The restrictions on the use of hosepipes is officially known as a Temporary Use Ban and includes: 'Drawing water, using a hosepipe, for domestic recreational use.'
We consulted with Thames Water and they have advised us as follows:
"The definition of domestic recreation use is:
a) recreational use in connection with a domestic swimming or paddling pool or on land that is used or enjoyed in connection with a building, or part of a building, used principally as a dwelling, other than for the purposes of a business;
b) recreational use on land that is used or enjoyed in connection with a building …used principally as a dwelling….
Therefore it will be possible to fill a motorhome or caravan water tank using a hose during the Temporary Use Ban. "