garden flooded uk advice please?

[Mitch]

garden has become increasingly waterlogged over the last 7 years the house is roughly 50 years old so this is reasonably a recent problem at the moment my garden is unusable as it is a mud bath my question is what professional type do i need to contact to find out the cause, is it the water board to see if it is a leaking undergrond pipe, a landscaper, or a surveyor, or the council though i own the house would they be able to give me a plan as to if there are in fact any pipes underground in the garden i am a total loss as to which way to turn and it is causing me a lot of stress i am even begining to feel that maybe the property nearby has a soakway draining into my property and i am fearful my foundations may be at risk because of the excess water,, i am at my wits end and any feed back and advice would be most appreciated i have lived at this house for 30 years, thankyou in anticipation