re: Are these sod web worm webs?

As others have said the abundance of small white moths flying when you walk through or mow the yard will be the best indicator of sod webworms.

The brown patches won't be far behind. They wrecked most of my backyard in a matter of weeks a few years ago.

I used liquid insecticide I got from Lowe's, Spectracide Triazicide with success.

ETA: I suspect there is some truth to the 2016 flood. We came within a few inches of water in the house and never had trouble with these webworms for the 14 years we lived here previously.