Not OP, I couldn't find a paper. Just this site that makes the same claim almost word for word, and cites a youtube video of a lecture at Stanford. I didn't watch the video, but this seems best described as a "plausible" explanation rather than a proven fact.
If you get to the Pearly Gates as a fat mole rat, point out to St Peter that with climate change and rising ocean levels, Heaven may need your attributes soon.
This says there are fat naked mole rats, but it says their role is to connect to other naked mole rats communities by digging when the ground is soft from rain. That's quite different from the claim that their role is to block the tunnels to stop them flooding.