This is providing free bags and sand for people to protect their homes. Since there's no profit involved, I'd expect the inmates volunteered rather then being forced. There's minimal upside to forcing them if nobody makes a profit.
They provided bags and sand but residents had to bring shovels and fill their own bags. You can see in the picture and read in the article, the inmates are helping residents who need it. Many inmates have jobs. Spending a day outside, interacting with people, and helping the community in a difficult time seems like a pretty good one.
I'm not sure what you mean. The article clearly says that residents brought shovels and inmates helped those who needed it. When i worked with inmates they all wanted the golf course jobs because they got to be outside interacting with people.