the Enforcement of the Residual Water Regulations of the Swiss Water Protection Law (Part 1)
The Swiss Water Protection Law (in force since 1992) also regulates the minimal residual flow for all watercourse sections which are influenced by hydropower plants. All hydropower plants which received a concession before 1992 must be restored to guarantee a minimal residual flow (article 80 ff). A renewal of a hydropower concession and an implementation of a new hydropower project must match article 29 ff.
The project aimed to get a comprehensive overview on the present implementation state of the Residual Water Regulations 15 years after the enforcement in 1992 and to develop and discuss various options how to proceed. To summarize, the responsible authorities face major challenges to implement these regulations. Mainly comprehensive political will and economical and compensational aspects are real issues.
The project was carried out by an interdisciplinary project team: The Swiss Greina Foundation outlined the judicial aspects and discussed options how to arrange the compensation payment for the communities. Eawag was primarily responsible for an overview on the implementation state of the Residual Water Regulations and highlighted scientific and ecological issues (see report). The results of the project are intended to provide a basis to experts, politicians, communities and further interested people.
Download (in German):
- Wasserkraftnutzung und Restwasser - Standortbestimmung zum Vollzug der Restwasservorschriften [pdf, 1.2MB]
Visualisation of River Sections of Residual Flow and Need of Restoration (Part 2)
The new revised Swiss Water Protection Law was implemented in January 2011. One task is to define river restoration needs on cantonal level. Therefore it might be interesting to get a geographical overview of all river sections with residual flow in Switzerland.
The Eawag map which shows all river sections with residual flow reveals an overview on the implementation state of the Residual Water Regulations in 2004. This map categorises the river sections of actual residual flow compared to the minimal residual flow according to the Swiss Water Protection Law in Article 31.1. The data are shown in a map of Switzerland on a scale of 1:900’000 (pdf) as well as divided into four parts on a scale of 1:500’000 (pdf). The methodology and the most relevant results are summarized in a report. This Eawag map can be considered as a completion to the report of Part 1 of this project.
This map reveals that in 375 river sections (28% of all 1318) no or only very little water flows after withdrawl (category red). For 645 river sections (49%) there are no complete data available (category grey). We can assume that a substantial amount of this river sections also do not have any residual water.
Download (in German):
- Documentation [pdf, 3.8MB]
- Swiss Maps of River Sections with Residual Water Flow:
1:900'000 [pdf, 2.2MB]
north-eastern part of Switzerland 1:500'000 [pdf, 1.2MB]
north-western part of Switzerland 1:500'000 [pdf, 0.6MB]
south-eastern part of Switzerland 1:500'000 [pdf, 1.6MB]
south-western part of Switzerland 1:500'000 [pdf, 1.4MB]