Building a reservoir involves flooding the land. Due to UK topography suitable sites are often those where people historically built houses - sheltered and low-lying with access to a nearby water course or natural underground aquifer.
Look at the history of some of our notable reservoirs - residents were evicted, houses demolished, communities and whole villages destroyed.
In the main, those reservoirs were built to service the needs of the towns and cities, not the small villages in whose path they stood. Whenever a new reservoir is proposed there is usually local objection because construction is never without cost to the local communities. Why should rural residents be expected to make sacrifices so urban ones can gleefully flout hosepipe bans?
If each town and city was expected to manage its own water resources, including construction and maintenance of reservoirs, then perhaps there might be better awareness of what exactly a water shortage looks like.
London is already severely water depleted. Ten million people in a densely packed urban environment which consumes most of its water in domestic settings rather than agricultural, illustrates how unsustainable current water use is in relation to current water resources.
In the 1980s the population of London was approximately 6.7 million, in 2025 it’s roughly 9.8 million. That’s an increase of 42%. If we used the same amount of water per capita back then as we do now (140 litres per day) that's an increase of 434 million litres per day, to the rather astonishing sum of 1.3 billion litres of water each day!
London is clearly not self-sufficient in water, nor would it be if all the leaks were fixed overnight.
Obviously London needs a new reservoir or two. Question is, where should it be built? Islington? Wandsworth? Hampstead is no good because it’s on a hill. How about flooding Camden Town instead? Nice and flat there plus there are a few underground rivers such as the Fleet which are nearby and could be diverted to supply it.
I’m assuming those shouting ‘just build new reservoirs’ would be in favour - or are they expecting the inconvenience to be suffered by other people, anyone basically who isn’t them.