It's a burst water main. Water comes up on the right, flows across the road and goes into the drain on the left. It's been doing it for months. I remember it froze over in winter, it's been leaking for that long (indeed, it could have been the cold weather that burst the pipe). 40 years ago, a gang of men would have showed up, dug a hole, repaired the pipe and that would have been that. Today, though, the fact that a gang of men costs more to employ than the lost water is worth means the leak won't get fixed until the road surface is damaged.
Maybe they're waiting until everyone is on holiday so there will be minimal disruption to the flow of traffic out of the station? That's the kind of plausible excuse they might come up with, yes...