Wet mucky media or heavy wet soil is asking for trouble. Ginger needs a fair amount of water but is actually very sensitive to standing water and poor drainage. Yes it can tolerate heavy rains if it has drainage but then we worry about washing away valuable fertilizer. I like to saturate a well draining media and then wait until said media has become a little dry...not bone dry mind you.
As ginger grows in size it will extract more moisture from media and soil and you will have to increase the frequency of your irrigation operations.
Overly wet media will encourage disease. This especially true when combined with hot summer temps. As ginger rhizomes are fleshy and tender they are easy prey for any casual pathogens lurking as they like to do when conditions are right for them, wet and hot usually.
Ginger is fairly picky in its early stages when it comes to water. Over watering during presprouting and early transplanting is the main problem to watch out for - too much water causes ginger to sprout slower.
If you are growing in an arid climate, we recommend overhead irrigation. Unlike tomatoes, ginger likes wet leaves now and again.