Past failures and design lessons

• 2.1.

  Introduction

• 2.2.

  The UK 2007 summer floods

• 2.3.

  Lessons from the Ulley Reservoir

• 2.4.

  August 2008 floods in Northern Ireland

• 2.5.

  Hurricane Katrina

• 2.6.

  Conclusion

• References

• Further reading

This chapter considers a number of different flood events that have caused widespread impacts, in order to draw some lessons from them for design engineers. In each example the causes and the impacts of the event are outlined. The summer floods of 2007 in the UK are considered, with a detailed examination of the risks associated with impoundments from the Ulley Reservoir. This event shows the risks of surface water flooding, the vulnerability of infrastructure, and likelihood of flood risk increasing with climate change. The significant flood event that occurred in August 2008 in Northern Ireland is used to show the limitations to the design capacity of a culvert system, and the risk of overtopping of flood defence structures. Finally, the catastrophic flooding caused by Hurricane Katrina shows that design standards can be misleading, that maintenance must be joined up if flood defence systems are to work, and that predictable events, such as hurricanes, demonstrate the need for early warning systems and forecasting as an active part of flood risk management.