The UK like many countries is prone to floods and to water shortages.
When we had a fully nationalised water industry in my youth we faced water rationing in summers with hosepipe bans and in some cases standpipe water. Since then we have had a large increase in population with regulated private monopolies not building additional reservoir capacity. They say they could not charge enough to pay for expansion. The Regulator never told them to expand capacity. Cutting UK CO 2 will have no impact on all the extra demand a fast growing population creates. The government needs to tell the Regulators to require an expansion of capacity.
Our flooding matters more now than in the past because governments and Councils have allowed and encouraged too much building on flood plains. The Planning regulators have failed to put in sufficient drainage capacity. The Environment Agency has failed to dredge rivers and expand capacity of ditches and culverts to get water away from buildings. Cutting migration numbers would help. A concerted programme of water diversion is essential Again decarbonising the UK will not stop floods on floodplains.
Sea defences need improving where spending can protect towns and cities. We should be working on a new London barrage further down the estuary.