Keep in mind this doesn't mean the pools close. It's just that the lifeguards leave earlier, and you must exit the pool when they leave. However, once they're gone you can return to the pool AT YOUR OWN RISK (as explained on the pool signage). We often bring our kids to the pool after we get back from fireworks, after the lifeguards have left. The waterslides are closed of course, but use of the pool is allowed, but again is at your own risk (as it always is at pools without lifeguards like most of the "quiet pools").