I suggest contacting your city's Recreation Department. In our town, they are responsible for: city-run summer and day camps; after-school and sports programs; and community events. They also help run facilities management for local parks (hall rentals, etc.), and manage the community pool.
If your city doesn't have a Recreation Department, consider contacting local churches, particularly those with space to host a youth center or youth programs.
I hope these suggestions help, and that other JustAsk members will chime in with more!