Still, take a look at google maps pic. This is not a huge lake. Spread that much water out over 40-50 miles of downstream acreage and it might or might not have a noticeable impact.
The problem is that a Levee near Kentland (??) has burst, and water from a dam break would flow through that levee.
You are correct it is not a huge lake. The population below the lake and park is scattered and rural. I used to go to the park and lake when I worked in the McComb area many years ago.
The Tangi River is basically an stream but with all of this rain who knows what it looks like now.