On 28/02/2013 12:55, Richard Dixon wrote:
On Thursday, 28 February 2013 12:33:50 UTC, Anne Burgess wrote:

It seems to me that the people who should be paying for the
flood damage are the developers who build on flood plains,
haughs, watermeadows, inches, whatever you like to call them,
and the local authorities who give planning permission for such
developments.

Plenty of development seems to be on land that no local would dream of
buying a house on because they know it is prone to winter flooding.
Incomers stand no chance in this game and only find out that their nice
new home in a development on the edge of town is built on a dish of clay
that has flooded in wet winters ever since anyone can remember.

2012 has been particularly bad for excessive summer rain.

The other issue are the guidelines to which development is restricted. In these shifting times where (through anthropogenic means or otherwise) the climate is changing, if you don't allow construction, say, anywhere near the 50-year flood return period floodplain, then what exactly does this floodplain look like given that extreme rainfall seems to be one of the more likely bi-products of a broadly warming atmosphere.

The sensitivity of extremes (e.g. 50-year rainfall) in a changing climate can be much more volatile than numbers such as the average annual rainfall. Do we build outside the current floodplain or build outside the floodplain based on a future climate where flooding would be more likely?

You also have to do something about everybody concreting over their
garden so that when there is a sudden rain squall it doesn't all
immediately go down the drains as instant flash flood run off.

Countries that are used to monsoon rains tend to have large storm drains
for rainwater that are almost dry when not in use.

Even being on a hill is no defence. When the Newcastle storms occurred
last year my wife's works buildings took a direct hit when the metro
line flooded then its embankment breached and dumped many thousands of
gallons of mud down the hill and straight through their building.

I was at a research meeting recently that has been started by the Natural Environment Research Council that is trying to understand the uncertainties around such numbers. Very interesting it was, too!

I think the builders and planners should carry the can for some of the
more stupid new builds that are smack bang in line for flooding. It is
much harder where some flood management scheme has made a new problem
for another existing community up or down stream. Basically water will
find its own level and if there is enough of it you are in trouble.

Flood plains developed for a purpose - to hold large volumes of excess
river water during winter storms.

Help to ameliorate flooding should be offered to those in bad positions
to try and mitigate their flood risk, but some locations are untenable.
Maybe 3 strikes and you are out policy should apply to flooded houses...

I am no fan of the idea that everybody should have to contribute to a
fund so that people who live in locations with insane levels of risk can
get subsidised insurance. Market forces should operate on this.

--
Regards,
Martin Brown