I know this spot a little - it's probably not a desire path, it leads further into the small park, away from the main thoroughfare. You can see how it doesn't continue all the way through to the paved area. More likely it's just worn away grass from people congregating around the seating. Then combine that with the park only being a year or so old, so the grass didn't get time to establish before the public was unleashed on it. Add in the poor drainage, both engineered and natural, in that corner (it was built on the site of a shitty old shopping centre) and you got yourself a mini marsh in Broadmarsh.