Judging by the wiggles and squiggles in the lines--I suspect the ground is rather uneven. Try to level it with topdressing with sand. It should help with drainage also.
Can you mow with a cup of coffee in your hand? If no, then it could be a lot more level. Do you have a good crown for drainage? I have heard about an 18 inch crown down the center is best. You need some laser leveling. Particularly when you decide to do a complete redrainage and renovation. (Using soil that drains better).