Mahoney Aquatic Center (in Eugene T. Mahoney State Park) is still open! We visited over the weekend.
Cost: $10 adult/$8 child
Hours: 12:00 noon-5:00 PM
Days: Open on Saturdays and Sundays til Labor Day
What does Mahoney Water Park have? They have multiple slides, a diving well, a pool, a splash pad, a toddler/preschool swimming area and a wave pool (my personal favorite).
We spent the entire afternoon there and it was delightful. It was crowded but it is one of the only public pools that is open in our area and it is really hot out.