Chouteau Park is just largely a graded empty lot right now, awaiting funds to become a fully realized park space. The design was done by H3 studios in 2009 who seem to be the firm that does all the park designs/master plans (Fox Park, Carondelet, etc).
The full plan can be found here. An update was provided by Washington University Medical Center Redevelopment Corp. back in November, 2011...