Unfortunately, the winter can bring storms and undesirable weather, which can sometimes result in flooding and excess standing water. It can be so disheartening to see your plot under water and there is little that can be done until the water has naturally subsided unless it is minor and there are some steps you can take to help get things back on track.
If your plot is prone to flooding, there are also some precautionary measures you can make to help prevent flood damage.
Standing water can cause damage to the plants' root systems; causing rotting as well as contamination to the soil. The water will also strip away valuable nutrients from the soil.
If the ground is workable, you can make holes in the ground with a fork to help with drainage and air get to the soil to help it dry out. Acidic soil will need lime adding to help it and you can also plant strategically to help the soil.
There are crops that will withstand wetter conditions and poorer drainage; plants that like lots of water too. They will help to replace nutrients in the soil. Some examples are asparagus, rhubarb, mint, some varieties of spinach and pear trees. Strawberries too.
As they say, prevention is better than cure and so there are ways in which you can help protect your plot from future flooding too.
One way would be to use raised beds for your planting or even mounding up soil and using no-dig methods; obviously taking your crops higher than ground level to prevent water damage.
You can also look at how you can work on making ditches/trenches and barriers; particularly if your plot is on a slope and the water tends to gather in a certain place.You can also consider various drainage systems from urban to natural ponds, which adds the benefit of attracting wildlife.
It may take time for your plot to recover fully and your soil will need a lot of 'TLC'. Once it is workable, you can aereate it, keep adding organic matter and let the sun do it's thing too.