The annual report for the Rock River Rapids season was presented at the Derby Recreation Commission board meeting on Nov. 11. DRC Aquatics Director Donita Grinde-Houtman highlighted both challenges and successes from the 2025 season, following up on one of the aquatic park’s most successful seasons in 2024.
The biggest shift from last season was an adjustment in the state’s Sunflower Summer program. By being part of the program, Rock River Rapids had nearly 114,120 attendees in 2024 — an attendance record — and finished with $366,242 in revenue over expenditures. With the 2025 update from the Sunflower Summer Program, Rock River Rapids was not eligible to participate due to updates on theme and aquatic parks in the program.
Attendance numbers for the 2025 closely mirrored those of the 2023 summer, including the total revenue. Rock River Rapids earned $776,660 in revenue in 2025, which was slightly more than the 2023 season, which had $757,753. Rising costs in equipment, facility supplies and contracted services added to a revenue over expenditures totaling $52,282 for the 2025 season.
“Looking at our numbers, it’s clear how much Sunflower Summer inflated attendance last year,” Grinde-Houtman said. “This year gave us a more realistic apples-to-apples comparison with 2023.”
Rock River Rapids’ attendance for regular afternoon sessions aligned closely with pre-Sunflower Summer patterns. The attendance totaled 82,069 in 2025, which was slightly more than the 77,936 in 2023. Weather was a significant factor in 2025, with 44.75 total weather closing hours. That was a significant jump in weather closing hours, as the 2024 season had just 15.5. The 2023 season had just 27.5 weather closing hours.
Other areas — such as season pass sales, swim team revenue and gift shop purchases — saw noticeable declines. An unexpected cold snap forced the facility to delay opening for the first four days of the season, including a delay to the season-opening day — something Grinde-Houtman said had never happened in the park’s history.
“We started off the season with some delays with weather and had rain throughout the summer,” Grinde-Houtman said. “It was the first time for me to see that many cold weather days, especially at the start of the summer.”
Despite those dips, the facility also experienced several areas of growth. Otter party rentals increased by 16 bookings, adding more than $2,000 to the season’s revenue. Fitness programming also continues to climb, with a 62% increase in participation since 2016. A new “River Walk and Talk” self-led class offered guests a flexible workout option, and an advanced river running class expanded options for more rigorous training.
A major shift also came from the local swim community. For the first time in more than a decade, Rock River Rapids hosted only one swim team — the newly merged Derby Dolphins and South Kansas Storm. The consolidation resulted in just two home meets, and the facility did not host its usual June invitational or the July league meet.
One bright spot for families this summer was the arrival of a new treehouse-style slide in the shallow pool, replacing the outdated bug slide. Installation proved more complicated than expected — the slide’s footprint didn’t perfectly match the original specifications — but collaboration between DRC staff and city crews ensured a safe and well-designed final layout. Additional safety padding and a redesigned landing zone have already earned high praise from guests.
The report also included details on rising equipment costs, delays in delivery due to tariffs on replacement tubes, storm-damaged lifeguard stand repairs, and upcoming expenses such as recoating a small floatable and replacing a larger one. Despite the challenges of the 2025 season, it was a positive year for the waterpark, which celebrated its 21st season.
“We definitely had a successful summer, even though it started out a little bit rainy,” Grinde-Houtman said. “We appreciate everything everyone does to help us keep running smoothly.”
Cody Friesen is the sports editor for the Derby Informer. Contact him with sports tips at sports@derbyinformer.com, and follow @Derby_Sports on Twitter for the latest updates.