I think the pertinent point is not about how much (it's reported as 5mm). The point is that when you have so much moisture below the crusty bit on top (which is giving you the impression of good ground) all it takes is a small amount of water to create difficult conditions and often false ground.
I think the pertinent point is not about how much (it's reported as 5mm). The point is that when you have so much moisture below the crusty bit on top (which is giving you the impression of good ground) all it takes is a small amount of water to crea