By Milo Boyd Seven new parks reclaimed from a river will let everyday Brits enjoy a coffee and a sit down above the guts of one of the largest infrastructure projects in the country’s history. For the past eight years, hundreds of workers have been digging away beneath the River Thames, building 25km of tunnel that will radically cut the amount of sewage overflow which is dumped into the river each year when the Victorian drains overflow. Later this year the £4.3bn Tideway system will be tested for the first time, with the current overflow routes into the Capital’s main river diverted into the…