The first step in saving your waterlogged lawn is to avoid walking on it as much as possible until the water has drained away. Walking on your lawn will only exacerbate the problem as it will further compact the lawn, and is likely to pull up the grass from the soil turning your lawn into mud. If you do need to walk on your lawn, try and spread your weight as much as possible by walking on wooden boards.
If water has pooled on your lawn and doesn’t seem to be draining away after a few days, then try and gently brush the excess water off the lawn into either a run off area of the garden, or down a drain. Be careful not to pull the grass out of the lawn when doing this. Use a soft bristle brush for this so you are as gentle as possible on the lawn.
When the majority of the water has drained away, spike the lawn with a garden fork. The deeper you spike the lawn the better, as it will open up the soil and allow the air to circulate, promoting healthy grass growth. Deeply spiking the lawn will also help the water, penetrate deeper into the soil – therefore enabling it to be absorbed into areas that it may not have been able to reach previously due to compaction.
The best tool to use for aerating your lawn is a hollow tine aerator, which pulls up plugs of soil from the lawn. Leave these soil plugs on your lawn and gently break them up with a brush to enable them to breakdown back into the lawn.
Regular aeration of your lawn over the spring and summer months is essential to limit the risk of lawn compaction which often leads to waterlogging of your lawn.
If your lawn remains wet for long periods then it may be necessary to take additional corrective action. One way is to add a thin layer of top soil or garden specific sharp sand to the affected areas of your lawn - this will help draw out the moisture in the soil helping it to recover more quickly.
If your lawn regularly suffers from waterlogging then it may be worth taking a couple of easy preventative measures. If your lawn is uneven and has areas that commonly become waterlogged why not try and level them out. This will stop water from collecting in a single area of the lawn.
You could also try and over-seed your lawn during the spring/summer. Over-seeding is a process where you lay additional grass seed to create a thicker lawn. Not only does this help prevent moss from growing and create a thicker, healthier looking lawn, but it also creates a more complex grass root network, enabling it to absorb more water. Remember to allow the new grass seed to grow at least 2-3 inches in height before walking on it. Before moving for the first time check your lawn mower has a sharp cutting blade before gently cutting no more than 2-% off the height of the new grass. Any more than this will harm the grass and the chances of it growing.