Shanghai Disneyland will not be alone.
A new water theme park is under construction in Shanghai's Pudong area, 25 minutes from Shanghai Disney Resort. It is 190,000 square meters with a planned investment of 3B Yuan (482.74M USD). It is scheduled to open on 2017.
Source:The park, located near Dishui Lake, Shanghai's biggest artificial lake, will feature various marine animal species and is expected to receive over 6 million visitors per year after completion
http://news.xinhuanet.com/english/2015-03/30/c_134109840.htm