Spillways on River Levees

Foreword
Introduction

1. Background, definitions, various configurations
Typology of flood protection levees on rivers
Protected areas and flood expansion areas
Typology of spillways on levees

2. The historical background of spillways in France
1584 to 1891: The first spillway constructions on the Loire and Vidourle Rivers
20th century: Several scattered constructions and major development of the Rhône River
21st century: A relative acceleration in construction

3. The hydraulic design of spillways
The spillway’s impact on the flooded river’s waterline
Impact of the spillway on the waterline in the protected area
The spillway’s flow law
Spillway location
Protection, safety, and danger floods
The principle of flood attenuation or flood hydrograph flattening
General hydraulic design principles
The required modelling

4. Spillways and river geomorphology
Overview of sediment transport
Overview of morphological changes in watercourses
Morphological changes in leveed watercourses
The spillway’s influence on sediment transport (riverbed)
Sedimentation behind spillways
The influence of bed change on spillway performance
Torrents

5. Civil engineering design for levee spillways
Safety criteria for levee spillways
Principles of fuse plugs or movable devices
The plan shape of the levee spillway
Types of straight weirs and constituent materials
Fuse plugs or movable devices
Continuous maintenance tracks
Overflow erosion on earthen levees

6. Emergency management of the levee system
The benefits and limitations of spillways in emergency management
The types of emergencies to manage
Considerations before drafting an Emergency Management Plan
Emergency management and levee managers
Local Emergency Action Plan (LEAP)
Special Emergency Management Plan for Flooding

7. Economic aspects

8. Summary and Conclusion
The benefits and limits of a spillway in a protected area
Spillway features
Is a spillway always required in a protected area?
Concluding remarks

Appendix 1. Spillway types on river levees, according to their hydraulic function and their purpose in flood management

Appendix 2. A history of spillways on the Loire River

Appendix 3. Overflow levees and spillways in the CNR’s Rhône River development

General principles
Example 1: The Chautagne plain and Lac du Bourget
Example 2: The Printegarde plain in Livron-sur-Drôme

Glossary
Reference List