Drop Waterworks immediately from your plans. It will probably be flooded by the time of your visit and, really, it will be just as painful to play when it's above water.
When you say "walnut creek", do you mean Walnut Ridge or Big Creek? or both? Of those, Big Creek will be the one that is open to play as Walnut Ridge will be closed until probably May. Grandview is also a solid choice for fun but lacks in difficulty.
Also, be aware that we have quite a bit of snow on the ground which is currently thawing at a good pace, but things in Iowa do change quite quickly so we might have it all gone, leaving a muddy mess on the courses or we could have 6 more inches on the ground.