Flood Risk Management

1 Flooding and flood estimation 1
George Fleming and Lindsay Frost
1.1 Historic development of flood plains, 1
1.2 Effect of historic towns on flood risk management, 3
1.3 Early flood estimation, 6
1.3.1 Early 20th century developments, 8
1.3.2 The advent of statistical methods, 9
1.4 The Flood Studies Report, 9
1.5 The Flood Estimation Handbook, 14
1.6 Use of computer models, 20
1.7 Human dimension, 22
2 Flood risk 27
Stephen Huntingdon and Kenneth MacDougall
2.1 Assessing risk, 27
2.1.1 Existing approaches, 27
2.1.2 Dynamic conditions and uncertainty,28
2.1.3 Understanding real risk, 28
2.1.4 Wider benefits of risk approach, 28
2.2 Defining risk, 30
2.3 Holistic approach to flood risk management, 33
2.4 Communicating risk, 36
2.4.1 Flood awareness, 36
2.4.2 Locations at risk, 39
2.4.3 Expressing the risk, 39
2.5 Best practice for UK flood risk management, 41
2.5.1 Need in the decision-making process, 41
2.5.2 Consistency, 43
2.5.3 Cost-benefit evaluation, 46
2.5.4 Standards of defence, 48
2.5.5 Standards of preparedness and response, 48
3 Catchment and river basin management 51
Lindsay Frost and Donald Knight
3.1 Strategic river basin management, 51
3.1.1 Need for a strategic approach, 51
3.1.2 Catchment flood management planning in
England and Wales, 51
3.1.3 Scope of catchment flood management plans,
57
3.1.4 Application within the catchment, 59
3.1.5 Future support for catchment flood
Management plans, 65
3.2 Catchment modelling, 75
3.2.1 Role of catchment modelling, 75
3.2.2 Limitations to modelling, 78
3.2.3 Hydrological modelling, 78
3.2.4 Hydraulic modelling, 81
3.2.5 Future modelling issues, 87
4 Urban drainage 91
Charlie Rickard
4.1 Urban environment and flood risk, 91
4.1.1 Background, 91
4.1.2 Sewer flooding, 93
4.1.3 Urban channels, 94
4.2 Analysis of the problem, 97
4.3 Development of solutions, 98
4.3.1 Urban watercourses, 98
8
4.3.2 Urban sewer systems, 105
4.3.3 Sustainable urban drainage systems, 107
4.3.4 Sewer and drainage system design and
Modelling, 109
4.3.5 Scope for flood alleviation measures in
Historic towns, 111
4.3.6 Development in flood risk areas, 114
5 Engineered solutions 115
Charlie Richard
5.1 Role of engineered solution, 115
5.2 Sustainability, 116
5.3 Getting the balance right, 118
5.4 Availability options, 121
5.4.1 Storage options, 122
5.4.2 Conveyance options, 126
5.4.3 Other options, 131
5.5 Design approaches, 132
5.5.1 Risk and uncertainty, 132
5.5.2 Examination of options, 134
5.5.3 Catchment flood management plans, 135
5.5.4 Design standards, 136
5.5.5 Freeboard, 139
5.6 Policy for existing defended areas in our towns and
Cities, 141
5.7 Operation and maintenance, 142
5.7.1 Flood defence assets, 142
5.7.2 Flood defence asset surveys, 143
5.7.3 Operation of flood defences, 145
5.7.4 Maintenance of flood defences, 146
5.8 Flood defence expenditure, 147
5.9 Research and development, 147
6 Flood management tools 151
Stephen Huntingdon, Donald Knight and Kenneth
MacDougall
6.1 Existing systems, 151
6.2 Flood frequency estimation, 151
6.3 Flood forecasting, 154
6.4 Flood risk mapping, 155
6.4.1 Background, 155
6.4.2 Recent developments, 157
6.4.3 Future development, 157
6.5 Flow forecasting and real time control, 158
6.6 Availability of data, 163
6.7 Future tools and procedures/systems for flood
Management, 164
6.8 Research and development requirements, 165
6.9 Emergency planning, 165
7 Impact of climate change and catchment dynamics 169
Frank Law
7.1 Assessment of studies, 169
7.2 The impact of climate change on flood flows
and water levels, 172
7.3 Future needs, 173
7.4 Catchment dynamics, 174
7.5 Technical response to change, 175
8 Skills 181
George Fleming
8.1 Needs, 181
8.2 Training, 183
9 International 185
George Fleming, Stephen Huntingdon, Donald Knight
and Frank Law
9.1 France, 186
9.2 Netherlands, 187
9.3 Italy, 188
9.4 United States, 191
9.5 Japan, 193
9.6 Summary, 197
10 Supply and delivery 199
Lindsay Frost
10.1 Current roles and responsibilities, 199
10.1.1 England and Wales, 199
10.1.2 Scotland, 203
10.2 Insurance, 204
10.2.1 Introduction, 204
10.2.2 The industry viewpoints, 205
10.2.3 The consumer viewpoint, 207
10.3 Key issues in supply and delivery of flood risk
Management, 208
10.3.1 Do we need to review roles and
responsibilities for flood risk
management?, 208
10.3.2 How can we improve public awareness
of roles and responsibilities?, 209
10.3.3 Are sufficient resources available to
deliver a national strategy for flood risk
management?, 210
11 The future for flood risk management 211
11.1 Present conditions, 211
11.2 Raising flood awareness, 212
11.3 Promoting the human dimension, 213
11.4 Planning for floods, 214
11.5 Designing for floods, 215
11.6 Asset management, 216
11.7 Research, 217
11.8 Model development, 223
11.9 Skills shortage, 223
11.10 Availability of data, 224
11.11 Resourcing, 226
11.12 Responsibility for flooding, 226
11.13 Legislation, 227
11.14 Concluding summary, 227
References 229
Index 241