But a longer term strategy must involve comprehensive catchment management and better investment decisions. Our results show that only about half what the public really loses in floods is counted as benefits: none of the important 'intangibles', such as evacuation impacts and adverse health effects, is yet included.
Fundamental also is a revision downwards of the 6 per cent Treasury Discount Rate, which means that investment in flood defences is made only when the benefits in terms of flood damage avoided exceed the costs by 6 per cent per annum, approximately double the historic rate of return on private sector investment.
The Government's expectation of a return from its investment in keeping people dry of double that from private capital, and triple the rate of inflation, is a major reason why we are now seeing the extent of flood damage being suffered today.
E. C. PENNING-ROWSELL
Flood Hazard Research Centre