Swimming season was off to a splash this weekend at Jefferson Pool. Parks and Recreation staff say the pool has been averaging about 70 users per day since it opened June 13, with at least one day that saw 170 users. The pool is primarily for kids 10 and under, but older siblings can swim with their brothers or sisters, recreation supervisor Andy Coleman said. Cost to use the pool is $1 per child and free for parents to watch over the kids, except for Saturdays. For several years now an anonymous donor has paid so children can swim free on Saturdays. Open swim hours at the pool are 12:30-4:30 p.m., seven days a week, including July 4. Jefferson Pool is behind the Senior Center at 720 Sprague Ave. The pool will remain open until that last Sunday before school starts.