I live in Sheffield in the UK and we have the largest amount of green space per capita out of any city in Europe and it is wonderful! In the late spring it often looks like they build the city on Endor there is that much foliage.

An innovative ‘green-to-grey’ project took place a few years back and has been such a success that they are now digging up the main high streets in the city centre to add more plants and better drainage there too.

https://sheffielder.net/2021/12/07/rewilding-our-urban-space-has-never-been-so-important/

https://www.examinerlive.co.uk/news/local-news/new-sheffield-fargate-overhaul-plan-26202840

According to local signage those large areas absorb the total of 10,000 bathtubs of water a year and stop it overwhelming the sewers and rivers. Sheffield is a very hilly inland city criss-crossed with rivers and heavy downpours make them swell.

https://www.thestar.co.uk/news/river-don-breaches-bank-in-sheffield-city-centre-3577289

This sort of thing is not unusual and happening on an annual basis.