Flooding has been a feature of the blue orb's climate from the beginning. The key difference in then and now is the effect that human population growth has had, and continues to have, on the myriad things, large and small, which contribute to runoff volumes and rates. Generally, we seem to want to move rainfall faster, which results in higher flood stages. The causes of nth order problems are better understood today than in the recent past. The solutions, however, haven't gotten any easier; only more expensive, both economically and politically. It's enough to make a man cry out fer another pint.