Preface

“Erosion, transport and deposition of sediment”

Case Study Rhine

________________________________________

Erosion, transport and deposition of sediment have significant economic, environmental and social impacts in large river basins.

The International Sediment Initiative (ISI) of UNESCO provides with its projects an important contribution to sustainable sediment and water management in river basins. With the processing of exemplary case studies from large river basins good examples of sediment management practices have been prepared and successful strategies and procedures will be made accessible to experts from other river basins.

The CHR produced the “Case Study Rhine” in the framework of ISI. Sediment experts of the Rhine riparian states of Switzerland, Austria, Germany and The Netherlands have implemented their experiences in this publication. Prof. Emil Gölz and Dr. Martin Keller of the German Federal Institute of Hydrology, Dr. Wilfried ten Brinke and ir. Emiel van Velzen of the former National Institute for Inland Water Management and Waste Water Treatment in The Netherlands, Dr. Jos Brils from the Dutch research institute Deltares and Dr. Alessandro Grasso from the Division of Hydrology of the Swiss Federal Office for Environment have provided valuable contributions for the publication, based on studies carried-out in the respective countries. The CHR secretariat under the guidance of ing. Eric Sprokkereef has prepared the printing of the publication.

On behalf of the CHR coordinators I thank the institutions and experts involved in the preparation for the provided excellent contributions.

Prof. Dr. Manfred Spreafico

President of the International Commission for the Hydrology of the Rhine basin

Content

Introduction................................................................................................................... 1

