Your approach of making fines payable in equity might be an interesting way for the UK to renationalise the infamously underperforming private water monopolies. They incur fines all the time for things like pumping sewage into the waterways.

I don’t think they’d use this mechanism though, the whole point of water privatisation was to keep the much-needed infrastructure upgrades off the government’s books and nationalisation in general would subvert this goal. The glaring flaw in that plan is that the regional private monopolies didn’t do the needed upgrades either, and instead paid massive bonuses to their senior managers.