Microsoft is building even bigger in Iowa. The company today unveiled plans to invest a whopping $1.1 billion in a new data center campus in West Des Moines, where it already operates a large server farm. The project will be one of the largest in the history of the data center industry, with plans calling for 1.2 million square feet of facilities across a 154-acre property. The announcement ends the suspense about the identity of the mystery company behind Project Alluvion.