No. You can add the Water Park and Sports option to your 3/4 day ticket or, purchase a water park ticket separately.
I just ran the cost on the ticket calculator and it's about $3/person less to add the Water Park and Sports option to your 3/4 day ticket which would give you 3/4 days at the water parks plus 3/4 park days as opposed to purchasing the water park ticket separately for a single day. Adding the WP&S option is the better option for sure.