There are several RV parks around Wichita.
There's one right in town called USI RV Park. I know nothing about it other than I've driven through it and had a friend stay there for several months.
There's another one west of town in Goddard called All Seasons RV Park. I know nothing about it.
There's Cheney State Park 20 miles west of Wichita if you prefer a more scenic and quite space. We spend a lot of time there in our 5th wheel throughout the year. There is no sewer available.
There's another one about 35 miles NW of Wichita called the Hitchin Post RV Park. I've stayed here when we had no electricity at the house. It has sewer and a laundry room but no shade at all.
Here's a link to RV Park Reviews where you can review all RV parks in or near Wichita.
http://www.rvparkreviews.com/regions/kansas/wichita