Bring vegetables and water to boil in saucepan on high heat. Cover; simmer on low heat 10 min., stirring occasionally.
Remove from heat. (Do not drain.) Set aside.
Melt butter in separate large saucepan on low heat. Stir in flour; cook and stir 2 min. or until bubbly. Gradually stir in milk until blended. Bring to boil on medium heat, stirring frequently; cook 1 to 2 min. or until thickened, stirring constantly. Simmer on low heat 5 min.
Add cheese; cook and stir 2 min. or until melted.
Add corn and undrained cooked vegetables; cook 5 min. or until heated through, stirring occasionally. (Do not boil.)