Some new documents filed with Buena Park have revealed a planned expansion for the Soak City, located next to Knott's Berry Farm, for spring 2017. The documents reference a $5 million expansion that will see part of a current parking lot taken over by new attractions.
Above is the area of work, in the lower right, as it is now. Pretty much a parking lot and the Pacific Spin tornado water slide. Here is how it actually looks, courtesy of Google:
From the plans it appears as though the park will actually retire Pacific Spin, probably sending it to another water park in the chain that does not have a tornado slide (though there aren't many). A new fusion slide looks to use the Pacific Spin tower, and beyond it will be a new six slide tower. There will also be new cabanas and areas to relax.
Here is the fully built out area, showing the expansion to the park. It will take up a lot of parking lot, but the theme park has purchased two lots from the city that will be redeveloped as parking spaces to make up for the loss.
This image is included in the filings of the new Constrictor Python water slide that would replace Pacific Spin. The ride uses an extra wide slide design that incorporates tight enclosed turns with sections that are meant to have the raft bounce up and down the side, almost like the tornado slide does. The OC Register has a story on the expansion which does not mention this addition at all, which is curious, but I don't see why it would be included on the plans if it wasn't being built. You never know though, perhaps the finished expansion will include only some or all of these pieces.
The major slide addition is a slightly modified version of the tower that has been installed at other Cedar Fair parks, at Worlds of Fun, Dorney Park, Kings Dominion and this year Kings Island and Carowinds. Those towers all have a constrictor (they're all made by Whitewater West) slide as part of the mix, but the Soak City version will increase the free-fall drops by one to offer four, with two traditional tube slides off the back like the others. The change makes sense if the large constrictor fusion slide does in fact replace Pacific Spin.
Here is another view of the new slide tower, which will be set back from the park will the new cabanas and other amenities in front of it. The bright colors will surely attract plenty of guests to the park to check out the addition. The article linked above does mention that Soak City hasn't been updated since 2006 when Pacific Spin was added, but attendance numbers have steadily increased nonetheless. Expect an official announcement from the park with plenty more details and the final list of additions later this summer.