The Joint Powers Agreement (a legal agreement) in section 3.1.2 page 11, clearly states that a Master Plan will be adopted by the parties.  The Master Plan includes the Arden Hills compressive plan for density. Shown below is the Ramsey County approval for a density of 1,460 residential units on TCAAP as required by the Joint Powers Agreement. 

The resolution was approved by the County Board.  A Ramsey County link (Ctrl + Click) to the press announcement can be found at:

Rice Creek Commons development plans pass major milestone | Ramsey County