Site drainage is a must; best done b4 laying or planting a lawn.
But do not give up just yet, as it is never too late to fix the problem.
The water must be allowed to drain away to a safe place.
This can be achieved by firstly locating an existing stormwater drain or other existing way of moving water from your property.
Next, provide a way for the problem water to move to the existing drain. This can be done via an undergroung “ag drain” or surface drain in the shape of a dish. The shape of the dish drain will depend on the slope of the land and how much water you expect.
Goodluck ,Reg.