Set oven temperature to 400 degrees.
Add the flour, sugar, baking powder, zest from the lemon, and salt to a large food processor. Pulse to mix.
Add the butter and pulse approximately ten times, or until it resembles coarse crumbs.
Slowly pour in the milk and pulse to barely moisten.
Transfer the mixture to a bowl, stir in the blueberries, and fold to blend.
Turn out the ingredients onto a large floured surface.
After generously flouring your rolling pin, spread out the mixture to a thickness of 1/2".
Use a 2-and a 3-inch biscuit cutter to cut.
Bake until light golden brown, 15 to 18 minutes.
Give biscuits five minutes to cool.
Combine water, lemon juice, and powdered sugar.
Over the biscuits, drizzle the mixture.