Heat oven to 350°F. Lightly grease a small (6-cup) Bundt cake pan or an 8 x 4-inch loaf pan.
In a large mixing bowl, stir together cake mix, water, melted butter, and egg until blended.
In a separate small bowl, toss the blueberries with flour to coat them. Gently fold the blueberries into the cake batter. Spoon the batter into prepared pan.
Bake 40-45 minutes or until toothpick inserted into center comes out clean. Transfer to a cooling rack and cool 5 minutes in pan.
Gently loosen and remove from pan. Cool cake completely before drizzling with glaze.
For Glaze: Whisk together lemon glaze mix from package and water until glaze is desired consistency. Drizzle over cooled pound cake. Allow glaze to set before serving.