Just make sure you checked the weather on the date that you're planning to go, coz when it rains, they send everybody out and close the water park. They do give rainchecks.
Yes, they have have umbrellas and other areas that can be reserved and they are very affordable. However they do get booked up quickly, so make sure to reserve ahead of time and they only open during the summer months. They also allow coolers and certain food items in the park so it's a nice spot for a birthday party.
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