In article ,
Stephen Wolstenholme wrote:

When it's not Winter most rainwater that falls evaporates before it
gets into reservoirs even when there isn't much Sun.

That is an oversimplification, bordering on a falsehood. It is
true for the driest parts of the country, but assuredly not for
the country as a whole. In the wetter parts, evaporation never
exceeds precipitation, on average.

The average evaporation in the UK is about 11", almost all in
summer, and the average rainfall varies from 19" to 40+" in the
populated areas (and a LOT more in a few places).

Most of the rainfall finishes up in the sea rather than reservoirs.

Fine. That is an entirely separate point and, if it were not,
would contradict what you said at first.

If you are comparing the water that reaches reservoirs (necessarily
only from their catchment area) with the evaporation over the whole
country, your statement is close to trolling. In the catchment area
of reservoirs, very little rainfall reaches the sea before it is
used in some way.

If you had said groundwater rather than reservoirs, it would have
been closer to the truth but, even there, I believe that claim is
more polemic than fact except in the drier parts of the country.
If you can provide actual figures, I should be interested - I did
not find any when I looked.


Regards,
Nick Maclaren.