My reason for a 'Don't Know' response to the Havant Thicket Reservoir is due to not understanding what emergency plans are in place once it is filled should overflow / breach of reservoir banks occur.

As to sharing water with other regions I feel those companies should be forced to look at options and costs as you have within your region rather than taking benefit from neighbouring resource solutions. Appreciate they may be taking on some of the cost but specific regions will only hold enough water for specific populations, surely?