Farringdon on the Thameslink route in Central London has a long history of flooding in the diveunder north of the station where it passes beneath the Circle Line. It also passes beneath the Fleet river, which is in a pipe, there, and is below river level. Way back in time London Transport long kept one of their service steam locomotives able to be fitted with a steam pump to pump floodwaters here up into the Fleet pipe, when this overwhelmed the locally installed pump. I believe this included the Metropolitan steam loco now in the LT museum, for its last duties. There has still been flooding there quite recently.