10,000 acres (+/-) has been set aside as wetlands . . . . . .
From Yahoo! Answers . . . .
Walt Disney World Resorts employs over 58,000 people and is over 30,500 acres (about 47 square miles). Currently, only 7,000 acres are developed though. 8,200 acres of the land owned by Walt Disney World will never be developed upon because it is a designated wildlife preserve.