I am, as yet, unable to find much information about this man-made waterfall. According to the plaque, it was built through the generosity of Marvin & Pauline Evans in cooperation with the City of Searcy and makes for a beautiful scene, or at least I imagine so when it was functional.
There are plenty of benches and picnic tables nearby under the shade of trees so it is a pleasant place to enjoy a meal and being outside.
You are looking for a contact lens case hidden in a difficult manner. No stone needs to be displaced nor any destructive behavior used in retrieving this cache. It is somewhere within the footprint of the fountain's rock work.
*** Congratulations GKMFalcon -+- FTF on 4/18/15 ***