Put your towns and cities on hills.

Towns grew next to roads and rivers. These went along valleys. This meant towns often grew over good farmland. New housing estates are often put on flood plains, as if the name 'flood plain' didn't contain obvious advice.

On the hills, you get good views and clean air. Not all the roads would go up and down. The hills of San Fransisco ought to be a good example, but I remember seeing a subway completely full of water after freak rains up on the hills because the drains had been blocked with waste paper.

There will still be ports and airports which cannot easily move to the hills. You could look at what they do in Holland. Roads and railways raised on dykes. That would not make the roads safe from flash floods, but it ought to give you more of a change to get to higher ground on good time.

Put your towns and cities on hills.

Towns grew next to roads and rivers. These went along valleys. This meant towns often grew over good farmland. New housing estates are often put on flood plains, as if the name 'flood plain' didn't contain obvious advice.

On the hills, you get good views and clean air. Not all the roads would go up and down. The hills of San Fransisco ought to be a good example, but I remember seeing a subway completely full of water after freak rains up on the hills because the drains had been blocked with waste paper.

There will still be ports and airports which cannot easily move to the hills. You could look at what they do in Holland. Roads and railways raised on dykes. That would not make the roads safe from flash floods, but it ought to give you more of a chance to get to higher ground on good time.