1 Description of the Rhine River Basin......... 7

1.1 Overview ........ 7

1.2 Longitudinal and cross-sectional profiles....... 8

1.3 Human impact .......... 11

1.3.1 Hydraulic Works . 11

1.3.2 Reservoirs and hydropower......... 20

1.3.3 Water supply........ 24

1.3.4 Water quality ....... 26

1.4 Population..... 30

1.5 Land use ....... 30

1.6 Hydrometeorology.... 31

1.6.1 Climate and Meteorology  31

1.6.2 Hydrology 33

1.6.2.1 Runoff regime of the River Rhine .... 33

1.6.2.2 Influence of climate change on the runoff regime ... 36

1.7 Travel times .. 40

1.8 Hydrogeology ........... 42

1.9 Morphological landscape structure .. 43

1.10 Soils .. 44

2 Users........ 47

2.1 Stakeholders of small alpine catchments...... 47

2.1.1 Needs for protection (mainly natural hazards, soil loss). 47

2.1.2 Power and drinking water supply (reservoir sedimentation, abrasion

of turbines etc.).... 48

2.1.3 Construction (use of sediments, dredging) .......... 48

2.1.4 Other uses (habitat protection, recreation, environmental protection).... 48

2.2 Stakeholders of large lowland catchments ... 49

3 Problems related to sediment management .......... 51

3.1 Torrents and small Alpine watersheds ......... 51

3.2 Large river systems .. 52

3.2.1 Switzerland.......... 52

3.2.2 Germany .. 52

3.2.3 The Netherlands .. 54

3.3 Lakes  55

4 Necessary sediment observation .. 57

4.1 Switzerland... 57

4.1.1 Torrents ... 57

4.1.2 Rivers....... 58

4.2 The Netherlands ....... 60

4.2.1 Lakes ....... 61

4.3 Reservoir Sedimentation ...... 62

4.3.1 The Problem of Reservoir Sedimentation ........... 62

4.3.2 Consequences of reservoir sedimentation ........... 62

4.3.3 Sedimentation rate........... 63

4.3.4 Reservoir sedimentation by turbidity currents .... 64

4.3.5 Measures against reservoir sedimentation........... 64

4.3.5.1 Measures in the catchment area........ 65

4.3.5.2 Control of sedimentation within the reservoir.......... 65

4.3.5.3 Measures at the dam. 66

4.3.6 Todays’s needs for an approach for Reservoir planning. 67

4.3.7 Examples . 68

4.3.7.1 Obstacles: Submerged Dams in Lake Grimsel......... 68

4.3.7.2 Venting: Hydro Power Sarganserland .......... 70

4.3.7.3 Bypass-tunnel: Pfaffensprung.......... 71

4.3.7.4 Bypass-tunnel: Runcahez ..... 73

4.3.7.5 Sediment evacuation through power intake: Gübsensee...... 74

5 Available sediment data ... 77

5.1 Switzerland... 77

5.1.1 Historic background ........ 77

5.1.2 Sediment observations today....... 77

5.2 Germany ....... 80

5.2.1 Historical Background..... 80

5.2.2 River bed . 81

5.2.2.1 Geometry...... 81

5.2.2.2 Geology ........ 82

5.2.3 Sediment transport........... 84

5.2.3.1 Bed load........ 84

5.2.3.2 Suspended load......... 85

5.2.4 Grain size. 86

5.2.5 Petrographic composition 86

5.2.6 Data storing......... 87

5.3 The Netherlands ....... 89

5.3.1 Historical background ..... 89

5.3.2 Bed levels  90

5.3.3 Available data on sediment transport...... 90

5.3.4 Available data on grain size ........ 90

6 Monitoring equipments and methods ....... 93

6.1 Switzerland... 93

6.1.1 Bed load... 93

6.1.2 Suspended sediment ........ 93

6.1.3 Turbidity.. 94

6.1.4 Suspended solid load ....... 95

6.2 Germany ....... 96

6.2.1 Geometry of the river bed ........... 96

6.2.2 Geology and sedimentology of the river bed ...... 96

6.2.3 Bed load... 98

6.2.4 Suspended load.... 99

6.2.4.1 Permanent monitoring stations......... 99

6.2.4.2 Cross-section measurements .......... 100

6.3 The Netherlands ..... 101

6.3.1 Riverbed  101

6.3.2 Bed load. 101

6.3.3 Suspended load.. 103

7 Estimation Techniques ... 105

7.1 Switzerland. 105

7.1.1 Recommendation for the assessment of sediment yield in mountain streams .. 105

7.2 Germany ..... 109

7.2.1 Estimation of sediment loads in the German Rhine ...... 109

7.2.1.1 General remarks ..... 109

7.2.2 Bed load. 110

7.2.3 Suspended sand load ..... 110

7.2.4 Total suspended load and wash load ..... 111

7.2.5 Sediment balance and sediment budget. 111

7.2.6 Comparison of hydrologic, geometric, and sediment transport data..... 114

7.2.7 Morphological models ... 115

7.3 The Netherlands ..... 116

8 Legal, administrative and organizational aspects........... 119

8.1 Laws ........... 119

8.1.1 Switzerland........ 119

8.1.2 Germany  119

8.1.3 The Netherlands  120

8.2 Regulations . 120

8.2.1 Switzerland........ 120

8.2.2 Germany  121

8.3 Bilateral and multilateral agreements and treaties . 121

8.4 Cooperation in international River basin committees ........ 121

8.5 Organizations responsible for monitoring.. 122

8.5.1 Switzerland........ 122

8.5.2 Germany  122

8.5.3 The Netherlands  123

9 Selected recommendations concerning sediment management . 125

9.1 Flushing and emptying dammed waters ..... 125

9.2 Extraction of gravel, sand and other materials from water courses ........... 126

10 Rhine sediment quality and its management ...... 127

10.1 Sediment quality and assessment ... 127

10.2 Trends in Rhine sediment quality... 128

10.3 Contaminated sediment re-suspension risks........... 129

10.4 Sediment management ....... 130

10.5 Towards a management plan for contaminated sediments. 130

10.6 Preliminary findings SEDI group... 132

11 Examples of sediment studies .... 135

11.1 Switzerland. 135

11.1.1 River Alpine Rhine........ 135

11.1.2 Sediment balance in the Thur catchment area... 148

11.1.3 Reduction of erosion in the Emme river: Study „Emme 2050“  158

11.1.4 Assessment of sediment yield in the Weisse Lütschine, Canton of Bern ......... 180

11.2 Germany ..... 182

11.2.1 Bedload management at the Rhine River .......... 182

11.2.2 Selective transport and dispersion along the Upper Rhine –

results of a long term field test using a petrographic tracer ...... 188

11.2.3 Suspended sediment transport and sediment management in the

impounded section of the Upper Rhine. 195

11.3 The Netherlands ..... 203

11.3.1 Study German – Dutch border... 203

11.3.2 Morphological behaviour of bifurcations in the Dutch Rhine river system...... 204

11.3.3 Sediment budget of the Dutch Rhine River system...... 206

12 Literature  209

General Information about the International Commission for the Hydrology of the Rhine basin (CHR)....... 218

Publications of CHR... 219