Then you are wrong. Where did I mention recreational use? The distinction is between domestic and industrial use. Heritage railways and rail tour companies are businesses and would therefore count for industrial use. If it got really bad, however , they could ban non essential industrial use.
I didn't say you said anything about recreational use, I just said that if there is only a choice between domestic and industrial use, recreational use should not count as industrial use.
I would bet money that the gross turnover each year from sales of products and services related to gardening is significantly higher than the gross turnover from all railtours (let alone restricting it to just steam railtours), so water for gardening would be at least as beneficial to England than water for railtours. If there is not enough water for gardening, then there is not enough for railtours.
There is also another parallel which suggests gardening should be at least as high a priority for water allocation as railtours. If you're short of water for your garden, you can switch to more drought resistant plants which require less water. Likewise, a railtour can switch to using a locomotive which requires less water. Viable compromises exist for both of these leisure-based business sectors during water shortages.
I agree that a distinction needs to be made between commercial activities that produce a significant national benefit and those which do not. Just because somebody makes a profit from it does not make it an industry.
Why would you hope that?
These railtours are run as businesses just like any other.
In the same way that golf clubs will be able to pour water onto the ground to keep THEIR businesses going.
Why would I hope that? Because more people would draw satisfaction or their daily bread from gardening than they would from railtours.
Golf clubs should be using recycled water or rainwater collected and stored on-site for maintaining the courses. If they are not, then they should be relegated to the same level as maintenance of gardens.
Perhaps in the light of this recent shortage of water leading to restrictions, the UK government could introduce a rebate or tax credit system for the purchase of rainwater tanks, grey water recycling systems and other water-saving devices. Planning laws could be amended to make inclusion of rainwater collection and storage compulsory for all new buildings, which could help keep the load on ageing water infrastructure down as well as making supplies go further.