I have 3 desert tortoises that are about 3-4 yrs of age. They have hibernated before in past winters but in a insulated plastic tub that I would place in the shed. This year they made their first burrow and have not come out since its gotten cold. I have covered it up with tarp, however we live in fresno ca and it has been raining heavily. So much so that i'm afraid the water will saturate their burrow? Im not sure how deep they are. I can't feel any of them when I stick my hand down in the burrow. Should I be concerned? Or do you think the burrow is deep enough to keep them dry? I'm debating digging up the burrow? Any suggestions would be great!!! Thanks so much