Preheat the oven to 350°F. Spray a 9×5″ loaf pan with non-stick cooking spray and set aside.
In a large bowl beat the sugar, eggs and vegetable oil. Then add the buttermilk and vanilla. Mix until smooth. Next add in the flour, baking powder and baking soda. Stir until combined. Fold in the zucchini, blueberries, the zest from 2 lemons and the juice from 1 lemon.
Pour the batter into the pan and then bake for 40-50 minutes, or until a toothpick comes clean. Cool in pan for about 15 minutes and then flip over onto a cooling rack.
Once the bread has cooled, whisk together the powdered sugar and juice from 1 lemon. Then pour over the top of the bread.
To remove the water from the zucchini, simply place in in a cheesecloth or paper towels and squeeze the water out over a sink.