Yes water - at that link with all the photos, there is a body of water and someone replied that yes, it is Lake Elsinore. Couldn’t imagine what else it could be so I asked...I knew there are man made lakes on the western portion but didn’t think any fire had gone down there...
here’s a flyover for you, showing perspective of Lake Elsinore.
https://www.youtube.com/watch?v=slBRqhGjKkY