Jerry - a gravid female turtle is an escape that WILL happen. They won't lay their eggs in soft ground and they won't lay them at water level. They are acting on instinct and their instincts tell them that they MUST find ground that is above at least the 50 or 100 year flood plain so that the eggs, which are permeable, will not drown before they are ready to hatch. Your female will wander around, generally heading uphill until she finds the perfect spot and then will dig her hole. The hole will be big enough for however many eggs she's carrying (5 to 8 if it's her first lay, up to 16 if she's older and has done this a few times) but the opening to the hole will be just big enough for the egg to drop thru it. She will use her own urine to make the ground soft enough to dig. Then she'll close that hole up and even if you watched her dig it and cover it, you may not be able to find it when she's done. I always dug up the eggs and incubated them in a safe place because there are so many predators that will destroy the nest or eat the babies as they hatch. It takes about 70 days for RES eggs to mature and then they will usually hatch during or immediately after a rainstorm - presumably because the ground is then soft enough for the babies to dig out.
